View source for Venus

{{Short description|Second planet from the Sun}}
{{About|the planet|the deity|Venus (mythology)|other uses}}
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{{Use dmy dates|date=August 2024}}
{{Use Oxford spelling|date=August 2024}}
{{Infobox planet
| name = Venus
| image = Venus 2 Approach Image.jpg 
| symbol = [[File:Venus symbol (bold).svg|24px|♀]]
| caption = True colour image of Venus, as captured by ''[[MESSENGER]]''. A cloud layer permanently obscures the surface.
| background = Beige
| orbit_ref = <ref name="fact" /><ref name="horizons" />
| epoch = [[J2000]]
| aphelion = {{convert|0.728213|AU|e6km|2|abbr=unit|lk=in}}
| perihelion = {{convert|0.718440|AU|e6km|2|abbr=unit}}
| semimajor = {{convert|0.723332|AU|e6km|2|abbr=unit}}
| eccentricity = 0.006772<ref name="VSOP87" />
| period = {{plainlist |
* {{val|224.701|u=day}}<ref name="fact" />
* {{val|0.615198|u=[[julian year (astronomy)|yr]]}}
* 1.92 Venus [[solar day]]
  }}
| synodic_period = 583.92 days<ref name="fact" />
| avg_speed = 35.02{{spaces}}km/s
| inclination = {{plainlist |
* {{val|3.39458|u=°}} to [[ecliptic]]
* 3.86° to [[Sun]]'s [[equator]]
* 2.15° to [[invariable plane]]<ref name=Souami_Souchay_2012 />
  }}
| asc_node = 76.680°<ref name="VSOP87" />
| arg_peri = 54.884°
| mean_anomaly = 50.115°
| satellites = None
| allsatellites = yes
| mean_radius = {{plainlist |
* {{nowrap|{{val|fmt=commas|6051.8|1.0|u=km}}}}<ref name="Seidelmann2007" />
* {{val|0.9499|u=Earths}}
  }}
| flattening = 0<ref name="Seidelmann2007" />
| surface_area = {{plainlist |
* {{val|4.6023|e=8|u=km2}}
* 0.902 Earths
  }}
| volume = {{plainlist |
* {{val|9.2843|e=11|u=km3}}
* 0.857 Earths
  }}
| mass = {{plainlist |
* {{val|4.8675|e=24|u=kg}}<ref name="Konopliv1999" />
* 0.815 Earths
  }}
| density = {{val|5.243|u=g/cm3}}
| surface_grav = {{cvt|8.87|m/s2|g0|lk=out}}
| escape_velocity = {{convert|10.36|km/s|abbr=on}}<ref name=NASA_2015/>
| rotation = {{val|-116.75|u=day}} ([[Retrograde motion|retrograde]])<ref name="planetary-facts"/>
<br />1 Venus solar day
| sidereal_day = {{val|-243.0226|u=day}} (retrograde)<ref name=Margot_et_al_2021/>
| rot_velocity = {{cvt|6.52|km/h|m/s|disp=out}}<!--Since rot. vel. = circumference/sidereal day, and circumference is 2πr, rot. vel. = 2π6051km/243.025*24h = 6.52 km/h-->
| axial_tilt = 2.64° (for [[Retrograde motion|retrograde]] rotation){{break}}177.36° (to orbit)<ref name=fact/>{{refn|group=note|Defining the rotation as retrograde, as done by NASA space missions and the USGS, puts [[Ishtar Terra]] in the northern hemisphere and makes the axial tilt 2.64°. Following the [[right-hand rule]] for prograde rotation puts Ishtar Terra in the negative hemisphere and makes the axial tilt 177.36°.}}
| right_asc_north_pole = {{plainlist |
* {{RA|18|11|2}}
* 272.76° <ref name="iauwg_ccrsps2000" /><ref name="iau2015">{{Cite journal |last1=Archinal |first1=B. A. |last2=Acton |first2=C. H. |last3=A'Hearn |first3=M. F. |last4=Conrad |first4=A. |last5=Consolmagno |first5=G. J. |last6=Duxbury |first6=T. |last7=Hestroffer |first7=D. |last8=Hilton |first8=J. L. |last9=Kirk |first9=R. L. |last10=Klioner |first10=S. A. |last11=McCarthy |first11=D. |last12=Meech |first12=K. |last13=Oberst |first13=J. |last14=Ping |first14=J. |last15=Seidelmann |first15=P. K. |date=2018 |title=Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015 |url=http://link.springer.com/10.1007/s10569-017-9805-5 |journal=Celestial Mechanics and Dynamical Astronomy |language=en |volume=130 |issue=3 |page=22 |doi=10.1007/s10569-017-9805-5 |bibcode=2018CeMDA.130...22A |issn=0923-2958}}</ref>
  }}
| declination = 67.16° <ref name="iau2015" />
| albedo = {{plainlist |
* 0.689 ([[Geometric albedo|geometric]])<ref name="Mallama_et_al"/>
* 0.76 ([[Bond albedo|Bond]])<ref name="Haus_et_al"/>
  }}
| magnitude = −4.92 to −2.98<ref name="Mallama_and_Hilton"/>
| abs_magnitude = −4.4<ref name="IMCCE">{{cite web | title=Encyclopedia – the brightest bodies | website=IMCCE | url=https://promenade.imcce.fr/en/pages5/572.html | access-date=29 May 2023 | archive-date=24 July 2023 | archive-url=https://web.archive.org/web/20230724225002/https://promenade.imcce.fr/en/pages5/572.html | url-status=live }}</ref>
| angular_size = {{nowrap|9.7″–66.0″}}<ref name="fact" />
| single_temperature = {{cvt|232|K|°C|0}} ([[Effective temperature|blackbody temperature]])<ref name="American Chemical Society 2013"/>
| temp_name1 = [[Kelvin]]
| mean_temp_1 = 737 K<ref name="fact" />
| temp_name2 = [[Celsius]]
| mean_temp_2 = 464 °C
| temp_name3 = [[Fahrenheit]]
| mean_temp_3 = 867 °F
| surface_equivalent_dose_rate = {{convert |{{#expr:10^(19/54)}}e-9 |mSv/h |μSv/h |sigfig=2 |disp=out}}<br/>{{convert |{{#expr:10^(52/54)}}e-5 |- |{{#expr:10^(19/54)}}e-2 |mSv/h |μSv/h |sigfig=2 |disp=out}} at cloud level<ref name="radiation-levels"/><!-- pixel values measured from the referenced figure -->
| surface_absorbed_dose_rate = {{convert |{{#expr:10^(17/54)}}e-9 |mGy/h |μGy/h |sigfig=2 |disp=out}}<ref name="radiation-levels"/>
| pronounced = {{IPAc-en|audio=en-us-Venus.ogg|ˈ|v|iː|n|ə|s}}
| named_after = [[Roman religion|Roman]] [[List of love and lust deities|goddess of love]] (see [[goddess Venus]])
| adjectives = {{nowrap|[[Venusian (disambiguation)|Venusian]] {{IPAc-en|v|ᵻ|ˈ|nj|uː|z|i|ə|n|,_|-|ʒ|ə|n}},<ref name=Lexico_Venusian/>}} rarely [[Cytherean]] {{IPAc-en|s|ɪ|θ|ə|'|r|iː|ə|n}}<ref>{{OED|Cytherean}}</ref> or Venerean / Venerian {{IPAc-en|v|ᵻ|ˈ|n|ɪər|i|ə|n}}<ref>{{OED|Venerean, Venerian}}</ref>
| atmosphere = yes
| atmosphere_ref = <ref name="fact" />
| surface_pressure = 93&nbsp;[[bar (unit)|bar]] (9.3&nbsp;[[Pascal (unit)|MPa]]){{break}}92 [[atmosphere (unit)|atm]]
| atmosphere_composition = {{plainlist | 
* 96.5% [[carbon dioxide]]
* 3.5% [[nitrogen]]
* 0.015% [[sulphur dioxide]]
* 0.0070% [[argon]]
* 0.0020% [[water vapour]]
* 0.0017% [[carbon monoxide]]
* 0.0012% [[helium]]
* 0.0007% [[neon]]
* Trace [[carbonyl sulfide]]
* Trace [[hydrogen chloride]]
* Trace [[hydrogen fluoride]]
  }}
}}'''Venus''' is the second [[planet]] from the [[Sun]]. It is a [[terrestrial planet]] and is the closest in [[List of Solar System objects by size|mass and size]] to its orbital neighbour [[Earth]]. Venus has [[Atmosphere of Venus|by far the densest atmosphere]] of the terrestrial planets, composed mostly of [[carbon dioxide]] with a thick, global [[sulfuric acid]] cloud cover. At the surface it has a mean temperature of {{convert|737|K|C F|abbr=on}} and a [[atmospheric pressure|pressure]] of 92 times that of Earth's at sea level. These extreme conditions compress carbon dioxide into a [[supercritical fluid|supercritical state]] at Venus's surface.

Internally, Venus has a [[Planetary core|core]],&nbsp;[[Mantle (geology)|mantle]], and&nbsp;[[Crust (geology)|crust]]. Venus lacks an internal dynamo, and its weakly [[Atmosphere of Venus#Induced magnetosphere|induced magnetosphere]] is caused by atmospheric interactions with the [[solar wind]]. [[Internal heat]] escapes through [[Volcanism on Venus|active volcanism]],<ref name="NYT-20240527">{{cite news |last=Andrews |first=Roy George |title=Rivers of Lava on Venus Reveal a More Volcanically Active Planet - New software let scientists re-examine old radar images, providing some of the strongest evidence yet that volcanoes continue to reshape the hellish planet. |url=https://www.nytimes.com/2024/05/27/science/venus-volcanoes-lava.html |date=27 May 2024 |work=[[The New York Times]] |url-status=live |archiveurl=https://archive.today/20240528023048/https://www.nytimes.com/2024/05/27/science/venus-volcanoes-lava.html |archivedate=28 May 2024 |accessdate=28 May 2024 }}</ref><ref name="NA-20240527">{{cite journal |last1=Sulcanese |first1=Davide |last2=Mitri |first2=Giuseppe |last3=Mastrogiuseppe |first3=Marco |title=Evidence of ongoing volcanic activity on Venus revealed by Magellan radar |url=https://www.nature.com/articles/s41550-024-02272-1 |date=27 May 2024 |journal=[[Nature Astronomy]] |volume=8 |issue=8 |pages=973–982 |doi=10.1038/s41550-024-02272-1 |bibcode= 2024NatAs...8..973S|url-status=live |archiveurl=https://archive.today/20240528101249/https://www.nature.com/articles/s41550-024-02272-1 |archivedate=28 May 2024 |accessdate=28 May 2024 | issn = 2397-3366 }}</ref> resulting in [[Large igneous province|resurfacing]] instead of [[plate tectonics]]. Venus is one of two planets in the [[Solar System]], the other being [[Mercury (planet)|Mercury]], that have no [[moons]].<ref name="NASA_2019" /> Conditions perhaps favourable for [[life on Venus]] have been identified at its cloud layers. Venus may have had liquid surface water early in its history with a [[Planetary habitability|habitable environment]],<ref name="NYT-20231026" /><ref name="NA-20231026" /> before a [[runaway greenhouse effect]] evaporated any water and turned Venus into its present state.<ref name="Jakosky" /><ref name="Hashimoto_et_al_2008" /><ref name="Shiga_2007" />

The rotation of Venus has been slowed and turned against its orbital direction ([[Retrograde and prograde motion|retrograde]]) by the currents and drag of its atmosphere.<ref name="Kane_2022">{{cite journal |last1=Kane |first1=Stephen  |title= Atmospheric dynamics of a near tidally locked Earth-sized planet  |url=https://www.nature.com/articles/s41550-022-01626-x |date=22 April 2022 |journal=[[Nature Astronomy]] |volume=6 |issue=4 |pages=420–427 |doi=10.1038/s41550-022-01626-x |arxiv=2204.09696 |bibcode=2022NatAs...6..420K }}</ref> It takes 224.7 Earth days for Venus to complete an orbit around the Sun, and a Venusian [[solar year]] is just under two Venusian days long. The orbits of Venus and Earth are the closest between any two Solar System planets, approaching each other in [[synodic period]]s of 1.6 years. Venus and Earth have the lowest difference in [[gravitational potential]] of any pair of Solar System planets. This allows Venus to be the most [[Delta-v budget|accessible]] destination and a useful [[gravity assist]] waypoint for [[interplanetary mission|interplanetary flights]] from Earth.

Venus figures prominently [[Venus in culture|in human culture]] and in the history of astronomy. Orbiting [[inferior planet|inferiorly]] (inside of Earth's orbit), it always appears close to the Sun in Earth's sky, as either a "morning star" or an "evening star". While this is also true for [[Mercury (planet)|Mercury]], Venus appears more prominent, since it is the [[List of brightest natural objects in the sky|third brightest object in Earth's sky]] after the [[Moon]] and the Sun.<ref name="Lawrence_2005" /><ref name="Walker_2017" /> In 1961, Venus became the target of the first interplanetary flight, [[Venera 1]], followed by many essential [[Timeline of Solar System exploration|interplanetary firsts]], such as the first soft landing on another planet by [[Venera 7]] in 1970. These probes demonstrated the extreme surface conditions, an insight that has informed predictions about [[global warming]] on Earth.<ref name="Newitz 2013"/> This finding ended the theories and then popular [[Venus in fiction|science fiction about Venus]] being a habitable or inhabited planet.

== Physical characteristics ==
[[File:Terrestrial planet size comparisons-2.jpg|thumb|upright=1.4|Venus to scale among the [[Inner Solar System]] [[planetary-mass object]]s beside the Sun, arranged by the order of their orbits outward from the Sun (from left: [[Mercury (planet)|Mercury]], Venus,
[[Earth]], the [[Moon]], [[Mars]] and [[Ceres (dwarf planet)|Ceres]])]]
Venus is one of the four [[terrestrial planet]]s in the Solar System, meaning that it is a rocky body like Earth. It is similar to Earth in size and mass and is often described as Earth's "sister" or "twin".<ref name= "Lopes_Gregg_2004"/> Venus is close to spherical due to its slow rotation.<ref name="Venus"/> Venus has a diameter of {{convert|12103.6|km|mi|abbr=on}}—only {{convert|638.4|km|mi|abbr=on}} less than Earth's—and its mass is 81.5% of Earth's, making it the third-smallest planet in the [[Solar System]]. Conditions on the Venusian surface differ radically from those on Earth because its dense [[atmosphere]] is 96.5% carbon dioxide, with most of the remaining 3.5% being [[nitrogen]].<ref name=Darling_Venus/> The surface pressure is {{convert|9.3|MPa|bar|lk=on|abbr=off}}, and the average surface temperature is {{convert|737|K|C F|abbr=on}}, above the [[Critical point (thermodynamics)|critical points]] of both major constituents and making the surface atmosphere a [[supercritical fluid]] out of mainly [[supercritical carbon dioxide]] and some supercritical nitrogen.

=== Geography ===
{{Main|Geology of Venus|Geodynamics of Venus|Mapping of Venus|Surface features of Venus}}

[[File:2438_pioneer_venus_map_of_venus.jpg|thumb|upright=1.5|Color-coded elevation map, showing the elevated [[Planetary nomenclature#Terra|terrae]] "continents" in yellow and minor [[Surface features of Venus|features of Venus]].]]

The Venusian surface was a subject of speculation until some of its secrets were revealed by [[planetary science]] in the 20th century. ''[[Venera]]'' landers in 1975 and 1982 returned images of a surface covered in sediment and relatively angular rocks.<ref name=Mueller_2014/> The surface was mapped in detail by ''Magellan'' in 1990–91. The ground shows evidence of extensive volcanism, and the [[sulphur]] in the atmosphere may indicate that there have been recent eruptions.<ref name=Esposito_1984/><ref name=Bullock_Grinspoon_2001/>

About 80% of the Venusian surface is covered by smooth, volcanic plains, consisting of 70% plains with wrinkle ridges and 10% smooth or lobate plains.<ref name=Basilevsky_Head_1995/> Two [[highland continent|highland "continents"]] make up the rest of its surface area, one lying in the planet's northern hemisphere and the other just south of the equator. The northern continent is called [[Ishtar Terra]] after [[Ishtar]], the [[Babylon]]ian goddess of love, and is about the size of Australia. [[Maxwell Montes]], the highest mountain on Venus, lies on Ishtar Terra. Its peak is {{convert|7|mi|km|order=flip|abbr=on}} above the Venusian average surface elevation.<ref name="planetology"/> The southern continent is called [[Aphrodite Terra]], after the [[Greek mythological]] goddess of love, and is the larger of the two highland regions at roughly the size of South America. A network of fractures and faults covers much of this area.<ref name="Kaufmann"/>

There is recent evidence of [[lava]] flow on Venus (2024),<ref>National Geographic [https://www.nationalgeographic.com/science/article/venus-is-volcanically-alive (2024) Venus is volcanically alive]</ref> such as flows on Sif Mons, a shield volcano, and on Niobe Planitia, a flat plain.<ref>The New York Times [https://www.nytimes.com/2024/05/27/science/venus-volcanoes-lava.html (27 May 2024) Rivers of Lava on Venus Reveal a More Volcanically Active Planet]</ref> There are visible [[caldera]]s. The planet has few [[impact crater]]s, demonstrating that the surface is relatively young, at 300–600{{spaces}}million years old.<ref name="Nimmo98" /><ref name="Strom1994" /> Venus has some unique surface features in addition to the impact craters, mountains, and valleys commonly found on rocky planets. Among these are flat-topped volcanic features called "[[Farra (Venus)|farra]]", which look somewhat like pancakes and range in size from {{convert|20|to|50|km|mi|abbr=on}} across, and from {{convert|100|to|1000|m|ft|abbr=on}} high; radial, star-like fracture systems called "novae"; features with both radial and concentric fractures resembling spider webs, known as "[[arachnoid (astrogeology)|arachnoids]]"; and "coronae", circular rings of fractures sometimes surrounded by a depression. These features are volcanic in origin.<ref name="Frankel"/>

[[File:Surface of Venus from Venera 13.jpg|thumb|Surface panorama taken by Venera 13]]

Most [[List of geological features on Venus|Venusian surface features]] are named after historical and mythological women.<ref name=Batson_Russell_1991/> Exceptions are Maxwell Montes, named after [[James Clerk Maxwell]], and highland regions [[Alpha Regio]], [[Beta Regio]], and [[Ovda Regio]]. The last three features were named before the current system was adopted by the [[International Astronomical Union]], the body which oversees [[planetary nomenclature]].<ref name="jpl-magellan"/>

The longitude of physical features on Venus is expressed relative to its [[prime meridian]]. The original prime meridian passed through the radar-bright spot at the centre of the oval feature Eve, located south of Alpha Regio.<ref name="Davies_1994"/> After the Venera missions were completed, the prime meridian was redefined to pass through the central peak in the [[Ariadne (crater)|crater Ariadne]] on [[Sedna Planitia]].<ref name=Seidelmann_et_al_2007/><ref name="jpl-magellan2"/>
 
The stratigraphically oldest [[Tessera (Venus)|tessera terrains]] have consistently lower thermal emissivity than the surrounding basaltic plains measured by ''[[Venus Express]]'' and [[Magellan (spacecraft)|''Magellan'']], indicating a different, possibly a more [[felsic]], mineral assemblage.<ref name="Hashimoto_et_al_2008"/><ref name=Helbert_et_al_2008/> The mechanism to generate a large amount of felsic crust usually requires the presence of water ocean and [[plate tectonics]], implying that habitable condition had existed on early Venus with large bodies of water at some point.<ref name="Petkowski Seager 2021">{{cite web | last1=Petkowski | first1=Janusz | last2=Seager | first2=Sara | title=Did Venus ever have oceans? | website=Venus Cloud Life – MIT | date=18 November 2021 | url=https://venuscloudlife.com/are-venus-cloud-layers-too-dry-for-life/ | access-date=13 April 2023 | archive-date=13 April 2023 | archive-url=https://web.archive.org/web/20230413112527/https://venuscloudlife.com/are-venus-cloud-layers-too-dry-for-life/ | url-status=live }}</ref> However, the nature of tessera terrains is far from certain.<ref name=Gilmore_et_al_2017/>

Studies reported on 26 October 2023 suggest for the first time that Venus may have had [[plate tectonics]] during ancient times and, as a result, may have had a more [[Planetary habitability|habitable environment]], possibly one capable of sustaining [[life forms|life]].<ref name="NYT-20231026">{{cite news |last=Chang |first=Kenneth |title=Billions of Years Ago, Venus May Have Had a Key Earthlike Feature – A new study makes the case that the solar system's hellish second planet once may have had plate tectonics that could have made it more hospitable to life. |url=https://www.nytimes.com/2023/10/26/science/venus-plate-tectonics-life.html |date=26 October 2023 |work=[[The New York Times]] |url-status=live |archive-url=https://archive.today/20231026181052/https://www.nytimes.com/2023/10/26/science/venus-plate-tectonics-life.html |archive-date=26 October 2023 |access-date=27 October 2023 }}</ref><ref name="NA-20231026">{{cite journal |author=Weller, Matthew B. |display-authors=et al. |title=Venus's atmospheric nitrogen explained by ancient plate tectonics |url=https://www.nature.com/articles/s41550-023-02102-w |date=26 October 2023 |journal=[[Nature Astronomy]] |volume=7 |issue=12 |pages=1436–1444 |doi=10.1038/s41550-023-02102-w |bibcode=2023NatAs...7.1436W |s2cid=264530764 |url-status=live |archive-url=https://archive.today/20231027132655/https://www.nature.com/articles/s41550-023-02102-w |archive-date=27 October 2023 |access-date=27 October 2023 |url-access=subscription }}</ref> Venus has gained interest as a case for research into the development of [[Earth analogue|Earth-like planets]] and [[planetary habitability|their habitability]].

==== Volcanism ====
{{Main|Volcanism on Venus}}
[[Image:PIA00084 Eistla region pancake volcanoes.jpg|thumb|left|Radar mosaic of two {{Convert|65|km|mi|abbr=on}} wide (and less than {{Convert|1|km|mi|abbr=on}} high) [[pancake dome]]s in Venus's Eistla region]]

Much of the Venusian surface appears to have been shaped by volcanic activity. Venus has several times as many volcanoes as Earth, and it has 167 large volcanoes that are over {{convert|100|km|mi|sigfig=1|abbr=on}} across. The only volcanic complex of this size on Earth is the [[Hawaii (island)|Big Island]] of Hawaii.<ref name="Frankel" />{{rp|154}} More than 85,000 volcanoes on Venus were identified and mapped.<ref>{{cite web |title=A new catalog pinpoints volcanic cones in the best available surface images of Venus – those gathered 30 years ago by NASA's Magellan spacecraft. |url=https://skyandtelescope.org/astronomy-news/85000-volcanoes-mapped-on-venus |website=skyandtelescope.org |access-date=16 April 2023 |archive-date=16 April 2023 |archive-url=https://web.archive.org/web/20230416223821/https://skyandtelescope.org/astronomy-news/85000-volcanoes-mapped-on-venus/ |url-status=live }}</ref><ref>{{cite journal |last1=Hahn |first1=Rebecca M. |last2=Byrne |first2=Paul K. |title=A Morphological and Spatial Analysis of Volcanoes on Venus |journal=Journal of Geophysical Research: Planets |date=April 2023 |volume=128 |issue=4 |pages=e2023JE007753 |doi=10.1029/2023JE007753 |bibcode=2023JGRE..12807753H |s2cid=257745255 |quote=With the Magellan synthetic-aperture radar full-resolution radar map left- and right-look global mosaics at 75 m-per-pixel resolution, we developed a global catalogue of volcanoes on Venus that contains ~85,000 edifices, ~99% of which are <5 km in diameter. We find that Venus hosts far more volcanoes than previously mapped, and that although they are distributed across virtually the entire planet, size–frequency distribution analysis reveals a relative lack of edifices in the 20–100 km diameter range, which could be related to magma availability and eruption rate.}}</ref> This is not because Venus is more volcanically active than Earth, but because its crust is older and is not subject to the same [[erosion]] process. Earth's [[oceanic crust]] is continually recycled by [[subduction]] at the boundaries of tectonic plates, and has an average age of about 100 million years,<ref name=Karttunen_et_al_2007/> whereas the Venusian surface is estimated to be 300–600{{spaces}}million years old.<ref name="Nimmo98" /><ref name="Frankel" />

Several lines of evidence point to ongoing [[volcanic]] activity on Venus. Sulfur dioxide concentrations in the upper atmosphere dropped by a factor of 10 between 1978 and 1986, jumped in 2006, and again declined 10-fold.<ref name="ESA_2012-12-03"/> This may mean that levels had been boosted several times by large volcanic eruptions.<ref name=Glaze_1999/><ref name="Marcq2012"/> It has been suggested that Venusian lightning (discussed below) could originate from volcanic activity (i.e. [[volcanic lightning]]). In January 2020, astronomers reported evidence that suggests that Venus is currently volcanically active, specifically the detection of [[olivine]], a volcanic product that would weather quickly on the planet's surface.<ref name="NYT-20200109"/><ref name="SCI-20200103"/>

This massive volcanic activity is fuelled by a superheated interior, which models say could be explained by energetic collisions from when the planet was young. Impacts would have had significantly higher velocity than on Earth, both because Venus's orbit is faster due to its closer proximity to the Sun and because objects would require higher orbital eccentricities to collide with the planet.<ref>{{Cite web |url=https://www.sci.news/space/venus-volcanism-12114.html |title=Early, Energetic Collisions Could Have Fueled Venus Volcanism: Study {{!}} Sci.News |date=20 July 2023 |access-date=21 July 2023 |archive-date=21 July 2023 |archive-url=https://web.archive.org/web/20230721193015/https://www.sci.news/space/venus-volcanism-12114.html |url-status=live }}</ref>

In 2008 and 2009, the first direct evidence for ongoing volcanism was observed by ''Venus Express'', in the form of four transient localized infrared hot spots within the rift zone [[Ganis Chasma]],<ref name="USGS_Ganis_Chasma"/>{{refn|group=note|Misstated as "Ganiki Chasma" in the press release and scientific publication.<ref name = "Lakdawalla2015"/>}} near the shield volcano [[Maat Mons]]. Three of the spots were observed in more than one successive orbit. These spots are thought to represent lava freshly released by volcanic eruptions.<ref name="Lakdawalla2015"/><ref name="ESA_2015-06-18"/> The actual temperatures are not known, because the size of the hot spots could not be measured, but are likely to have been in the {{convert|800|-|1100|K|C F}} range, relative to a normal temperature of {{convert|740|K|C F}}.<ref name="Shalygin2015"/> In 2023, scientists reexamined topographical images of the Maat Mons region taken by the ''[[Magellan (spacecraft)|Magellan]]'' orbiter. Using computer simulations, they determined that the topography had changed during an 8-month interval, and concluded that active volcanism was the cause.<ref>{{cite web | title=Why the Discovery of an Active Volcano on Venus Matters | last=Kluger | first=Jeffrey | url=https://time.com/6264160/why-volcanoes-on-venus-matter/ | publisher=[[Time (magazine)|Time]] | date=17 March 2023 | access-date=19 March 2023 | archive-date=19 March 2023 | archive-url=https://web.archive.org/web/20230319022005/https://time.com/6264160/why-volcanoes-on-venus-matter/ | url-status=live }}</ref>

==== Craters ====
[[File:PIA00103 Venus - 3-D Perspective View of Lavinia Planitia.jpg|thumb|alt=The plains of Venus|[[Impact crater]]s on the surface of Venus (false-colour image reconstructed from radar data)]]

Almost a thousand impact craters on Venus are evenly distributed across its surface. On other cratered bodies, such as Earth and the Moon, craters show a range of states of degradation. On the Moon, degradation is caused by subsequent impacts, whereas on Earth it is caused by wind and rain erosion. On Venus, about 85% of the craters are in pristine condition. The number of craters, together with their well-preserved condition, indicates the planet underwent a global resurfacing event 300–600{{spaces}}million years ago,<ref name="Nimmo98" /><ref name="Strom1994"/> followed by a decay in volcanism.<ref name=Romeo_Turcotte_2018/> Whereas Earth's crust is in continuous motion, Venus is thought to be unable to sustain such a process. Without plate tectonics to dissipate heat from its mantle, Venus instead undergoes a cyclical process in which mantle temperatures rise until they reach a critical level that weakens the crust. Then, over a period of about 100{{spaces}}million years, subduction occurs on an enormous scale, completely recycling the crust.<ref name="Frankel" />

Venusian craters range from {{convert|3|to|280|km|mi|0|abbr=on}} in diameter. No craters are smaller than 3{{spaces}}km, because of the effects of the dense atmosphere on incoming objects. Objects with less than a certain [[kinetic energy]] are slowed so much by the atmosphere that they do not create an impact crater.<ref name=Herrick_Phillips_1993/> Incoming projectiles less than {{convert|50|m|ft|-1|abbr=on}} in diameter will fragment and burn up in the atmosphere before reaching the ground.<ref name=Morrison_Owens_2003/>

=== Internal structure ===
[[File:InteriorOfVenus.svg|thumb|The [[Planetary differentiation|differentiated]] structure of Venus|alt=Spherical cross-section of Venus showing the different layers]]

Without data from [[reflection seismology]] or knowledge of its [[moment of inertia]], little direct information is available about the internal structure and [[geochemistry]] of Venus.<ref name="goettel"/> The similarity in size and density between Venus and Earth suggests that they share a similar internal structure: a [[Planetary core|core]], [[Mantle (geology)|mantle]], and [[Crust (geology)|crust]]. Like that of Earth, the Venusian core is most likely at least partially liquid because the two planets have been cooling at about the same rate,<ref name=Faure_Mensing_2007/> although a completely solid core cannot be ruled out.<ref name=Dumoulin2017/> The slightly smaller size of Venus means pressures are 24% lower in its deep interior than Earth's.<ref name=Aitta_2016/> The predicted values for the moment of inertia based on planetary models suggest a core radius of 2,900–3,450&nbsp;km.<ref name=Dumoulin2017/> This is in line with the first observation-based estimate of 3,500&nbsp;km.<ref name="O'Callaghan_2021"/>

The principal difference between the two planets is the lack of evidence for plate tectonics on Venus, possibly because its crust is too strong to [[subduct]] without water to make it less [[viscous]]. This results in reduced heat loss from the planet, preventing it from cooling and providing a likely explanation for its lack of an internally generated [[magnetic field]].<ref name=Nimmo_2002/> Instead, Venus may lose its internal heat in periodic major resurfacing events.<ref name="Nimmo98"/>

=== Magnetic field and core ===

In 1967, ''[[Venera 4]]'' found Venus's [[magnetic field]] to be much weaker than that of Earth. This magnetic field is induced by an interaction between the [[ionosphere]] and the [[solar wind]],<ref name=Eroshenko_et_al_1969/><ref name=Kivelson_Russell_1995/>{{Page needed|date=January 2023}} rather than by an internal [[dynamo theory|dynamo]] as in the Earth's [[Planetary core|core]]. [[Magnetosphere of Venus|Venus's small induced magnetosphere]] provides negligible protection to the atmosphere against [[solar radiation|solar]] and [[cosmic radiation]].

The lack of an intrinsic magnetic field on Venus was surprising, given that it is similar to Earth in size and was expected to contain a dynamo at its core. A dynamo requires three things: a [[Electrical conductor|conducting]] liquid, rotation, and [[convection]]. The core is thought to be electrically conductive and, although its rotation is often thought to be too slow, simulations show it is adequate to produce a dynamo.<ref name=Luhmann_Russell_2006/><ref name=Stevenson_2003/> This implies that the dynamo is missing because of a lack of convection in Venus's core. On Earth, convection occurs in the liquid outer layer of the core because the bottom of the liquid layer is much higher in temperature than the top. On Venus, a global resurfacing event may have shut down plate tectonics and led to a reduced [[heat flux]] through the crust. This [[Thermal insulation|insulating]] effect would cause the mantle temperature to increase, thereby reducing the heat flux out of the core. As a result, no internal geodynamo is available to drive a magnetic field. Instead, the heat from the core is reheating the crust.<ref name="nimmo02"/>

One possibility is that Venus has no solid inner core,<ref name=Konopliv_Yoder_1996/> or that its core is not cooling, so that the entire liquid part of the core is at approximately the same temperature. Another possibility is that its core has already been completely solidified. The state of the core is highly dependent on the concentration of [[sulphur]], which is unknown at present.<ref name="nimmo02" />

Another possibility is that the absence of a late, large impact on Venus (''contra'' the Earth's "Moon-forming" impact) left the core of Venus stratified from the core's incremental formation, and without the forces to initiate/sustain convection, and thus a "geodynamo".<ref name="Jacobsen2017">{{cite journal | last1=Jacobson | first1=Seth A. | last2=Rubie | first2=David C. | last3=Hernlund | first3=John | last4=Morbidelli | first4=Alessandro | last5=Nakajima | first5=Miki | title=Formation, stratification, and mixing of the cores of Earth and Venus | journal=Earth and Planetary Science Letters | publisher=Elsevier BV | volume=474 | year=2017 | doi=10.1016/j.epsl.2017.06.023 | page=375| arxiv=1710.01770 | bibcode=2017E&PSL.474..375J | s2cid=119487513 }}</ref>

The weak magnetosphere around Venus means that the solar wind is interacting directly with its outer atmosphere. Here, ions of hydrogen and oxygen are being created by the [[Dissociation (chemistry)|dissociation]] of water molecules from [[ultraviolet]] radiation. The solar wind then supplies energy that gives some of these ions sufficient velocity to escape Venus's gravity field. This erosion process results in a steady loss of low-mass hydrogen, helium, and oxygen ions, whereas higher-mass molecules, such as carbon dioxide, are more likely to be retained. Atmospheric erosion by the solar wind could have led to the loss of most of Venus's water during the first billion years after it formed.<ref name="nature450_7170_629"/> However, the planet may have retained a dynamo for its first 2–3 billion years, so the water loss may have occurred more recently.<ref name="O'Rourke_et_al_2019"/> The erosion has increased the ratio of higher-mass [[deuterium]] to lower-mass hydrogen in the atmosphere 100 times compared to the rest of the solar system.<ref name=Donahue_et_al_1982/>

== Atmosphere and climate ==
{{Main|Atmosphere of Venus}}
[[File:Venus - December 23 2016.png|alt=The atmosphere of Venus appears darker and lined with shadows. The shadows trace the prevailing wind direction.|thumb|Cloud structure of the Venusian atmosphere, made visible through [[ultraviolet]] imaging]]

Venus has a dense [[atmosphere]] composed of 96.5% [[carbon dioxide]], 3.5% nitrogen—both exist as supercritical fluids at the planet's surface with a density 6.5% that of water<ref name="u3r1a"/>—and traces of other gases including [[sulphur dioxide]].<ref name="SolarSystemEncyclopedia"/> The mass of its atmosphere is 92 times that of Earth's, whereas the pressure at its surface is about 93 times that at Earth's—a pressure equivalent to that at a depth of nearly {{convert|1|km|mi|frac=8|abbr=on}} under Earth's ocean surfaces. The density at the surface is {{Convert|65|kg/m3|lb/ft3|abbr=on}}, 6.5% that of water<ref name="u3r1a"/> or 50 times as dense as Earth's atmosphere at {{convert|20|C|K C F|0|order=out}} at sea level. The {{chem2|CO2}}-rich atmosphere generates the strongest [[greenhouse effect]] in the Solar System, creating surface temperatures of at least {{convert|462|C|K C F|order=out}}.<ref name="nasa_venus" /><ref name=CWRU_2006/> This makes the Venusian surface hotter than [[Mercury (planet)|Mercury]]'s, which has a minimum surface temperature of {{convert|−220|C|K C F|0|order=out|round=5}} and maximum surface temperature of {{convert|427|C|K C F|0|order=out|round=5}},<ref name=Lewis_2004/><ref name=Prockter_2005/> even though Venus is nearly twice Mercury's distance from the Sun and thus receives only 25% of Mercury's solar [[irradiance]], of 2,600 W/m<sup>2</sup> (double that of Earth).<ref name="fact" /> Because of its [[runaway greenhouse effect]], Venus has been identified by scientists such as [[Carl Sagan]] as a warning and research object linked to [[climate change]] on Earth.<ref name="Newitz 2013"/>

{|class="wikitable floatleft" style="font-size: 100%; margin-right: 1em;"
|+ Venus temperature<ref name=Weather/> 
|-
! Type || Surface<br />temperature
|-
| Maximum || 900&nbsp;°F (482&nbsp;°C)
|-
| Normal || 847&nbsp;°F (453&nbsp;°C)
|-
| Minimum || 820&nbsp;°F (438&nbsp;°C)
|}

Venus's atmosphere is rich in primordial [[noble gas]]es compared to that of Earth.<ref name=Halliday_2020/> This enrichment indicates an early divergence from Earth in evolution. An unusually large comet impact<ref name=Owen_et_al_1992/> or accretion of a more massive [[primary atmosphere]] from solar nebula<ref name=Pepin_1991/> have been proposed to explain the enrichment. However, the atmosphere is depleted of radiogenic argon, a proxy for mantle degassing, suggesting an early shutdown of major magmatism.<ref name=Namiki_Solomon_1998/><ref name="O'Rurke_Korenaga_2015"/>

Studies have suggested that billions of years ago, Venus's atmosphere could have been much more like the one surrounding the early Earth, and that there may have been substantial quantities of liquid water on the surface.<ref name="Ernst 2022"/><ref name="Way Del Genio 2020 p."/><ref name="Way Del Genio Kiang Sohl 2016 pp. 8376–8383"/> After a period of 600 million to several billion years,<ref name="baas39_540"/> [[solar forcing]] from rising luminosity of the Sun and possibly [[Large igneous province|large volcanic resurfacing]] caused the evaporation of the original water and the current atmosphere.<ref name="Steigerwald 2022"/> A runaway greenhouse effect was created once a critical level of greenhouse gases (including water) was added to its atmosphere.<ref name="Kasting"/> Although the surface conditions on Venus are no longer hospitable to any Earth-like life that may have formed before this event, there is speculation on the possibility that life exists in the upper cloud layers of Venus, {{convert|50|km|mi|sigfig=1|abbr=on}} up from the surface, where the atmospheric conditions are the most Earth-like in the Solar System,<ref name="Tillman 2018"/> with temperatures ranging between {{convert|30|and|80|C|K C F|order=out}}, and the pressure and radiation being about the same as at Earth's surface, but with acidic clouds and the carbon dioxide air.<ref name=Mullen_2002/><ref name=Landis_2003/><ref name="Cockell1999"/> Venus's atmosphere could also have a potential thermal [[habitable zone]] at elevations of 54 to 48&nbsp;km, with lower elevations inhibiting [[cell growth]] and higher elevations exceeding evaporation temperature.<ref name="Patel Mason Nordheim Dartnell 2022 p=114796">{{cite journal |last1=Patel |first1=M.R. |last2=Mason |first2=J.P. |last3=Nordheim |first3=T.A. |last4=Dartnell |first4=L.R. |year=2022 |title=Constraints on a potential aerial biosphere on Venus: II. Ultraviolet radiation |url=https://oro.open.ac.uk/80021/9/80021VOR.pdf |journal=Icarus |publisher=Elsevier BV |volume=373 |page=114796 |bibcode=2022Icar..37314796P |doi=10.1016/j.icarus.2021.114796 |issn=0019-1035 |s2cid=244168415 |doi-access=free}}</ref><ref name="Herbst Banjac Atri Nordheim 2019 p=A15">{{cite journal |last1=Herbst |first1=Konstantin |last2=Banjac |first2=Saša |last3=Atri |first3=Dimitra |last4=Nordheim |first4=Tom A. |date=24 December 2019 |title=Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability |journal=Astronomy & Astrophysics |publisher=EDP Sciences |volume=633 |page=A15 |arxiv=1911.12788 |bibcode=2020A&A...633A..15H |doi=10.1051/0004-6361/201936968 |issn=0004-6361 |s2cid=208513344}}</ref> The putative detection of an [[absorption line]] of [[phosphine]] in Venus's atmosphere, with no known pathway for abiotic production, led to speculation in September 2020 that there could be extant life currently present in the atmosphere.<ref name=Drake_2020/><ref name=Greaves_et_al_2020/> Later research attributed the spectroscopic signal that was interpreted as phosphine to sulphur dioxide,<ref name=Lincowski_et_al_2021/> or found that in fact there was no absorption line.<ref name=Beall_2020/><ref name=Snellan_et_al_2020/>

[[File:11214 2023 956 Fig6 HTML.webp|thumb|Types of cloud layers, as well as temperature and pressure change by altitude in the atmosphere]]

[[Thermal inertia]] and the transfer of heat by winds in the lower atmosphere mean that the temperature of Venus's surface does not vary significantly between the planet's two hemispheres, those facing and not facing the Sun, despite Venus's slow rotation. Winds at the surface are slow, moving at a few kilometres per hour, but because of the high density of the atmosphere at the surface, they exert a significant amount of force against obstructions, and transport dust and small stones across the surface. This alone would make it difficult for a human to walk through, even without the heat, pressure, and lack of oxygen.<ref name=Moshkin_et_al_1979/>

Above the dense {{chem2|CO2}} layer are thick clouds, consisting mainly of [[sulfuric acid]], which is formed by sulphur dioxide and water through a chemical reaction resulting in sulfuric acid hydrate. Additionally, the clouds consist of approximately 1% [[ferric chloride]].<ref name="kras006"/><ref name=Krasnopolsky_2006/> Other possible constituents of the cloud particles are [[ferric sulfate]], [[aluminium chloride]] and [[phosphoric anhydride]]. Clouds at different levels have different compositions and particle size distributions.<ref name="kras006"/> These clouds reflect, similar to thick cloud cover on Earth,{{Citation needed|date=September 2024|reason=This was previously supported by a generally unreliable source}} about 70% of the sunlight that falls on them back into space,<ref name="Davis 2021"/> and since they cover the whole planet they prevent visual observation of Venus's surface. The permanent cloud cover means that although Venus is closer than Earth to the Sun, it receives less sunlight on the ground, with only 10% of the received sunlight reaching the surface,<ref name="ESA Blog Navigator – Navigator page for active ESA blogs 2012"/> resulting in average daytime levels of illumination at the surface of 14,000 [[lux]], comparable to that on Earth "in the daytime with overcast clouds".<ref name=sci_news_1976/> Strong {{convert|300|km/h|mph|round=5|abbr=on}} winds at the cloud tops go around Venus about every four to five Earth days.<ref name=Rossow_et_al_1990/> Winds on Venus move at up to 60 times the speed of its rotation, whereas Earth's fastest winds are only 10–20% rotation speed.<ref name="science328"/>

The surface of Venus is effectively [[isothermal]]; it retains a constant temperature not only between the two hemispheres but between the equator and the poles.<ref name="fact"/><ref name=Lorenz_et_al_2001/> Venus's minute [[axial tilt]]—less than 3°, compared to 23° on Earth—also minimizes seasonal temperature variation.<ref name=NASA_Seasons/> Altitude is one of the few factors that affect Venusian temperatures. The highest point on Venus, [[Maxwell Montes]], is therefore the coolest point on Venus, with a temperature of about {{convert|380|C|K C F|order=out|round=5}} and an atmospheric pressure of about {{convert|45|bar|MPa|abbr=on|order=flip}}.<ref name="Basilevsky_2003"/><ref name="McGill_2010"/> In 1995, the [[Magellan (spacecraft)|''Magellan'' spacecraft]] imaged a highly reflective substance at the tops of the highest mountain peaks, a "[[Venus snow]]" that bore a strong resemblance to terrestrial snow. This substance likely formed from a similar process to snow, albeit at a far higher temperature. Too volatile to condense on the surface, it rose in gaseous form to higher elevations, where it is cooler and could precipitate. The identity of this substance is not known with certainty, but speculation has ranged from elemental [[tellurium]] to lead sulfide ([[galena]]).<ref name=Otten_2004/>

Although Venus has no seasons, in 2019 astronomers identified a cyclical variation in sunlight absorption by the atmosphere, possibly caused by opaque, absorbing particles suspended in the upper clouds. The variation causes observed changes in the speed of Venus's zonal winds and appears to rise and fall in time with the Sun's 11-year [[sunspot cycle]].<ref name="TAJ-20190826"/>

The existence of lightning in the atmosphere of Venus has been controversial<ref name="Lorentz_2018"/> since the first suspected bursts were detected by the Soviet [[Venera|Venera probes]].<ref name="Kranopol'skii_1980"/><ref name="Russell, Philips"/><ref name=Venera_12/> In 2006–07, ''[[Venus Express]]'' clearly detected [[Electromagnetic electron wave#R wave and L wave|whistler mode waves]], the signatures of lightning. Their [[wikt:intermittent|intermittent]] appearance indicates a pattern associated with weather activity. According to these measurements, the lightning rate is at least half that on Earth,<ref name="Russell_2007"/> however other instruments have not detected lightning at all.<ref name="Lorentz_2018" /> The origin of any lightning remains unclear, but could originate from clouds or [[Volcanism on Venus|Venusian volcanoes]].

In 2007, ''Venus Express'' discovered that a huge double [[Polar vortex|atmospheric polar vortex]] exists at the south pole.<ref name=Hand_2007/><ref name=BBC_2007_11_28/> ''Venus Express'' discovered, in 2011, that an [[ozone]] layer exists high in the atmosphere of Venus.<ref name="esaozone"/> On 29 January 2013, [[ESA]] scientists reported that the [[ionosphere]] of Venus streams outwards in a manner similar to "the ion tail seen streaming from a [[comet]] under similar conditions."<ref name="ESA-20130129"/><ref name="Space-20130130"/>

In December 2015, and to a lesser extent in April and May 2016, researchers working on Japan's ''Akatsuki'' mission observed bow-shaped objects in the atmosphere of Venus. This was considered direct evidence of the existence of perhaps the largest stationary [[gravity wave]]s in the solar system.<ref name=Fukuhara_et_al_2017/><ref name=Rincon_2017/><ref name=Chang_2017/>

== Orbit and rotation ==
{{Main|Orbit of Venus}}
[[File:Solar system orrery inner planets.gif|alt=Mars circling the Sun further and slower than Earth|thumb|Venus is the second planet from the Sun, making a full orbit in about 224 days]]

Venus orbits the Sun at an average distance of about {{convert|0.72|AU|e6km+e6mi|abbr=unit|lk=on}}, and completes an orbit every 224.7 days. Although all planetary [[orbit]]s are [[ellipse|elliptical]], Venus's orbit is currently the closest to circular, with an [[Orbital eccentricity|eccentricity]] of less than 0.01.<ref name="fact" /> Simulations of the early solar system orbital dynamics have shown that the eccentricity of the Venus orbit may have been substantially larger in the past, reaching values as high as 0.31 and possibly impacting early climate evolution.<ref name="psj_1_42"/>

[[File:11214 2023 956 Fig7 HTML.webp|thumb|Venus and its rotation in respect to its revolution.]]

All planets in the Solar System orbit the Sun in an [[anticlockwise]] direction as viewed from above Earth's north pole. Most planets rotate on their axes in an anticlockwise direction, but Venus rotates clockwise in [[retrograde rotation]] once every 243 Earth days—the slowest rotation of any planet. This Venusian [[sidereal day]] lasts therefore longer than a Venusian year (243 versus 224.7 Earth days). Slowed by its strong atmospheric current the length of the day also [[Day length fluctuations|fluctuates]] by up to 20 minutes.<ref name="EarthSky Updates on your cosmos and world 2021">{{cite web | title=The length of a day on Venus is always changing – Space | website=EarthSky | date=5 May 2021 | url=https://earthsky.org/space/venus-length-of-day-spin-rate-axial-tilt-radio-waves/ | access-date=28 April 2023 | archive-date=28 April 2023 | archive-url=https://web.archive.org/web/20230428232110/https://earthsky.org/space/venus-length-of-day-spin-rate-axial-tilt-radio-waves/ | url-status=live }}</ref> Venus's equator rotates at {{convert|6.52|km/h|mph|abbr=on}}, whereas Earth's rotates at {{convert|1674.4|km/h|mph|abbr=on}}.{{refn|group=note
|The equatorial speed of Earth is given as both about 1674.4{{spaces}}km/h and 1669.8{{spaces}}km/h by reliable sources. The simplest way to determine the correct figure is to multiply Earth's radius of {{nowrap|{{val|6378137}} m}} (WGS84) and Earth's angular speed, {{nowrap|{{val|7.2921150}}{{e|−5}} rad/s}},<ref name=IERS/> yielding {{nowrap|465.1011 m/s {{=}}}} 1674.364{{spaces}}km/h. The incorrect figure of 1669.8{{spaces}}km/h is obtained by dividing Earth's equatorial circumference by 24{{spaces}}h. But the correct speed must be relative to inertial space, so the stellar day of {{nowrap|{{val|86164.098903691}} s/3600 {{=}}}} {{nowrap|{{val|23.934472}} h}} {{nowrap|(23 h 56 m 4.0989 s)}} must be used.<ref name=stellar/> Thus {{nowrap|{{sfrac|2π(6378.137&nbsp;km)|23.934472 h}} {{=}}}} 1674.364{{spaces}}km/h.<ref name=CASTOR/>
}}<ref name=Bakich_2000/> Venus's rotation period measured with ''Magellan'' spacecraft data over a 500-day period is smaller than the rotation period measured during the 16-year period between the Magellan spacecraft and ''Venus Express'' visits, with a difference of about 6.5{{spaces}}minutes.<ref name="slowing spin"/> Because of the retrograde rotation, the length of a [[solar day]] on Venus is significantly shorter than the sidereal day, at 116.75 Earth days (making the Venusian solar day shorter than [[Mercury (planet)|Mercury]]'s 176 Earth days &mdash; the 116-day figure is close to the average number of days it takes Mercury to slip underneath the Earth in its orbit [the number of days of Mercury's synodic 
orbital period]).<ref name="planetary-facts"/> One Venusian year is about 1.92{{spaces}}Venusian solar days.<ref name="compare"/> To an observer on the surface of Venus, the Sun would rise in [[Poles of astronomical bodies|the west]] and set in the east,<ref name="compare" /> although Venus's opaque clouds prevent observing the Sun from the planet's surface.<ref name=Brunier_2002/>

Venus may have formed from the [[solar nebula]] with a different rotation period and obliquity, reaching its current state because of chaotic spin changes caused by planetary perturbations and [[tide|tidal]] effects on its dense atmosphere, a change that would have occurred over the course of billions of years. The rotation period of Venus may represent an equilibrium state between tidal locking to the Sun's gravitation, which tends to slow rotation, and an atmospheric tide created by solar heating of the thick Venusian atmosphere.<ref name=Correia_et_al_2003/><ref name=Laskar_De_Surgy_2003/> The 584-day average interval between successive close approaches to Earth is almost exactly equal to 5{{spaces}}Venusian solar days (5.001444 to be precise),<ref name=Gold_Soter_1969/> but the hypothesis of a spin-orbit resonance with Earth has been discounted.<ref name="apj2_230_L123"/>

Venus has no natural satellites.<ref name="icarus202"/> It has several [[trojan asteroid]]s: the [[quasi-satellite]] {{mpl|524522 Zoozve}}<ref name=Mikkola_et_al_2004/><ref name=Carlos_De_la_Fuente_Marcos_2012/> and two other temporary trojans, {{mpl-|322756|2001 CK|32}} and {{mpl|2012 XE|133}}.<ref name="dynamics"/> In the 17th century, [[Giovanni Cassini]] reported a moon orbiting Venus, which was named [[Neith (hypothetical moon)|Neith]] and numerous sightings were reported over the following {{val|200|u=years}}, but most were determined to be stars in the vicinity. Alex Alemi's and [[David J. Stevenson|David Stevenson]]'s 2006 study of models of the early Solar System at the [[California Institute of Technology]] shows Venus likely had at least one moon created by a huge [[impact event]] billions of years ago.<ref name=Musser_2006/> About 10{{spaces}}million{{spaces}}years later, according to the study, another impact reversed the planet's spin direction and the resulting [[tidal deceleration]] caused the Venusian moon gradually to spiral inward until it collided with Venus.<ref name=Tytell_2006/> If later impacts created moons, these were removed in the same way. An alternative explanation for the lack of satellites is the effect of strong solar tides, which can destabilize large satellites orbiting the inner terrestrial planets.<ref name="icarus202" />

The orbital space of Venus has a [[interplanetary dust#Rings of dust|dust ring-cloud]],<ref name="Frazier 2021"/> with a suspected origin either from Venus–trailing asteroids,<ref name="Garner 2019"/> interplanetary dust migrating in waves, or the remains of the Solar System's original [[circumstellar disc]] that formed the [[planetary system]].<ref name="Rehm 2021"/>

=== Orbit in respect to Earth ===
[[File:Venus pentagram.png|thumb|upright|Earth is positioned at the centre of the diagram, and the curve represents the direction and distance of Venus as a function of time.|alt=A complex, spiral, floral pattern with five loops encircling the middle]]

Earth and Venus have a near [[orbital resonance]] of 13:8 (Earth orbits eight times for every 13 orbits of Venus).<ref name="Bazsó">{{cite journal |last1=Bazsó |first1=A. |last2=Eybl |first2=V. |last3=Dvorak |first3=R. |last4=Pilat-Lohinger |first4=E. |last5=Lhotka |first5=C. |year=2010 |title=A survey of near-mean-motion resonances between Venus and Earth |journal=[[Celestial Mechanics and Dynamical Astronomy]] |volume=107 |issue=1 |pages=63–76 |arxiv=0911.2357 |bibcode=2010CeMDA.107...63B |doi=10.1007/s10569-010-9266-6|s2cid=117795811 }}</ref>
Therefore, they approach each other and reach [[inferior conjunction]] in [[synodic period]]s of 584 days, on average.<ref name="fact" /> The path that Venus makes in relation to Earth viewed geocentrically draws a [[Pentagram#Pentagram of Venus|pentagram]] over five synodic periods, shifting every period by 144°. This pentagram of Venus is sometimes referred to as the petals of Venus due to the path's visual similarity to a flower.<ref name=Ottewel_2022/>

When Venus lies between Earth and the Sun in [[Conjunction (astronomy)#Superior and inferior|inferior]] conjunction, it makes the closest approach to Earth of any planet at an average distance of {{convert|41|e6km|e6mi|abbr=unit}}.<ref name="fact" />{{refn|group=note
|It is important to be clear about the meaning of "closeness". In the astronomical literature, the term "closest planets" often refers to the two planets that approach each other the most closely. In other words, the orbits of the two planets approach each other most closely. However, this does not mean that the two planets are closest over time. Essentially because Mercury is closer to the Sun than Venus, Mercury spends more time in proximity to Earth; it could, therefore, be said that Mercury is the planet that is "closest to Earth when averaged over time". However, using this time-average definition of "closeness", it turns out that Mercury is the closest planet to ''all'' other planets in the solar system. For that reason, arguably, the proximity-definition is not particularly helpful. An episode of the BBC Radio 4 programme "More or Less" explains the different notions of proximity well.<ref name="MoreOrLess" />
}}<ref name="MoreOrLess"/>
Because of the [[Milankovitch cycles#Orbital eccentricity|decreasing eccentricity of Earth's orbit]], the minimum distances will become greater over tens of thousands of years. From the year{{spaces}}1 to 5383, there are 526 approaches less than {{convert|40|e6km|e6mi|abbr=unit}}; then, there are none for about 60,158 years.<ref name=Solex11/>

While Venus approaches Earth the closest, Mercury is more often the closest to Earth of all planets.<ref name="AIP Publishing 2019 p."/><ref>{{cite magazine |title= Venus is not Earth's closest neighbour {{!}} Calculations and simulations confirm that on average, Mercury is the nearest planet to Earth-and to every other planet in the solar system. |magazine=Physics Today |doi=10.1063/PT.6.3.20190312a |first1=Tom |last1=Stockman |first2=Gabriel |last2=Monroe |first3=Samuel |last3=Cordner |date=2019 |publisher=American Institute of Physics}}</ref> Venus has the lowest [[gravitational potential]] difference to Earth than any other planet, needing the [[Delta-v budget|lowest delta-v]] to transfer between them.<ref name="Petropoulos Longuski Bonfiglio 2000 pp. 776–783"/><ref name="Taylor 2020"/>

Tidally Venus exerts the third strongest [[tidal force]] on Earth, after the Moon and the Sun, though significantly less.<ref name="Science Mission Directorate 2000">{{cite web | title=Interplanetary Low Tide | website=Science Mission Directorate | date=3 May 2000 | url=https://science.nasa.gov/science-news/science-at-nasa/2000/ast04may_1m | access-date=25 June 2023 | archive-date=4 June 2023 | archive-url=https://web.archive.org/web/20230604014510/https://science.nasa.gov/science-news/science-at-nasa/2000/ast04may_1m  }}</ref>

== Observability ==
[[File:Venus-pacific-levelled.jpg|thumb|alt=A photograph of the night sky taken from the seashore. A glimmer of sunlight is on the horizon. There are many stars visible. Venus is at the centre, much brighter than any of the stars, and its light can be seen reflected in the ocean.|Venus, pictured centre-right, is always brighter than all other planets or stars at their maximal brightness, as seen from Earth. Jupiter is visible at the top of the image.]]

To the [[naked eye]], Venus appears as a white point of light brighter than any other planet or star (apart from the Sun).<ref name=Dickinson_1998/> The planet's mean [[apparent magnitude]] is −4.14 with a standard deviation of 0.31.<ref name="Mallama_and_Hilton" /> The brightest magnitude occurs during the crescent phase about one month before or after an inferior conjunction. Venus fades to about magnitude −3 when it is backlit by the Sun.<ref name="MallamaSky" /> The planet is bright enough to be seen in broad daylight,<ref name=Flanders_2011/> but is more easily visible when the Sun is low on the horizon or setting. As an [[inferior planet]], it always lies within about 47° of the [[Sun]].<ref name="ephemeris"/>

Venus "overtakes" Earth every 584 days as it orbits the Sun.<ref name="fact" /> As it does so, it changes from the "Evening Star", visible after sunset, to the "Morning Star", visible before sunrise. Although Mercury, the other inferior planet, reaches a maximum elongation of only 28° and is often difficult to discern in twilight, Venus is hard to miss when it is at its brightest. Its greater maximum elongation means it is visible in dark skies long after sunset. As the brightest point-like object in the sky, Venus is a commonly misreported "[[unidentified flying object]]".<ref name=ASP_2021/>

=== Phases ===
{{Main|Phases of Venus}}
[[File:Phases Venus.jpg|thumb|The phases of Venus and evolution of its apparent diameter|alt=Diagram illustrating the phases of Venus]]

As it orbits the Sun, Venus displays [[phases of Venus|phases]] like those of the [[Moon]] in a [[optical telescope|telescopic]] view. The planet appears as a small and "full" disc when it is on the opposite side of the Sun (at superior [[conjunction (astronomy)|conjunction]]). Venus shows a larger disc and "quarter phase" at its maximum [[Elongation (astronomy)|elongation]]s from the Sun, and appears at its brightest in the night sky. The planet presents a much larger thin "crescent" in telescopic views as it passes along the near side between Earth and the Sun. Venus displays its largest size and "new phase" when it is between Earth and the Sun (at inferior conjunction). Its atmosphere is visible through telescopes by the halo of sunlight refracted around it.<ref name="ephemeris" /> The phases are clearly visible in a 4" telescope.<ref>{{Cite web |last=Lavender |first=Gemma |date=26 March 2023 |title=What equipment do you need to see and photograph the planets |url=https://www.space.com/what-equipment-do-you-need-to-see-and-photograph-the-planets |access-date=5 June 2024 |website=Space.com |language=en}}</ref> Although naked eye visibility of Venus's phases is disputed, records exist of observations of its crescent.<ref name="Goines_1995" />

=== Daylight apparitions ===
[[File:Lunar Occultation of Venus (NHQ201512070001).jpg|alt=venus next to a crescent moon in the blue daytime sky|thumb|Venus is often visible to the naked eye in daytime, as seen just prior to the lunar occultation of 7 December 2015]]
When Venus is sufficiently bright with enough angular distance from the sun, it is easily observed in a clear daytime sky with the naked eye, though most people do not know to look for it.<ref>{{Cite web |title=Viewing Venus in Broad Daylight |url=https://www.fourmilab.ch/images/venus_daytime/ |access-date=17 July 2023 |website=www.fourmilab.ch |archive-date=15 November 2021 |archive-url=https://web.archive.org/web/20211115012816/https://www.fourmilab.ch/images/venus_daytime/ |url-status=live }}</ref> Astronomer [[Edmund Halley]] calculated its maximum naked eye brightness in 1716, when many Londoners were alarmed by its appearance in the daytime. French emperor [[Napoleon Bonaparte]] once witnessed a daytime apparition of the planet while at a reception in [[Luxembourg]].<ref name="Chatfield_2015" /> Another historical daytime observation of the planet took place during the inauguration of the American president [[Abraham Lincoln]] in Washington, D.C., on 4{{spaces}}March 1865.<ref name="Gaherty_2012" />

=== Transits ===
{{Main|Transit of Venus}}
[[File:Transit of Venus viewed in Wagga Wagga (2).jpg|alt=White disk with a small black dot projected on a screen|left|thumb|[[2012 transit of Venus]], projected to a white card by a [[telescope]]]]

A [[transit (astronomy)|transit]] of Venus is the appearance of Venus in front of the Sun, during [[inferior conjunction]]. Since the orbit of Venus is slightly inclined relative to Earth's orbit, most inferior conjunctions with Earth, which occur every [[synodic period]] of 1.6 years, do not produce a transit of Venus above Earth. Consequently, Venus transits above Earth only occur when an inferior conjunction takes place during some days of June or December, the time where the orbits of Venus and Earth cross a straight line with the Sun.<ref name="NASA 2004">{{cite web | title=2004 and 2012 Transits of Venus | website=NASA | date=8 June 2004 | url=https://eclipse.gsfc.nasa.gov/transit/venus0412.html#:~:text=Transits%20of%20Venus%20are%20only,121.5%2C%208%20and%20105.5%20years. | access-date=2 May 2023 | archive-date=2 May 2023 | archive-url=https://web.archive.org/web/20230502134029/https://eclipse.gsfc.nasa.gov/transit/venus0412.html#:~:text=Transits%20of%20Venus%20are%20only,121.5%2C%208%20and%20105.5%20years. | url-status=live }}</ref> This results in Venus transiting above Earth in a sequence of currently {{val|8|u=years}}, {{val|105.5|u=years}}, {{val|8|u=years}} and {{val|121.5|u=years}}, forming cycles of {{val|243|u=years}}.

Historically, transits of Venus were important, because they allowed astronomers to determine the size of the [[astronomical unit]], and hence the size of the Solar System as shown by [[Jeremiah Horrocks]] in [[Transit of Venus, 1639|1639 with the first known observation]] of a Venus transit (after history's first observed planetary [[Transit of Mercury|transit in 1631, of Mercury]]).<ref name=Kollerstrom_1998/>

Only seven Venus transits have been observed so far, since their occurrences were calculated in the 1621 by [[Johannes Kepler]]. [[Captain Cook]] sailed to [[Tahiti]] in 1768 to record the third observed transit of Venus, which subsequently resulted in the exploration of the east coast of Australia.<ref name=Hornsby_1771/><ref name=Woolley_1969/>

The latest pair was [[Transit of Venus, 2004|June 8, 2004]] and [[Transit of Venus, 2012|June 5–6, 2012]]. The transit could be watched live from many online outlets or observed locally with the right equipment and conditions.<ref name=Boyle_2016/> The preceding pair of transits occurred in [[Transit of Venus, 1874|December 1874]] and [[Transit of Venus, 1882|December 1882]].

The next transit will occur in December 2117 and December 2125.<ref name=Espenak_2004/>

=== Ashen light ===

A long-standing mystery of Venus observations is the so-called [[ashen light]]—an apparent weak illumination of its dark side, seen when the planet is in the crescent phase. The first claimed observation of ashen light was made in 1643, but the existence of the illumination has never been reliably confirmed. Observers have speculated it may result from electrical activity in the Venusian atmosphere, but it could be illusory, resulting from the physiological effect of observing a bright, crescent-shaped object.<ref name=Baum_2000/><ref name="Russell, Philips" /> The ashen light has often been sighted when Venus is in the evening sky, when the evening terminator of the planet is towards Earth.

==Observation and exploration history==
{{Main|Observations and explorations of Venus}}

===Early observation===
Venus is in Earth's sky bright enough to be visible [[Naked eye|without aid]], making it one of the [[classical planets]] that human cultures have known and identified throughout history, particularly for being the third brightest object in Earth's sky after the Sun and the Moon. Because the movements of Venus appear to be discontinuous (it disappears due to its proximity to the sun, for many days at a time, and then reappears on the other horizon), some cultures did not recognize Venus as a single entity;<ref name="Cooley"/> instead, they assumed it to be two separate stars on each horizon: the morning and evening star.<ref name=Cooley/> Nonetheless, a [[cylinder seal]] from the [[Jemdet Nasr period]] and the [[Venus tablet of Ammisaduqa]] from the [[First Babylonian dynasty]] indicate that the ancient Sumerians already knew that the morning and evening stars were the same celestial object.<ref name=Sachs_1974/><ref name=Cooley/><ref name=Hobson_2009/>

[[File:Venus Tablet of Ammisaduqa.jpg|thumb|Oldest known recording of Venus positions, of the [[Babylonia|Babylonian]] ''[[Venus tablet of Ammisaduqa]]'' (1600 BC).]]

In the Old [[Babylonia]]n period, the planet Venus was known as Ninsi'anna, and later as Dilbat.<ref>Enn Kasak, Raul Veede. Understanding Planets in Ancient Mesopotamia. Folklore Vol. 16. Mare Kõiva & Andres Kuperjanov, Eds. ISSN 1406-0957</ref> The name "Ninsi'anna" translates to "divine lady, illumination of heaven", which refers to Venus as the brightest visible "star". Earlier spellings of the name were written with the [[cuneiform]] sign si4 (= SU, meaning "to be red"), and the original meaning may have been "divine lady of the redness of heaven", in reference to the colour of the morning and evening sky.<ref name=Heimpel_1982/>

The Chinese historically referred to the morning Venus as "the Great White" ({{transliteration|zh|Tàibái}} {{lang|zh|太白}}) or "the Opener (Starter) of Brightness" ({{transliteration|zh|Qǐmíng}} {{lang|zh|啟明}}), and the evening Venus as "the Excellent West One" ({{transliteration|zh|Chánggēng}} {{lang|zh|長庚}}).<ref name=Needham_1959/>

The ancient Greeks initially believed Venus to be two separate stars: [[Phosphorus (morning star)|Phosphorus]], the morning star, and [[Hesperus]], the evening star. [[Pliny the Elder]] credited the realization that they were a single object to [[Pythagoras]] in the sixth century BC,<ref name=Pliny_1991/> while [[Diogenes Laërtius]] argued that [[Parmenides]] (early fifth century) was probably responsible for this discovery.<ref name=Berkert_1972/> Though they recognized Venus as a single object, the ancient Romans continued to designate the morning aspect of Venus as [[Lucifer]], literally "Light-Bringer", and the evening aspect as [[Hesperus|Vesper]],<ref name=Dobbin_2002/> both of which are literal translations of their traditional Greek names.

In the second century, in his astronomical treatise ''[[Almagest]]'', [[Ptolemy]] theorized that both Mercury and Venus were located between the Sun and the Earth. The 11th-century [[Samanid Empire|Persian]] astronomer [[Avicenna]] claimed to have observed a [[transit of Venus]] (although there is some doubt about it),<ref name="Goldstein"/> which later astronomers took as confirmation of Ptolemy's theory.<ref name=Enc_Irnica/> In the 12th century, the [[Al-Andalus|Andalusian]] astronomer [[Ibn Bajjah]] observed "two planets as black spots on the face of the Sun"; these were thought to be the transits of Venus and Mercury by 13th-century [[Maragheh observatory|Maragha]] astronomer [[Qotb al-Din Shirazi]], though this cannot be true as there were no Venus transits in Ibn Bajjah's lifetime.<ref name=Ansari_2002/>{{refn|group=note
|Several claims of transit observations made by mediaeval Islamic astronomers have been shown to be sunspots.<ref name="VaqueroVázquez2009"/> Avicenna did not record the date of his observation. There was a transit of Venus within his lifetime, on 24 May 1032, although it is questionable whether it would have been visible from his location.<ref name="Kennard"/>}}

[[File:Dresden Codex p09.jpg|thumb|left|upright|The [[Pre-Columbian era|Pre-Columbian]] Mayan ''[[Dresden Codex]]'', which calculates appearances of Venus.]]

===Venus and early modern astronomy===
{{multiple image
|footer=In 1610 [[Galileo Galilei]] observed with his telescope that [[Phases of Venus|Venus showed phases]], despite remaining near the Sun in Earth's sky (first image). This proved that it orbits the [[Sun]] and not Earth, as predicted by [[Copernicus]]'s [[heliocentric model]] and disproved Ptolemy's [[geocentric model]] (second image).
|align=right
|image1 = Phases-of-Venus2.svg|
|image2 = Phases-of-Venus-Geocentric.svg|}}

When the Italian physicist [[Galileo Galilei]] first observed the planet with a telescope in the early 17th century, he found it showed [[planetary phase|phases]] like the Moon, varying from crescent to gibbous to full and vice versa. When Venus is furthest from the Sun in the sky, it shows a [[Elongation (astronomy)|half-lit phase]], and when it is closest to the Sun in the sky, it shows as a crescent or full phase. This could be possible only if Venus orbited the Sun, and this was among the first observations to clearly contradict the Ptolemaic [[geocentric model]] that the Solar System was concentric and centred on Earth.<ref name="palmieri"/><ref name="Fegley"/>

The [[1639 transit of Venus]] was accurately predicted by [[Jeremiah Horrocks]] and observed by him and his friend, [[William Crabtree]], at each of their respective homes, on 4{{spaces}}December 1639 (24 November under the [[Julian calendar]] in use at that time).<ref name="Kollerstrom"/>

[[File:Lavender - Jeremiah Horrocks (1618–1641).jpg|thumb|[[William Richard Lavender]], ''Jeremiah Horrocks (1618–1641)'' (1903), [[Astley Hall, Chorley|Astley Hall Museum and Art Gallery]]]]

The [[atmosphere of Venus]] was discovered in 1761 by Russian polymath [[Mikhail Lomonosov]].<ref name="Marov2004"/><ref name=Britannica/> Venus's atmosphere was observed in 1790 by German astronomer [[Johann Schröter]]. Schröter found when the planet was a thin crescent, the cusps extended through more than 180°. He correctly surmised this was due to [[scattering]] of sunlight in a dense atmosphere. Later, American astronomer [[Chester Smith Lyman]] observed a complete ring around the dark side of the planet when it was at [[inferior conjunction]], providing further evidence for an atmosphere.<ref name=Russell_1899/> The atmosphere complicated efforts to determine a rotation period for the planet, and observers such as Italian-born astronomer [[Giovanni Cassini]] and Schröter incorrectly estimated periods of about {{val|24|u=hours}} from the motions of markings on the planet's apparent surface.<ref name=Hussey_1832/>

[[File:Venus Drawing.jpg|thumb|left|The "[[black drop effect]]" as recorded during the 1769 transit|alt=A hand-drawn sequence of images showing Venus passing over the edge of the Sun's disk, leaving an illusory drop of shadow behind]]

===Early 20th century advances===
Little more was discovered about Venus until the 20th century. Its almost featureless disc gave no hint what its surface might be like, and it was only with the development of [[astronomical spectroscopy|spectroscopic]] and [[ultraviolet]] observations that more of its secrets were revealed.

Spectroscopic observations in the 1900s gave the first clues about the Venusian rotation. [[Vesto Slipher]] tried to measure the [[Doppler shift]] of light from Venus, but found he could not detect any rotation. He surmised the planet must have a much longer [[rotation period]] than had previously been thought.<ref name=Slipher_1903/>

The first ultraviolet observations were carried out in the 1920s, when [[Frank E. Ross]] found that [[Ultraviolet photography|ultraviolet photographs]] revealed considerable detail that was absent in visible and [[infrared]] radiation. He suggested this was due to a dense, yellow lower atmosphere with high [[cirrus cloud]]s above it.<ref name=Ross_1928/>

It had been noted that Venus had no discernible [[oblate spheroid|oblateness]] in its disk, suggesting a slow rotation, and some astronomers concluded based on this that it was [[tidally locked]] like Mercury was believed to be at the time; but other researchers had detected a significant quantity of heat coming from the planet's nightside, suggesting a quick rotation (a high surface temperature was not suspected at the time), confusing the issue.<ref name=Martz_1934/> Later work in the 1950s showed the rotation was retrograde.

===Space age===
{{Further|List of missions to Venus}}
Humanity's first [[interplanetary spaceflight]] was achieved in 1961 with the [[Uncrewed spacecraft|robotic space probe]] ''[[Venera 1]]'' of the Soviet [[Venera]] programme flying to Venus, but it lost contact en route.<ref name="mitchell_1"/>

The first successful interplanetary mission, also to Venus, was ''[[Mariner 2]]'' of the United States' [[Mariner program]]me, passing on 14 December 1962 at {{convert|34833|km|mi|abbr=on}} above the surface of Venus and gathering data on the planet's atmosphere.<ref name=Mayer_et_al_1958/><ref name=NASA_1962/>

Additionally [[Radar astronomy|radar observations]] of Venus were first carried out in the 1960s, and provided the first measurements of the rotation period, which were close to the actual value.<ref name=Goldstein_Carpenter_1963/>

''[[Venera 3]]'', launched in 1966, became humanity's first probe and lander to reach and impact another celestial body other than the Moon, but could not return data as it crashed into the surface of Venus. In 1967, ''[[Venera 4]]'' was launched and successfully deployed science experiments in the Venusian atmosphere before impacting. ''Venera 4'' showed the surface temperature was hotter than ''Mariner 2'' had calculated, at almost {{cvt|500|C|||}}, determined that the atmosphere was 95% carbon dioxide ({{chem|C|O|2}}), and discovered that Venus's atmosphere was considerably denser than ''Venera 4''{{'s}} designers had anticipated.<ref name="mitchell_2"/>

In an early example of space cooperation the data of ''Venera 4'' was joined with the 1967 ''[[Mariner 5]]'' data, analysed by a combined Soviet–American science team in a series of colloquia over the following year.<ref name=COSPAR_Group_VII_1969/>

On 15 December 1970, ''[[Venera 7]]'' became the first spacecraft to [[Landings on other planets|soft land on another planet]] and the first to transmit data from there back to Earth.<ref name=Time_1971/>

In 1974, ''[[Mariner 10]]'' swung by Venus to bend its path towards Mercury and took ultraviolet photographs of the clouds, revealing the extraordinarily high wind speeds in the Venusian atmosphere. This was the first interplanetary [[gravity assist]] ever used, a technique which would be used by later probes.

Radar observations in the 1970s revealed details of the Venusian surface for the first time. Pulses of radio waves were beamed at the planet using the {{convert|300|m|ft|sigfig=1|abbr=on}} radio telescope at [[Arecibo Observatory]], and the echoes revealed two highly reflective regions, designated the [[Alpha Regio|Alpha]] and [[Beta Regio|Beta]] regions. The observations revealed a bright region attributed to mountains, which was called [[Maxwell Montes]].<ref name=Campbell_et_al_1976/> These three features are now the only ones on Venus that do not have female names.<ref name="jpl-magellan"/>

[[File:Foto de Venera 9.png|thumb|First view and first clear 180-degree panorama of Venus's surface as well as any other planet than Earth (1975, Soviet ''[[Venera&nbsp;9]]'' lander). Black-and-white image of barren, black, slate-like rocks against a flat sky. The ground and the probe are the focus.|upright=2]]

In 1975, the Soviet ''[[Venera 9]]'' and ''[[Venera 10|10]]'' landers transmitted the first images from the surface of Venus, which were in black and white. NASA obtained additional data with the [[Pioneer Venus project]], consisting of two separate missions:<ref name=Colin_Hall_1977/> the [[Pioneer Venus Multiprobe]] and [[Pioneer Venus Orbiter]], orbiting Venus between 1978 and 1992.<ref name=Williams_2005/> In 1982 the first colour images of the surface were obtained with the Soviet ''[[Venera&nbsp;13]]'' and ''[[Venera 14|14]]'' landers. After ''[[Venera 15]]'' and ''[[Venera 16|16]]'' operated between 1983 and 1984 in orbit, conducting detailed mapping of 25% of Venus's terrain (from the north pole to 30°N latitude), the Soviet Venera programme came to a close.<ref name=Greeley_Batson_2007/>

[[File:Russian "Vega" balloon mission to Venus on display at the Udvar-Hazy museum.jpg|thumb|left|[[Vega programme|Vega balloon probe]] on display at the [[Steven F. Udvar-Hazy Center|Udvar-Hazy Center]] of the [[Smithsonian Institution]]]]

In 1985 the Soviet [[Vega programme]] with its ''[[Vega 1]]'' and ''[[Vega 2]]'' missions carried the last entry probes and carried the first ever extraterrestrial [[aerobot]]s for the first time achieving atmospheric flight outside Earth by employing inflatable balloons.

Between 1990 and 1994, ''[[Magellan (spacecraft)|Magellan]]'' operated in orbit until deorbiting, mapping the surface of Venus. Furthermore, probes like ''[[Galileo (spacecraft)|Galileo]]'' (1990),<ref name="PDS Atmospheres Node 1989">{{cite web | title=Welcome to the Galileo Orbiter Archive Page | website=PDS Atmospheres Node | date=18 October 1989 | url=https://pds-atmospheres.nmsu.edu/data_and_services/atmospheres_data/Galileo/galileo_orbiter.html | access-date=11 April 2023 | archive-date=11 April 2023 | archive-url=https://web.archive.org/web/20230411212904/https://pds-atmospheres.nmsu.edu/data_and_services/atmospheres_data/Galileo/galileo_orbiter.html | url-status=live }}</ref> ''[[Cassini–Huygens]]'' (1998/1999), and ''[[MESSENGER]]'' (2006/2007) visited Venus with flybys en route to other destinations.
In April 2006, ''[[Venus Express]]'', the first dedicated Venus mission by the [[European Space Agency]] (ESA), entered orbit around Venus. ''Venus Express'' provided unprecedented observation of Venus's atmosphere. ESA concluded the ''Venus Express'' mission in December 2014 deorbiting it in January 2015.<ref name=Howell_2014/>

In 2010, the first successful interplanetary [[solar sail]] spacecraft [[IKAROS]] travelled to Venus for a flyby.

Between 2015 and 2024 Japan's ''[[Akatsuki (spacecraft)|Akatsuki]]'' probe was active in orbit around Venus and [[BepiColombo]] performed flybys in 2020/2021.

[[File:Wispr 4thflyby.gif|thumb|[[WISPR]] of the [[Parker Solar Probe]] took this visible light footage of the nightside in 2021, showing the hot faintly glowing surface, and its [[Aphrodite Terra]] as large dark patch, through the clouds, which prohibit such observations on the dayside when they are illuminated.<ref>{{cite web |last1=Hatfield |first1=Miles |title=Parker Solar Probe Captures Visible Light Images of Venus' Surface |url=https://www.nasa.gov/feature/goddard/2022/sun/parker-solar-probe-captures-its-first-images-of-venus-surface-in-visible-light-confirmed |website=NASA |access-date=29 April 2022 |date=9 February 2022 |archive-date=14 April 2022 |archive-url=https://web.archive.org/web/20220414155959/https://www.nasa.gov/feature/goddard/2022/sun/parker-solar-probe-captures-its-first-images-of-venus-surface-in-visible-light-confirmed/ |url-status=live }}</ref><ref name="Geophysical Research Letters 2022">{{cite journal | journal=Geophysical Research Letters | last1=Wood | first1=B. E. | last2=Hess | first2=P. | last3=Lustig-Yaeger | first3=J. | last4=Gallagher | first4=B. | last5=Korwan | first5=D. | last6=Rich | first6=N. | last7=Stenborg | first7=G. | last8=Thernisien | first8=A. | last9=Qadri | first9=S. N. | last10=Santiago | first10=F. | last11=Peralta | first11=J. | last12=Arney | first12=G. N. | last13=Izenberg | first13=N. R. | last14=Vourlidas | first14=A. | last15=Linton | first15=M. G. | last16=Howard | first16=R. A. | last17= Raouafi | first17=N. E. | doi=10.1029/2021GL096302 | date=9 February 2022 | title=Parker Solar Probe Imaging of the Night Side of Venus | volume=49 | issue=3| pages=e2021GL096302 | pmid=35864851 | pmc=9286398 | bibcode=2022GeoRL..4996302W }}</ref>]]

===Active and future missions===
{{Further|List of missions to Venus#Future missions}}

Currently NASA's [[Parker Solar Probe]] and [[BepiColombo]] have been performing flybys at Venus.

Beside these flybys there are at the moment several [[List of missions to Venus|probes under development]] as well as multiple proposed missions still in their early conceptual stages.

Venus has been identified for future research as an important case for understanding:
* the origins of the solar system and Earth, and if systems and planets like ours are common or rare in the universe.
* how planetary bodies evolve from their primordial states to today's diverse objects.
* the development of conditions leading to habitable environments and life.<ref name="O'Rourke Wilson Borrelli Byrne 2023 p.">{{cite journal | last1=O'Rourke | first1=Joseph G. | last2=Wilson | first2=Colin F. | last3=Borrelli | first3=Madison E. | last4=Byrne | first4=Paul K. | last5=Dumoulin | first5=Caroline | last6=Ghail | first6=Richard | last7=Gülcher | first7=Anna J. P. | last8=Jacobson | first8=Seth A. | last9=Korablev | first9=Oleg | last10=Spohn | first10=Tilman | last11=Way | first11=M. J. | last12=Weller | first12=Matt | last13=Westall | first13=Frances | title=Venus, the Planet: Introduction to the Evolution of Earth's Sister Planet | journal=Space Science Reviews | publisher=Springer Science and Business Media LLC | volume=219 | issue=1 | year=2023 | issn=0038-6308 | doi=10.1007/s11214-023-00956-0 | page=10| bibcode=2023SSRv..219...10O | s2cid=256599851 | hdl=20.500.11850/598198 | hdl-access=free }}</ref>

[[File:Venus Life Finder Descent.png|thumb|upright=1.5|right|Diagram of [[Venus Life Finder]]'s probe's planned operations from atmospheric entry to surface impact, with a launch planned for 2025]]

==Search for life==
{{Main|Life on Venus}}

Speculation on the possibility of life on Venus's surface decreased significantly after the early 1960s when it became clear that conditions were extreme compared to those on Earth. Venus's extreme temperatures and atmospheric pressure make water-based life, as currently known, unlikely.

Some scientists have speculated that thermoacidophilic [[extremophile]] [[microorganism]]s might exist in the cooler, acidic upper layers of the Venusian [[Atmosphere of Venus|atmosphere]].<ref name=Clark_2003/><ref name=Redfern_2004/><ref name="Dartnell2015"/> Such speculations go back to 1967, when [[Carl Sagan]] and [[Harold J. Morowitz]] suggested in a ''[[Nature (journal)|Nature]]'' article that tiny objects detected in Venus's clouds might be organisms similar to Earth's bacteria (which are of approximately the same size):
:While the surface conditions of Venus make the hypothesis of life there implausible, the clouds of Venus are a different story altogether. As was pointed out some years ago, water, [[carbon dioxide]] and sunlight—the prerequisites for [[photosynthesis]]—are plentiful in the vicinity of the clouds.<ref name=Sagan_Morowitz_1967/>

In August 2019, astronomers led by Yeon Joo Lee reported that long-term pattern of absorbance and [[albedo]] changes in the atmosphere of the planet Venus caused by "unknown absorbers", which may be chemicals or even large colonies of microorganisms high up in the atmosphere of the planet, affect the climate.<ref name="TAJ-20190826"/> Their [[Light absorption|light absorbance]] is almost identical to that of micro-organisms in Earth's clouds. Similar conclusions have been reached by other studies.<ref name="ES-20190903"/>

In September 2020, a team of astronomers led by [[Jane Greaves]] from [[Cardiff University]] announced the likely detection of [[phosphine]], a gas not known to be produced by any known chemical processes on the Venusian surface or atmosphere, in the upper levels of the planet's clouds.<ref name=Bains_et_al_2021/><ref name=Greaves_et_al_2020/><ref name=Drake_2020/><ref name=Perkins_2020/><ref name=Seager_et_al_2020/> One proposed source for this phosphine is living organisms.<ref name="Sample1"/> The phosphine was detected at heights of at least {{convert|30|mi|km}} above the surface, and primarily at mid-latitudes with none detected at the poles. The discovery prompted [[NASA]] administrator [[Jim Bridenstine]] to publicly call for a new focus on the study of Venus, describing the phosphine find as "the most significant development yet in building the case for life off Earth".<ref name=Kooser_2020/><ref name=Bridenstine_2020/>

Subsequent analysis of the data-processing used to identify phosphine in the atmosphere of Venus has raised concerns that the detection-line may be an artefact. The use of a 12th-order polynomial fit may have amplified noise and generated a false reading (see [[Runge's phenomenon]]). Observations of the atmosphere of Venus at other parts of the electromagnetic spectrum in which a phosphine absorption line would be expected did not detect phosphine.<ref name="Plait1"/> By late October 2020, re-analysis of data with a proper subtraction of background did not show a [[statistically significant]] detection of phosphine.<ref name=Snellen_et_al_2020/><ref name=Thompson2020/><ref name=Cordiner_et_al_2021/>

Members of the team around Greaves, are working as part of a project by the [[MIT]] to send with the rocket company [[Rocket Lab]] the first private interplanetary space craft, to look for organics by entering the atmosphere of Venus with a [[Venus Life Finder|probe]], set to launch in January 2025.<ref name="Venus Cloud Life - MIT 2023">{{cite web | title=Rocket Lab Probe | website=Venus Cloud Life – MIT | date=7 March 2023 | url=https://venuscloudlife.com/small-mission/ | access-date=13 May 2023 | archive-date=8 February 2024 | archive-url=https://web.archive.org/web/20240208040505/https://venuscloudlife.com/small-mission/ | url-status=live }}</ref>

===Planetary protection===
The [[Committee on Space Research]] is a scientific organization established by the [[International Council for Science]]. Among their responsibilities is the development of recommendations for avoiding [[interplanetary contamination]]. For this purpose, space missions are categorized into five groups. Due to the harsh surface environment of Venus, Venus has been under the [[planetary protection]] category two.<ref name=NRC_2006/> This indicates that there is only a remote chance that spacecraft-borne contamination could compromise investigations.

==Human presence==
{{Main|List of missions to Venus}}
[[File:VenusLanderTopo.jpg|thumb|upright=1.5|Global topographic map of Venus, with all probe landings marked]]
Venus is the place of the first interplanetary human presence, mediated through robotic missions, with the first successful landings on another planet and extraterrestrial body other than the Moon. Currently in orbit is [[Akatsuki (spacecraft)|Akatsuki]], and other probes routinely use Venus for [[gravity assist]] manoeuvres capturing some data about Venus on the way.<ref name=Frazier_2021/>

The only nation that has sent [[Lander (spacecraft)|lander probes]] to the surface of Venus has been the Soviet Union,{{refn|group=note|The American [[Pioneer Venus Multiprobe]] has brought the only non-Soviet probes to enter the atmosphere, as [[atmospheric entry probe]]s only briefly signals were received from the surface.}} which has been used by Russian officials to call Venus a "Russian planet".<ref name="Kolirin1"/><ref name="Leman1"/>

=== Crewed flight ===
Studies of routes for [[crewed missions to Mars]] have since the 1960s proposed [[Opposition (astronomy)|opposition]] missions instead of direct [[Conjunction (astronomy)|conjunction]] missions with Venus [[gravity assist]] [[flyby (spaceflight)|flybys]], demonstrating that they should be quicker and safer missions to [[Mars]], with better return or abort flight windows, and less or the same amount of radiation exposure from the flight as direct Mars flights.<ref name="Rao 2020">{{cite web | last=Rao | first=Rahul | title=Astronauts bound for Mars should swing by Venus first, scientists say | website=Space.com | date=7 July 2020 | url=https://www.space.com/mars-astronauts-venus-flyby-idea.html | access-date=24 April 2023 | archive-date=24 April 2023 | archive-url=https://web.archive.org/web/20230424055519/https://www.space.com/mars-astronauts-venus-flyby-idea.html | url-status=live }}</ref><ref name="Izenberg McNutt Runyon Byrne 2021 pp. 100–104">{{cite journal | last1=Izenberg | first1=Noam R. | last2=McNutt | first2=Ralph L. | last3=Runyon | first3=Kirby D. | last4=Byrne | first4=Paul K. | last5=MacDonald | first5=Alexander | title=Venus Exploration in the New Human Spaceflight Age | journal=Acta Astronautica | publisher=Elsevier BV | volume=180 | year=2021 | issn=0094-5765 | doi=10.1016/j.actaastro.2020.12.020 | pages=100–104| bibcode=2021AcAau.180..100I | s2cid=219558707 | doi-access=free }}</ref>

Early in the space age the [[Soviet Union]] and the United States proposed the [[TMK]]-MAVR and [[Manned Venus flyby]] crewed flyby missions to Venus, though they were never realized.

=== Habitation ===
{{See also|Floating cities and islands in fiction#Venus|Colonization of Venus}}
[[File:NASA Cloud City on Venus.jpg|thumb|Artist's rendering of a NASA [[HAVOC|High Altitude Venus Operational Concept (HAVOC)]] crewed floating outpost on Venus]]

While the surface conditions of Venus are inhospitable, the atmospheric pressure, temperature, and solar and cosmic radiation 50&nbsp;km above the surface are similar to those at Earth's surface.<ref name="Herbst Banjac Atri Nordheim 2019 p=A15"/><ref name="Patel Mason Nordheim Dartnell 2022 p=114796"/> With this in mind, Soviet engineer [[Sergey Zhitomirskiy]] (Сергей Житомирский, 1929–2004) in 1971<ref name="Архив фантастики"/><ref name="Inner Solar System 2015"/> and NASA aerospace engineer [[Geoffrey A. Landis]] in 2003<ref name="Landis2003" /> suggested the use of [[aerostat]]s for crewed exploration and possibly for permanent "[[Floating cities and islands in fiction#Venus|floating cities]]" in the Venusian atmosphere, an alternative to the popular idea of living on [[planetary surface]]s such as [[Mars]].<ref name="Tickle 2015"/><ref name=Warmflash_2017/> Among the many engineering challenges for any human presence in the atmosphere of Venus are the corrosive amounts of [[sulfuric acid]] in the atmosphere.<ref name="Landis2003"/>

NASA's [[High Altitude Venus Operational Concept]] is a mission concept that proposed a crewed aerostat design.

==In culture==
{{Main|Venus in culture}}
Venus is a primary feature of the night sky, and so has been of remarkable importance in [[Venus (mythology)|mythology]], [[Planets in astrology#Venus|astrology]] and [[Venus in fiction|fiction]] throughout history and in different cultures.

[[File:Kudurru Melishipak Louvre Sb23 n02.jpg|thumb|The [[Octagram|eight-pointed star]] a symbol used in some cultures for Venus, and sometimes combined into a [[star and crescent]] arrangement. Here the eight pointed star is the [[Star of Ishtar]], the [[Babylonia]]n Venus goddess, alongside the [[solar symbol|solar disk]] of her brother [[Shamash]] and the [[crescent|crescent moon]] of their father [[Sin (mythology)|Sin]] on a [[kudurru|boundary stone]] of [[Meli-Shipak II]], dating to the twelfth century BC.]]

{{anchor|Inanna and Shukaletuda}}
Several hymns praise Inanna in her role as the goddess of the planet Venus.<ref name=Cooley/><ref name="Green1992"/><ref name="Nemet-Nejat"/> Theology professor Jeffrey Cooley has argued that, in many myths, Inanna's movements may correspond with the movements of the planet Venus in the sky.<ref name=Cooley/> The discontinuous movements of Venus relate to both mythology as well as Inanna's dual nature.<ref name=Cooley/> In ''Inanna's Descent to the Underworld'', unlike any other deity, Inanna is able to descend into the netherworld and return to the heavens. The planet Venus appears to make a similar descent, setting in the West and then rising again in the East.<ref name=Cooley/> An introductory hymn describes Inanna leaving the heavens and heading for ''Kur'', what could be presumed to be, the mountains, replicating the rising and setting of Inanna to the West.<ref name=Cooley/> In ''[[Inanna and Shukaletuda]]'' and ''[[Inanna's Descent into the Underworld]]'' appear to parallel the motion of the planet Venus.<ref name=Cooley/> In ''Inanna and Shukaletuda'', Shukaletuda is described as scanning the heavens in search of Inanna, possibly searching the eastern and western horizons.<ref name="Cooley2"/> In the same myth, while searching for her attacker, Inanna herself makes several movements that correspond with the movements of Venus in the sky.<ref name=Cooley/>

The [[Ancient Egypt]]ians and [[ancient Greeks]] possibly knew by the second millennium BC or at the latest by the [[Late Period of ancient Egypt|Late Period]], under [[mesopotamia]]n influence that the morning star and an evening star were one and the same.<ref name="Parker 1974"/><ref name="Quack 2019"/> The Egyptians knew the morning star as ''Tioumoutiri'' and the evening star as ''Ouaiti''.<ref name=Cattermole_Moore_1997/> They depicted Venus at first as a [[Phoenix (mythology)|phoenix]] or [[heron]] (see [[Bennu]]),<ref name="Parker 1974"/> calling it "the crosser" or "star with crosses",<ref name="Parker 1974"/> associating it with [[Osiris]], and later depicting it two-headed with human or falco heads, and associated it with [[Horus]],<ref name="Quack 2019"/> son of [[Isis]] (which during the even later [[Hellenistic period]] was together with [[Hathor]] identified with [[Aphrodite]]). The Greeks used the names ''[[Phosphoros|Phōsphoros]]'' (Φωσϕόρος), meaning "light-bringer" (whence the element [[phosphorus]]; alternately ''Ēōsphoros'' (Ἠωσϕόρος), meaning "dawn-bringer"), for the morning star, and ''[[Hesperos]]'' (Ἕσπερος), meaning "Western one", for the evening star,<ref name="EBLCM"/> both children of dawn [[Eos]] and therefore grandchildren of Aphrodite. Though by the Roman era they were recognized as one celestial object, known as "the star of [[Venus (mythology)|Venus]]", the traditional two Greek names continued to be used, though usually translated to Latin as [[Lucifer|''Lūcifer'']] and [[Hesperus|''Vesper'']].<ref name="EBLCM"/><ref name=Cicero/>

Classical poets such as [[Homer]], [[Sappho]], [[Ovid]] and [[Virgil]] spoke of the star and its light.<ref name=Atsma/> Poets such as [[William Blake]], [[Robert Frost]], [[Letitia Elizabeth Landon]], [[Alfred Lord Tennyson]] and [[William Wordsworth]] wrote odes to it.<ref name=Sobel_2005/>

In India, Shukra Graha ("the planet Shukra") is named after the powerful saint Shukra. ''[[Shukra]]'' which is used in Indian [[Vedic astrology]]<ref name="bhalla06"/> means "clear, pure" or "brightness, clearness" in [[Sanskrit]]. One of the nine [[Navagraha]], it is held to affect wealth, pleasure and reproduction; it was the son of [[Bhrgu]], preceptor of the Daityas, and guru of the Asuras.<ref name="behari_frawley03"/> The word ''Shukra'' is also associated with semen, or generation.

The English name of Venus was originally the [[Roman religion|ancient Roman]] name for it. Romans named Venus after [[Venus (goddess)|their goddess of love]], who in turn was based on the [[Ancient Greek religion|ancient Greek]] goddess of love [[Aphrodite]],<ref name="Getty"/> who was herself based on the similar [[Sumerian religion]] goddess [[Inanna]] (which is Ishtar in [[Akkadian religion]]), all of whom were associated with the planet.<ref name="Nemet-Nejat"/><ref name="Green1992"/> The [[Planetary hours|weekday of the planet]] and these goddesses is [[Friday]], named after the Germanic goddess [[Frigg]], who has been associated with the Roman goddess Venus.

Venus is known as Kejora in [[Indonesian language|Indonesian]] and [[Malaysian language|Malaysian]] [[Malay language|Malay]].

In Chinese the planet is called Jīn-xīng (金星), the golden planet of the [[Metal (Wu Xing)|metal element]]. Modern [[Chinese culture|Chinese]], [[Japanese culture|Japanese]], [[Korean culture|Korean]] and [[Culture of Vietnam|Vietnamese]] cultures refer to the planet literally as the "metal star" ({{lang|zh|金星}}), based on the [[Five elements (Chinese philosophy)|Five elements]].<ref name=De_Groot_1912/><ref name=Crump_1992/><ref name=Hulbert_1909/><ref name=VOER/>

The [[Maya civilisation|Maya]] considered Venus to be the most important celestial body after the Sun and Moon. They called it ''Chac ek'',<ref name="Volume 7 of Mayan studies"/> or ''Noh Ek''<nowiki>'</nowiki>, "the Great Star".<ref name="Milbrath"/> The cycles of Venus were important to their calendar and were described in some of their books such as ''[[Maya Codex of Mexico]]'' and ''[[Dresden Codex]].'' The ''[[Flag of Chile|Estrella Solitaria]]'' ("Lone Star") [[Flag of Chile]] depicts Venus.

===Modern culture===
{{See also|Venus in fiction}}
[[File:Van Gogh - Starry Night - Google Art Project.jpg|thumb|Venus is portrayed just to the right of the large cypress tree in [[Vincent van Gogh]]'s 1889 painting ''[[The Starry Night]]''.<ref name=Whitney_1986/><ref name=Boime_1984/>]]

The impenetrable Venusian cloud cover gave science fiction writers free rein to speculate on conditions at its surface; all the more so when early observations showed that not only was it similar in size to Earth, it possessed a substantial atmosphere. Closer to the Sun than Earth, the planet was often depicted as warmer, but still [[Planetary habitability|habitable]] by humans.<ref name="miller"/> The genre reached its peak between the 1930s and 1950s, at a time when science had revealed some aspects of Venus, but not yet the harsh reality of its surface conditions. Findings from the first missions to Venus showed reality to be quite different and brought this particular genre to an end.<ref name=Dick_2001/> As scientific knowledge of Venus advanced, science fiction authors tried to keep pace, particularly by conjecturing human attempts to [[Terraforming of Venus|terraform Venus]].<ref name=Seed_2005/>

=== Symbols ===
{{Main|Venus symbol}}
[[file:Venus symbol (planetary color).svg|frameless|left|80px]]

The symbol of a circle with a small cross beneath is the so-called [[Venus symbol]], gaining its name for being used as the [[astronomical symbol]] for Venus. The symbol is of [[ancient Greek]] origin, and represents more generally [[femininity]], adopted by biology as [[gender symbol]] for female,<ref name="Schott 2005 pp. 1509–1510"/><ref name="stearn1961"/><ref name="stearn"/> like the [[Mars symbol]] for male and sometimes the [[Mercury symbol]] for [[hermaphrodite]]. This gendered association of Venus and Mars has been used to pair them [[heteronormative]]ly, describing women and men stereotypically as being so different that they can be understood as coming from different planets, an understanding popularized in 1992 by the book titled ''[[Men Are from Mars, Women Are from Venus]]''.<ref name="Brammer 2020"/>

The Venus symbol was also used in Western [[alchemy]] representing the element [[copper]] (like the symbol of [[Mercury (planet)|Mercury]] is also the symbol of the [[element mercury]]),<ref name="stearn1961" /><ref name="stearn" /> and since polished copper has been used for mirrors from antiquity the symbol for Venus has sometimes been called Venus mirror, representing the mirror of the goddess, although this origin has been discredited as an unlikely origin.<ref name="stearn1961" /><ref name="stearn" />

Besides the Venus symbol, many other symbols have been associated with Venus, other common ones are the [[star and crescent|crescent or particularly the star]], as with the [[Star of Ishtar]].<ref>{{Cite book |last=Liungman |first=Carl G. |url=https://books.google.com/books?id=06ALKxX225IC |title=Symbols: Encyclopedia of Western Signs and Ideograms |date=2004 |publisher=HME Publishing |isbn=978-91-972705-0-2 |pages=228 |language=en}}</ref>

== See also ==
{{Portal|Solar System|Outer space|Astronomy}}
* [[Outline of Venus]]
* [[List of gravitationally rounded objects of the Solar System#Planets|Physical properties of planets in the Solar System]]
* [[Venus zone]]

== Notes ==

{{Reflist|group=note}}

== References ==

{{Reflist|refs=

<ref name=NASA_2015>{{cite web
 | title=Planets and Pluto: Physical Characteristics
 | url=http://ssd.jpl.nasa.gov/?planet_phys_par
 | publisher=[[NASA]] | date=5 November 2008
| access-date=26 August 2015 | archive-date=7 September 2006
| archive-url=https://web.archive.org/web/20060907215218/http://ssd.jpl.nasa.gov/?planet_phys_par
 | url-status=live }}</ref>

<ref name=Margot_et_al_2021>{{cite journal
 | title=Spin state and moment of inertia of Venus
 | display-authors=3 | last1=Margot | first1=Jean-Luc
 | last2=Campbell | first2=Donald B. | last3=Giorgini | first3=Jon D.
 | last4=Jao | first4=Joseph S. | last5=Snedeker | first5=Lawrence G.
 | last6=Ghigo | first6=Frank D. | last7=Bonsall | first7=Amber
 | journal=Nature Astronomy
 | date=29 April 2021 | volume=5 | issue=7 | pages=676–683
 | doi=10.1038/s41550-021-01339-7 | arxiv=2103.01504
 | bibcode=2021NatAs...5..676M | s2cid=232092194 }}</ref>

<ref name="American Chemical Society 2013">{{cite web
 | title=Atmospheres and Planetary Temperatures
 | website=American Chemical Society | date=18 July 2013
 | url=https://www.acs.org/climatescience/energybalance/planetarytemperatures.html
 | access-date=3 January 2023
 | archive-url=https://web.archive.org/web/20230127144936/https://www.acs.org/climatescience/energybalance/planetarytemperatures.html
 |archive-date=27 January 2023}}</ref>

<ref name="horizons">{{cite web
 | title=Horizons Web-Interface for Venus (Major Body=2)
 | last=Yeomans
 | first=Donald K.
 | url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272000-01-01%27&STOP_TIME=%272000-01-02%27&STEP_SIZE=%27200%20years%27&CENTER=%27@Sun%27&OUT_UNITS=%27AU-D%27
 | work=[[JPL Horizons On-Line Ephemeris System]]
 | access-date=30 November 2010
| archive-date=18 August 2023
| archive-url=https://web.archive.org/web/20230818120948/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272000-01-01%27&STOP_TIME=%272000-01-02%27&STEP_SIZE=%27200%20years%27&CENTER=%27%40Sun%27&OUT_UNITS=%27AU-D%27
 | url-status=live
 }}—Select "Ephemeris Type: Orbital Elements", "Time Span: 2000-01-01 12:00 to 2000-01-02". ("Target Body: Venus" and "Center: Sun" should be set to default.) Results are instantaneous [[osculating orbit|osculating]] values at the precise [[J2000]] epoch.</ref>

<ref name="radiation-levels">{{Cite journal | last1=Herbst | first1=K. | last2=Banjac | first2=S | last3=Atri D. | last4=Nordheim | first4=T. A | title=Revisiting the cosmic-ray induced Venusian radiation dose in the context of habitability | url=https://www.aanda.org/articles/aa/abs/2020/01/aa36968-19/aa36968-19.html | journal=Astronomy & Astrophysics | volume=633 | date=1 January 2020 | doi=10.1051/0004-6361/201936968 | arxiv=1911.12788 | bibcode=2020A&A...633A..15H | s2cid=208513344 | issn=0004-6361 | at=Fig. 6 | access-date=20 November 2021 | archive-date=5 December 2021 | archive-url=https://web.archive.org/web/20211205150049/https://www.aanda.org/articles/aa/abs/2020/01/aa36968-19/aa36968-19.html | url-status=live }}</ref>

<ref name=Lexico_Venusian>{{Cite encyclopedia
 | title=Venusian
 | dictionary=[[Lexico]] UK English Dictionary
 | publisher=[[Oxford University Press]]
 | url=http://www.lexico.com/definition/Venusian
 | url-status=dead |archive-date=23 March 2020
| archive-url=https://web.archive.org/web/20200323093029/https://www.lexico.com/definition/venusian
}}{{break}}{{MW|Venusian}}</ref>

<!--<ref name=Walker_2017>{{cite web
 | title=Viewing Venus in Broad Daylight
 | first=John | last=Walker
 | work=Fourmilab Switzerland
 | access-date=19 April 2017 | archive-date=29 March 2017
| url=http://www.fourmilab.ch/images/venus_daytime/
 | archive-url=https://web.archive.org/web/20170329024632/https://www.fourmilab.ch/images/venus_daytime/
 | url-status=live }}</ref>

<ref name=Lawrence_2005>{{cite web
 | title=In Search of the Venusian Shadow
 | last=Lawrence | first=Pete | date=2005
 | website=Digitalsky.org.uk | access-date=13 June 2012
| url=http://www.digitalsky.org.uk/venus/shadow-of-venus.html
 | archive-url=https://web.archive.org/web/20120611003523/http://www.digitalsky.org.uk/venus/shadow-of-venus.html
 | archive-date=11 June 2012 }}</ref>-->

<ref name=Souami_Souchay_2012>{{cite journal
 | title=The solar system's invariable plane
 | last1=Souami | first1=D. | last2=Souchay | first2=J.
 | journal=Astronomy & Astrophysics
 | volume=543 | id=A133 | page=11 | date=July 2012
 | doi=10.1051/0004-6361/201219011 | bibcode=2012A&A...543A.133S | doi-access=free }}</ref>

<ref name="Seidelmann2007">{{cite journal
 | title=Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006
 | last1=Seidelmann | first1=P. Kenneth | last2=Archinal | first2=Brent A.
 | last3=A'Hearn<!--written A'hearn here, mostly A'Hearn elsewhere--> | first3=Michael F.
 | last4=Conrad | first4=Albert R. | last5=Consolmagno | first5=Guy J.
 | last6=Hestroffer | first6=Daniel | last7=Hilton | first7=James L.
 | last8=Krasinsky | first8=Georgij A. | last9=Neumann | first9=Gregory A.
 | last10=Oberst | first10=Jürgen | last11=Stooke | first11=Philip J.
 | last12=Tedesco | first12=Edward F. | last13=Tholen | first13=David J.
 | last14=Thomas | first14=Peter C. | last15=Williams | first15=Iwan P.
 | display-authors=3 | journal=[[Celestial Mechanics and Dynamical Astronomy]]
 | volume=98 | issue=3 | pages=155–180 | year=2007
 | bibcode=2007CeMDA..98..155S | doi=10.1007/s10569-007-9072-y
 | ref={{sfnRef|Seidelmann Archinal A'hearn et al.|2007}} | doi-access=free }}</ref>

<ref name="iauwg_ccrsps2000">{{cite web
 | title=Report on the IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites
 | publisher=International Astronomical Union |date=2000
 | url=http://www.hnsky.org/iau-iag.htm
 | access-date=12 April 2007 | archive-date=12 May 2020
| archive-url=https://web.archive.org/web/20200512151452/http://www.hnsky.org/iau-iag.htm
  }}</ref>

<ref name="nasa_venus">{{cite web
 | title=Venus: Facts & Figures | publisher=NASA
 | url=http://sse.jpl.nasa.gov/planets/profile.cfm?Object=Venus&Display=Facts&System=Metric
 | access-date=12 April 2007 | archive-url=https://web.archive.org/web/20060929003116/http://sse.jpl.nasa.gov/planets/profile.cfm?Object=Venus&Display=Facts&System=Metric
 | archive-date=29 September 2006 }}</ref>

<ref name="MallamaSky">{{cite journal
 | title=Planetary magnitudes
 | last=Mallama | first=A. | date=2011
 | journal=Sky & Telescope
 | volume=121 | issue=1 | pages=51–56 }}</ref>

<ref name=VSOP87>{{cite journal
 | title=Numerical expressions for precession formulae and mean elements for the Moon and planets
 | last1=Simon | first1=J.L. | last2=Bretagnon | first2=P.
 | last3=Chapront | first3=J. | last4=Chapront-Touzé | first4=M.
 | last5=Francou | first5=G. | last6=Laskar | first6=J.
 | journal=[[Astronomy and Astrophysics]]
 | volume=282 | issue=2 | pages=663–683 | date=February 1994
 | bibcode=1994A&A...282..663S}}</ref>

<ref name="Konopliv1999">{{cite journal
 | title=Venus Gravity: 180th Degree and Order Model
 | last1=Konopliv | first1=A. S. | last2=Banerdt | first2=W. B.
 | last3=Sjogren | first3=W. L.
 | journal=[[Icarus (journal)|Icarus]]
 | volume=139 |issue=1 |date=May 1999 |pages=3–18
 | bibcode=1999Icar..139....3K |doi=10.1006/icar.1999.6086
 | url=http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/20227/1/98-1117.pdf
 | archive-date=26 May 2010 | archive-url=https://web.archive.org/web/20100526121353/http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/20227/1/98-1117.pdf
 | citeseerx=10.1.1.524.5176 }}</ref>

<ref name="Mallama_and_Hilton">{{cite journal
 | title=Computing apparent planetary magnitudes for The Astronomical Almanac
 | first1=Anthony | last1=Mallama | first2=James L. | last2=Hilton
 | journal=Astronomy and Computing
 | volume=25 | pages=10–24 | date=October 2018
 | doi=10.1016/j.ascom.2018.08.002 | s2cid=69912809 
 | bibcode=2018A&C....25...10M | arxiv=1808.01973 }}</ref>

<ref name="Mallama_et_al">{{cite journal
 | title=Comprehensive wide-band magnitudes and albedos for the planets, with applications to exo-planets and Planet Nine
 | first1=Anthony | last1=Mallama | first2=Bruce | last2=Krobusek
 | first3=Hristo | last3=Pavlov
 | journal=Icarus | volume=282 | pages=19–33 | date=2017
 | doi=10.1016/j.icarus.2016.09.023 |arxiv=1609.05048
 | bibcode=2017Icar..282...19M |s2cid=119307693 }}</ref>

<ref name="Haus_et_al">{{cite journal
 | title=Radiative energy balance of Venus based on improved models of the middle and lower atmosphere
 | first1=R. | last1=Haus | first2=D. | last2=Kappel
 | first3=G. | last3=Arnoldb
 | journal=Icarus
 | volume=272 | pages=178–205 | date=July 2016
 | doi=10.1016/j.icarus.2016.02.048
 | bibcode=2016Icar..272..178H |url=https://elib.dlr.de/109285/1/Haus%20et%20al%202017_ICARUS.pdf
 | access-date=25 June 2019 |archive-date=22 September 2017
| archive-url=https://web.archive.org/web/20170922023312/http://elib.dlr.de/109285/1/Haus%20et%20al%202017_ICARUS.pdf 
 | url-status=live }}</ref>

<ref name="Hashimoto_et_al_2008">{{cite journal
 | title=Felsic highland crust on Venus suggested by Galileo Near-Infrared Mapping Spectrometer data
 | last1=Hashimoto | first1=George L.
 | last2=Roos-Serote | first2=Maarten | last3=Sugita | first3=Seiji
 | last4=Gilmore | first4=Martha S. | last5=Kamp | first5=Lucas W.
 | last6=Carlson | first6=Robert W. | last7=Baines | first7=Kevin H.
 | journal=[[Journal of Geophysical Research: Planets]]
 | publisher=Advancing Earth and Space Science
 | volume=113 | issue=E5 | date=31 December 2008
| bibcode=2008JGRE..113.0B24H | s2cid=45474562
 | doi=10.1029/2008JE003134 | doi-access=}}</ref>

<!-- <ref name=Shiga_2007>{{cite web
 | title=Did Venus's ancient oceans incubate life?
 | first=David | last=Shiga
 | work=New Scientist | date=10 October 2007
| url=https://www.newscientist.com/article/dn12769-did-venuss-ancient-oceans-incubate-life.html
 | access-date=17 September 2017 |archive-date=24 March 2009
| archive-url=https://web.archive.org/web/20090324134332/https://www.newscientist.com/article/dn12769-did-venuss-ancient-oceans-incubate-life.html
 | url-status=live }}</ref>

<ref name="Jakosky">{{cite book
 | title=The New Solar System
 | last=Jakosky |first=Bruce M.
 | chapter=Atmospheres of the Terrestrial Planets
 | editor1-last=Beatty | editor1-first=J. Kelly
 | editor2-last=Petersen | editor2-first=Carolyn Collins
 | editor3-last=Chaikin | editor3-first=Andrew
 | edition=4th | date=1999 | pages=175–200
 | location=Boston |publisher=Sky Publishing
 | isbn=978-0-933346-86-4 |oclc=39464951}}</ref> 

<ref name=NASA_2019>{{Cite web
 | title=Moons
 | website=NASA Solar System Exploration
 | url=https://solarsystem.nasa.gov/moons/overview
 | access-date=26 August 2019 | archive-date=19 October 2019
| archive-url=https://web.archive.org/web/20191019012033/https://solarsystem.nasa.gov/moons/overview/
 | url-status=live}}</ref>-->

<ref name= "Lopes_Gregg_2004">{{cite book
 |title=Volcanic worlds: exploring the Solar System's volcanoes
 | last1=Lopes | first1=Rosaly M. C. | author-link=Rosaly Lopes |last2=Gregg | first2=Tracy K. P.
 | date=2004 | page=61 | publisher=[[Springer Publishing]]
 | isbn=978-3-540-00431-8 }}</ref>

<ref name=Darling_Venus>{{cite encyclopedia
 | title=Venus | encyclopedia=Encyclopedia of Science
 | last=Darling |first=David
 | location=Dundee, Scotland
 | url=https://www.daviddarling.info/encyclopedia/V/Venus.html
 | access-date=24 March 2022 | archive-date=31 October 2021
| archive-url=https://web.archive.org/web/20211031035229/https://www.daviddarling.info/encyclopedia/V/Venus.html
}}</ref>

<ref name="SolarSystemEncyclopedia">{{cite book
 | title=Encyclopedia of the Solar System
 | last=Taylor | first=Fredric W.
 | chapter=Venus: Atmosphere | date=2014
 | publisher=[[Elsevier]] Science & Technology
 | location=Oxford | isbn=978-0-12-415845-0
 | editor1-last=Tilman | editor1-first=Spohn
 | editor2-last=Breuer | editor2-first=Doris
 | editor3-last=Johnson | editor3-first=T. V.
 | access-date=12 January 2016 | archive-date=29 September 2021
| chapter-url=http://literati.credoreference.com/content/entry/estsolar/venus_atmosphere/0
 | archive-url=https://web.archive.org/web/20210929074421/https://search.credoreference.com/content/entry/estsolar/venus_atmosphere/0
 | url-status=live }}</ref>

<ref name=CWRU_2006>{{cite web
 | title=Venus | date=13 September 2006
| publisher=[[Case Western Reserve University]]
 | url=http://burro.cwru.edu/stu/advanced/venus.html
 | access-date=21 December 2011 | archive-date=26 April 2012
| archive-url=https://web.archive.org/web/20120426064658/http://burro.cwru.edu/stu/advanced/venus.html
 }}</ref>

<ref name=Lewis_2004>{{cite book
 | title=Physics and Chemistry of the Solar System
 | first=John S. |last=Lewis |date=2004
 | edition=2nd | publisher=[[Academic Press]]
 | isbn=978-0-12-446744-6
 | url=https://archive.org/details/physicschemistry00lewi_384
 | url-access=limited
 | page=[https://archive.org/details/physicschemistry00lewi_384/page/n477 463] }}</ref>

<ref name=Prockter_2005>{{cite journal
 | title=Ice in the Solar System
 | last=Prockter | first=Louise | date=2005
 | journal=Johns Hopkins APL Technical Digest
 | volume=26 | issue=2 | pages=175–188
 | s2cid=17893191
 | url=https://pdfs.semanticscholar.org/02cc/2fe81ee34f2c70e15c5f1d66244ef69a0e06.pdf
 | access-date=27 July 2009 | archive-date=20 September 2019
| archive-url=https://web.archive.org/web/20190920195147/https://pdfs.semanticscholar.org/02cc/2fe81ee34f2c70e15c5f1d66244ef69a0e06.pdf
  }}</ref>

<ref name="Newitz 2013">{{cite web
 | title=Here's Carl Sagan's original essay on the dangers of climate change
 | last=Newitz | first=Annalee
 | website=Gizmodo | date=11 December 2013
 | url=https://gizmodo.com/heres-carl-sagans-original-essay-on-the-dangers-of-cl-1481304135
 | access-date=3 September 2021 | archive-date=3 September 2021
| archive-url=https://web.archive.org/web/20210903011006/https://gizmodo.com/heres-carl-sagans-original-essay-on-the-dangers-of-cl-1481304135
 | url-status=live }}</ref>

<ref name=Weather>{{Cite web
 | title=The Planet Venus
 | url=https://www.weather.gov/fsd/venus
 | access-date=17 August 2021 | archive-date=7 August 2021
| archive-url=https://web.archive.org/web/20210807222839/https://www.weather.gov/fsd/venus
 | url-status=live }}</ref>

<ref name=Halliday_2020>{{Cite journal
 | title=The origins of volatiles in the terrestrial planets
 | last=Halliday | first=Alex N.
 | url=http://www.sciencedirect.com/science/article/pii/S0016703712006680
 | journal=Geochimica et Cosmochimica Acta
 | volume=105 | pages=146–171 | date=15 March 2013
 | doi=10.1016/j.gca.2012.11.015
 | bibcode=2013GeCoA.105..146H | issn=0016-7037
 | access-date=14 July 2020|archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074423/https://www.sciencedirect.com/science/article/abs/pii/S0016703712006680
 | url-status=live | url-access=subscription
 }}</ref>

<ref name=Owen_et_al_1992>{{Cite journal
 |title=Possible cometary origin of heavy noble gases in the atmospheres of Venus, Earth and Mars
 |last1=Owen | first1=Tobias | last2=Bar-Nun | first2=Akiva
 | last3=Kleinfeld | first3=Idit
 | journal=Nature | date=July 1992
 | volume=358 | issue=6381 | pages=43–46
 | doi=10.1038/358043a0 | pmid=11536499
 | bibcode=1992Natur.358...43O | s2cid=4357750 | issn=1476-4687
 | url=https://www.nature.com/articles/358043a0
 | access-date=14 July 2020 | archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074421/https://www.nature.com/articles/358043a0
 | url-status=live | url-access=subscription }}</ref>

<ref name=Pepin_1991>{{Cite journal
 | title=On the origin and early evolution of terrestrial planet atmospheres and meteoritic volatiles
 | last=Pepin | first=Robert O.
 | journal=Icarus | date=1 July 1991
 | volume=92 | issue=1 | pages=2–79
 | doi=10.1016/0019-1035(91)90036-S
 | bibcode=1991Icar...92....2P
 | issn=0019-1035 }}</ref>

<ref name=Namiki_Solomon_1998>{{Cite journal
 | title=Volcanic degassing of argon and helium and the history of crustal production on Venus
 | last1=Namiki | first1=Noriyuki | last2=Solomon | first2=Sean C.
 | journal=Journal of Geophysical Research: Planets
 | volume=103 | issue=E2 | pages=3655–3677 | year=1998
 | doi=10.1029/97JE03032 | doi-access=free
 | bibcode=1998JGR...103.3655N | issn=2156-2202 }}</ref>

<ref name="O'Rurke_Korenaga_2015">{{Cite journal
 | title=Thermal evolution of Venus with argon degassing
 | last1=O'Rourke | first1=Joseph G. | last2=Korenaga | first2=Jun
 | url=http://www.sciencedirect.com/science/article/pii/S0019103515003000
 | journal=Icarus | date=1 November 2015
 | volume=260 | pages=128–140
 | doi=10.1016/j.icarus.2015.07.009
 | bibcode=2015Icar..260..128O
 | issn=0019-1035| url-access=subscription
 }}</ref>

<ref name="baas39_540">{{Cite journal
 | title=Searching for Evidence of Past Oceans on Venus
 | last1=Grinspoon |first1=David H. |author-link=David Grinspoon
 | last2=Bullock |first2=M. A.
 | journal=[[Bulletin of the American Astronomical Society]]
 | volume=39 | page=540 | date=October 2007
 | bibcode=2007DPS....39.6109G }}</ref>

<ref name="Kasting">{{cite journal
 | title=Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus
 | last=Kasting |first=J. F. |author-link=James Kasting
 | journal=Icarus | year=1988
 | volume=74 | issue=3 | pages=472–494
 | doi=10.1016/0019-1035(88)90116-9 | pmid=11538226
 | bibcode=1988Icar...74..472K
 | url=https://zenodo.org/record/1253896
 | access-date=25 June 2019 | archive-date=7 December 2019
| archive-url=https://web.archive.org/web/20191207210741/https://zenodo.org/record/1253896
 | url-status=live }}</ref>

<ref name=Mullen_2002>{{cite web
 | title=Venusian Cloud Colonies
 | first=Leslie | last=Mullen
 | work=Astrobiology Magazine
 | date=13 November 2002
| url=http://www.astrobio.net/news-exclusive/venusian-cloud-colonies/
 | archive-url=https://web.archive.org/web/20140816070045/http://www.astrobio.net/news-exclusive/venusian-cloud-colonies/
 | archive-date=16 August 2014 }}</ref>

<ref name=Landis_2003>{{cite journal
 | title=Astrobiology: The Case for Venus
 | first=Geoffrey A. | last=Landis | author-link=Geoffrey A. Landis
 | journal=Journal of the British Interplanetary Society
 | volume=56 | issue=7–8 | pages=250–254 | date=July 2003
 | id=NASA/TM—2003-212310
 | bibcode=2003JBIS...56..250L
 | url=http://gltrs.grc.nasa.gov/reports/2003/TM-2003-212310.pdf
 | archive-url=https://web.archive.org/web/20110807004311/http://gltrs.grc.nasa.gov/reports/2003/TM-2003-212310.pdf 
 | archive-date=7 August 2011 }}</ref>

<ref name="Cockell1999">{{cite journal
 | title=Life on Venus
 | last=Cockell | first=Charles S. | author-link=Charles S. Cockell
 | journal=[[Planetary and Space Science]]
 | volume=47 | issue=12 | pages=1487–1501 | date=December 1999
 | doi=10.1016/S0032-0633(99)00036-7 | bibcode=1999P&SS...47.1487C}}</ref>

<ref name=Drake_2020>{{cite news
 | title=Possible sign of life on Venus stirs up heated debate
 | last=Drake | first=Nadia | author-link=Nadia Drake
 | work=National Geographic | date=14 September 2020
| url=https://www.nationalgeographic.com/science/2020/09/possible-sign-of-life-found-on-venus-phosphine-gas/
 | access-date=14 September 2020 | archive-date=14 September 2020
| archive-url=https://web.archive.org/web/20200914153820/https://www.nationalgeographic.com/science/2020/09/possible-sign-of-life-found-on-venus-phosphine-gas/
 | url-status=dead }}</ref>

<ref name=Greaves_et_al_2020>{{cite journal
 | title=Phosphine gas in the cloud decks of Venus
 | last1=Greaves | first1=J. S. | last2=Richards | first2=A. M. S.
 | last3=Bains |first3=W. | first4=P. B. | last4=Rimmer
 | first5=H. | last5=Sagawa | first6=D. L. | last6=Clements
 | first7=S. | last7=Seager | first8=J. J. | last8=Petkowski
 | first9=Clara | last9=Sousa-Silva | first10=Sukrit | last10=Ranjan
 | first11=Emily | last11=Drabek-Maunder | first12=Helen J. | last12=Fraser
 | first13=Annabel | last13=Cartwright | first14=Ingo | last14=Mueller-Wodarg
 | first15=Zhuchang | last15=Zhan | first16=Per | last16=Friberg
 | first17=Iain | last17=Coulson | first18=E'lisa | last18=Lee
 | first19=Jim | last19=Hoge
 | journal=Nature Astronomy
 | year=2020 | volume=5 | issue=7 | pages=655–664
 | doi=10.1038/s41550-020-1174-4 |arxiv=2009.06593
 | bibcode=2021NatAs...5..655G |s2cid=221655755
 | url=https://www.nature.com/articles/s41550-020-1174-4 |access-date=14 September 2020
| archive-date=14 September 2020
| archive-url=https://web.archive.org/web/20200914150731/https://www.nature.com/articles/s41550-020-1174-4
 | url-status=live }}</ref>

<ref name=Lincowski_et_al_2021>{{Cite journal
 | title=Claimed Detection of PH<sub>3</sub> in the Clouds of Venus is Consistent with Mesospheric SO2
 | last1=Lincowski | first1=Andrew P. | last2=Meadows | first2=Victoria S.
 | last3=Crisp | first3=David | last4=Akins | first4=Alex B.
 | last5=Schwieterman | first5=Edward W. | last6=Arney | first6=Giada N.
 | last7=Wong | first7=Michael L. | last8=Steffes | first8=Paul G.
 | last9=Parenteau | first9=M. Niki | last10=Domagal-Goldman | first10=Shawn
 | journal=The Astrophysical Journal
 | volume=908 | issue=2 | pages=L44 | year=2021
 | doi=10.3847/2041-8213/abde47 | arxiv=2101.09837
 | bibcode=2021ApJ...908L..44L | s2cid=231699227
 | doi-access=free }}</ref>

<ref name=Beall_2020>{{cite journal
 | title=More doubts cast on potential signs of life on Venus
 | first=Abigail
 | last=Beall
 | journal=New Scientist
 | date=21 October 2020
| doi=10.1016/S0262-4079(20)31910-2
 | s2cid=229020261
 | url=https://www.newscientist.com/article/2257987-more-doubts-cast-on-potential-signs-of-life-on-venus/
 | access-date=29 January 2023
 | archive-date=26 December 2021
| archive-url=https://web.archive.org/web/20211226090543/https://www.newscientist.com/article/2257987-more-doubts-cast-on-potential-signs-of-life-on-venus/
 | url-status=live
 | url-access=subscription
 }}</ref>

<ref name=Snellan_et_al_2020>{{cite journal | title=Re-analysis of the 267 GHz ALMA observations of Venus | first1=I. A. G. | last1=Snellen | first2=L. | last2=Guzman-Ramirez | first3=M. R. | last3=Hogerheijde | first4=A. P. S. | last4=Hygate | first5=F. F. S. | last5=van der Tak | journal=Astronomy & Astrophysics | date=December 2020 | volume=644 | pages=L2 | doi=10.1051/0004-6361/202039717 | arxiv=2010.09761 | s2cid=224803085 | bibcode=2020A&A...644L...2S | url=https://www.aanda.org/articles/aa/full_html/2020/12/aa39717-20/aa39717-20.html | access-date=29 January 2023 | doi-access=free | archive-date=16 January 2022 | archive-url=https://web.archive.org/web/20220116181254/https://www.aanda.org/articles/aa/full_html/2020/12/aa39717-20/aa39717-20.html | url-status=live }}</ref>

<ref name=Moshkin_et_al_1979>{{cite journal
 | title=Dust on the surface of Venus
 | last1=Moshkin | first1=B. E. | last2=Ekonomov | first2=A. P.
 | last3=Golovin | first3=Iu. M.
 | journal=Kosmicheskie Issledovaniia (Cosmic Research)
 | volume=17 | issue=2 | pages=280–285 | year=1979
 | bibcode=1979CosRe..17..232M}}</ref>

<ref name="kras006">{{cite journal
 | title=Chemical composition of the atmosphere of Venus
 | last1=Krasnopolsky | first1=V. A. | last2=Parshev | first2=V. A.
 | journal=Nature | year=1981
 | volume=292 | issue=5824 | pages=610–613
 | doi=10.1038/292610a0 | bibcode=1981Natur.292..610K
 | s2cid=4369293 }}</ref>

<ref name=Krasnopolsky_2006>{{cite journal
 | title=Chemical composition of Venus atmosphere and clouds: Some unsolved problems
 | first=Vladimir A. |last=Krasnopolsky
 | journal=[[Planetary and Space Science]]
 | volume=54 | issue=13–14 | pages=1352–1359 | year=2006
 | doi=10.1016/j.pss.2006.04.019 | bibcode=2006P&SS...54.1352K }}</ref>

<ref name=Rossow_et_al_1990>{{cite journal
 | title=Cloud-tracked winds from Pioneer Venus OCPP images
 | first1=W. B. | last1=Rossow | first2=A. D. | last2=del Genio
 | first3=T. | last3=Eichler
 | journal=[[Journal of the Atmospheric Sciences]]
 | volume=47 | issue=17 | pages=2053–2084 | year=1990
 | doi=10.1175/1520-0469(1990)047<2053:CTWFVO>2.0.CO;2
 | issn=1520-0469 |bibcode=1990JAtS...47.2053R
 | doi-access=free }}</ref>

<ref name="science328">{{cite journal
 | last=Normile | first=Dennis
 | title=Mission to probe Venus's curious winds and test solar sail for propulsion
 | journal=Science | date=7 May 2010
| page=677 | issue=5979 | volume=328
 | pmid=20448159 | doi=10.1126/science.328.5979.677-a
 | bibcode=2010Sci...328..677N }}</ref>

<ref name=stellar>{{cite web
 | title=Useful Constants
 | author=IERS | author-link=IERS
 | publisher=L'Observatoire de Paris
 | date=13 March 2021
| url=https://hpiers.obspm.fr/eop-pc/models/constants.html
 | access-date=16 April 2021 | archive-date=11 March 2019
| archive-url=https://web.archive.org/web/20190311164700/http://hpiers.obspm.fr/eop-pc/models/constants.html
 | url-status=live }}</ref>

<ref name=CASTOR>{{cite web
 | title=Rotation Speed
 | last=Earl | first=Michael A.
 | publisher=Canadian Astronomy, Satellite Tracking and Optical Research (CASTOR)
 | url=http://www.castor2.ca/16_Calc/03_Rotation/index.html
 | access-date=16 April 2021 |archive-date=17 July 2019
| archive-url=https://web.archive.org/web/20190717213345/http://www.castor2.ca/16_Calc/03_Rotation/index.html
 | url-status=live }}</ref>

<ref name="VaqueroVázquez2009">{{cite book
 | title=The Sun Recorded Through History
 | first1=J. M. | last1=Vaquero | first2=M. | last2=Vázquez
 | publisher=Springer Science & Business Media
 | isbn=978-0-387-92790-9 | year=2009 | page=75
 | url=https://books.google.com/books?id=iWkyiEeiyksC&pg=PA75
 | access-date=18 May 2016 |archive-date=26 November 2016
| archive-url=https://web.archive.org/web/20161126005506/https://books.google.com/books?id=iWkyiEeiyksC&pg=PA75
 | url-status=live }}</ref>

<ref name="Kennard">{{cite book
 | title=Thought Experiments: Popular Thought Experiments in Philosophy, Physics, Ethics, Computer Science & Mathematics
 | first=Fredrick | last=Kennard | year=2015
 | isbn=978-1-329-00342-2 | page=113
 | publisher=Lulu.com | url=https://books.google.com/books?id=sX-pCQAAQBAJ&pg=PA113
 | access-date=18 May 2016 |archive-date=25 November 2016
| archive-url=https://web.archive.org/web/20161125223727/https://books.google.com/books?id=sX-pCQAAQBAJ&pg=PA113
 | url-status=live }}</ref>

<ref name="fact">{{cite web
 | title=Venus Fact Sheet
 | last=Williams | first=David R. | date=25 November 2020
| publisher=NASA Goddard Space Flight Center
 | url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
 | access-date=15 April 2021 | archive-date=11 May 2018
| archive-url=https://web.archive.org/web/20180511140851/https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
 | url-status=live }}</ref>

<ref name=Lorenz_et_al_2001>{{cite journal
 | title=Titan, Mars and Earth: Entropy Production by Latitudinal Heat Transport
 | last1=Lorenz | first1=Ralph D. | last2=Lunine | first2=Jonathan I.
 | last3=Withers | first3=Paul G. | last4=McKay | first4=Christopher P.
 | journal=Geophysical Research Letters
 | volume=28 | issue=3 | pages=415–418 | date=1 February 2001
| publisher=[[Ames Research Center]], University of Arizona Lunar and Planetary Laboratory
 | doi=10.1029/2000GL012336 | bibcode=2001GeoRL..28..415L
 | s2cid=15670045 | url=http://sirius.bu.edu/withers/pppp/pdf/mepgrl2001.pdf
 | access-date=21 August 2007 | archive-date=3 October 2018
| archive-url=https://web.archive.org/web/20181003224659/http://sirius.bu.edu/withers/pppp/pdf/mepgrl2001.pdf
 | url-status=live }}</ref>

<ref name=NASA_Seasons>{{cite web
 | title=Interplanetary Seasons | date=19 June 2000
| website=NASA Science | publisher=NASA
 | url=https://science.nasa.gov/science-news/science-at-nasa/2000/interplanetaryseasons
 | access-date=14 April 2021 | archive-date=14 April 2021
| archive-url=https://web.archive.org/web/20210414193149/https://science.nasa.gov/science-news/science-at-nasa/2000/interplanetaryseasons
 | url-status=live }}</ref>

<ref name="Basilevsky_2003">{{cite journal
 | title=The surface of Venus
 | last1=Basilevsky | first1=A. T. | last2=Head | first2=J. W.
 | journal=[[Reports on Progress in Physics]]
 | year=2003 | volume=66 | issue=10 | pages=1699–1734
 | doi=10.1088/0034-4885/66/10/R04
 | bibcode=2003RPPh...66.1699B | s2cid=13338382
 | url=https://semanticscholar.org/paper/13e87bf184cd5ab307423190918ae68f05a13667
 | access-date=2 December 2019 | archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074436/https://www.semanticscholar.org/paper/The-surface-of-Venus-Basilevsky-Head/13e87bf184cd5ab307423190918ae68f05a13667
 | url-status=live }}</ref>

<ref name="McGill_2010">{{cite book
 | title=Planetary Tectonics | year=2010
 | chapter=Venus tectonics
 | last1=McGill | first1=G. E. | last2=Stofan | first2=E. R.
 | last3=Smrekar | first3=S. E.
 | editor1-first=T. R. | editor1-last=Watters
 | editor2-first=R. A. | editor2-last=Schultz
 | publisher=Cambridge University Press
 | isbn=978-0-521-76573-2 | pages=81–120
 | chapter-url=https://books.google.com/books?id=9PD5hxPb6fkC&pg=PA81
 | access-date=18 October 2015 | archive-date=23 June 2016
| archive-url=https://web.archive.org/web/20160623194433/https://books.google.com/books?id=9PD5hxPb6fkC&pg=PA81
 | url-status=live }}</ref>

<ref name=Otten_2004>{{cite web
 | title="Heavy metal" snow on Venus is lead sulfide
 | first=Carolyn Jones |last=Otten | year=2004
 | publisher=[[Washington University in St. Louis]]
 | url=http://news-info.wustl.edu/news/page/normal/633.html
 | access-date=21 August 2007 |archive-date=15 April 2008
| archive-url=https://web.archive.org/web/20080415000214/http://news-info.wustl.edu/news/page/normal/633.html
 | url-status=live }}</ref>

<ref name="Lorentz_2018">{{Cite journal
 | title=Lightning detection on Venus: a critical review
 | last=Lorenz | first=Ralph D. | date=20 June 2018
 | journal=Progress in Earth and Planetary Science
 | volume=5 | issue=1 | page=34
 | doi=10.1186/s40645-018-0181-x | doi-access=free
 | bibcode=2018PEPS....5...34L | issn=2197-4284 }}</ref>

<ref name="Kranopol'skii_1980">{{cite journal
 | title=Lightning on Venus according to Information Obtained by the Satellites ''Venera 9'' and ''10''
 | last1=Kranopol'skii | first1=V. A. | date=1980
 | journal=Cosmic Research
 | volume=18 | issue=3 | pages=325–330
 | bibcode=1980CosRe..18..325K }}</ref>

<ref name="Russell, Philips">{{cite journal
 | title=The Ashen Light
 | last1=Russell | first1=C. T. | last2=Phillips | first2=J. L.
 | url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/ashen/
 | journal=[[Advances in Space Research]]
 | volume=10 | issue=5 | pages=137–141 | year=1990
 | bibcode=1990AdSpR..10e.137R | doi=10.1016/0273-1177(90)90174-X
 | access-date=10 September 2015 | archive-date=8 December 2015
| archive-url=https://web.archive.org/web/20151208005538/http://www-ssc.igpp.ucla.edu/personnel/russell/papers/ashen/
 | url-status=live | url-access=subscription }}</ref>

<ref name=Venera_12>{{cite web
 | title=''Venera 12'' Descent Craft
 | work=[[National Space Science Data Center]]
 | publisher=NASA
 | url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-086C
 | access-date=10 September 2015 | archive-date=23 May 2019
| archive-url=https://web.archive.org/web/20190523181039/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-086C
 | url-status=live }}</ref>

<ref name="Russell_2007">{{cite journal
 | title=Lightning on Venus inferred from whistler-mode waves in the ionosphere
 | last1=Russell | first1=C. T.| last2=Zhang | first2=T. L.
 | last3=Delva | first3=M.| last4=Magnes | first4=W.
 | last5=Strangeway | first5=R. J. | last6=Wei | first6=H. Y.
 | journal=[[Nature (journal)|Nature]]
 | volume=450 | issue=7170 | pages=661–662 | date=November 2007
 | bibcode=2007Natur.450..661R | pmid=18046401
 | doi=10.1038/nature05930 | s2cid=4418778
 | url=http://aten.igpp.ucla.edu/personnel/russell/papers/lightning_venus_whistler-mode_waves.pdf
 | access-date=10 September 2015 | archive-date=4 March 2016
| archive-url=https://web.archive.org/web/20160304120534/http://aten.igpp.ucla.edu/personnel/russell/papers/lightning_venus_whistler-mode_waves.pdf
  }}</ref>

<ref name=Hand_2007>{{cite journal
 | last=Hand | first=Eric | date=November 2007
 | title=European mission reports from Venus
 | journal=Nature | issue=450 | pages=633–660
 | doi=10.1038/news.2007.297 | doi-access=free
 | s2cid=129514118 }}</ref>

<ref name=BBC_2007_11_28>{{cite news
 | author=Staff
 | date=28 November 2007
| title=Venus offers Earth climate clues
 | work=[[BBC News]]
 | url=http://news.bbc.co.uk/1/hi/sci/tech/7117303.stm
 | access-date=29 November 2007 | archive-date=11 January 2009
| archive-url=https://web.archive.org/web/20090111155813/http://news.bbc.co.uk/1/hi/sci/tech/7117303.stm
 | url-status=live}}</ref>

<ref name="esaozone">{{cite web
 | title=ESA finds that Venus has an ozone layer too
 | publisher=European Space Agency | date=6 October 2011
| access-date=25 December 2011 | archive-date=27 January 2012
| url=http://www.esa.int/esaCP/SEMU3N9U7TG_Life_0.html
 | archive-url=https://web.archive.org/web/20120127202150/http://www.esa.int/esaCP/SEMU3N9U7TG_Life_0.html
 | url-status=live }}</ref>

<ref name="ESA-20130129">{{cite web
 | title=When A Planet Behaves Like A Comet 
 | date=29 January 2013
| publisher=European Space Agency
 | url=http://www.esa.int/Our_Activities/Space_Science/When_a_planet_behaves_like_a_comet
 | access-date=31 January 2013 |archive-date=2 May 2019
| archive-url=https://web.archive.org/web/20190502073711/http://www.esa.int/Our_Activities/Space_Science/When_a_planet_behaves_like_a_comet
 | url-status=live }}</ref>

<ref name="Space-20130130">{{cite web
 | title=Venus Can Have 'Comet-Like' Atmosphere
 | last=Kramer | first=Miriam
 | url=http://www.space.com/19537-venus-comet-atmosphere.html
 | date=30 January 2013 | work=[[Space.com]]
 | access-date=31 January 2013 |archive-date=3 May 2019
| archive-url=https://web.archive.org/web/20190503055127/https://www.space.com/19537-venus-comet-atmosphere.html
 | url-status=live }}</ref>

<ref name=Fukuhara_et_al_2017>{{cite journal
 | title=Large stationary gravity wave in the atmosphere of Venus
 | last1=Fukuhara | first1=Tetsuya | last2=Futaguchi | first2=Masahiko
 | last3=Hashimoto | first3=George L. | last4=Horinouchi | first4=Takeshi
 | last5=Imamura | first5=Takeshi | last6=Iwagaimi | first6=Naomoto
 | last7=Kouyama | first7=Toru | last8=Murakami | first8=Shin-ya
 | last9=Nakamura | first9=Masato | last10=Ogohara| first10=Kazunori
 | last11=Sato | first11=Mitsuteru | last12=Sato | first12=Takao M.
 | last13=Suzuki | first13=Makoto | last14=Taguchi | first14=Makoto
 | last15=Takagi | first15=Seiko | last16=Ueno | first16=Munetaka
 | last17=Watanabe | first17=Shigeto | last18=Yamada | first18=Manabu
 | last19=Yamazaki | first19=Atsushi
 | journal=Nature Geoscience | date=16 January 2017
| volume=10 | issue=2 | pages=85–88
 | doi=10.1038/ngeo2873 | bibcode=2017NatGe..10...85F }}</ref>

<ref name=Rincon_2017>{{cite news
 | title=Venus wave may be Solar System's biggest
 | last=Rincon |first=Paul
 | url=https://www.bbc.com/news/science-environment-38638067
 | work=BBC News | date=16 January 2017
| access-date=17 January 2017 | archive-date=17 January 2017
| archive-url=https://web.archive.org/web/20170117002347/http://www.bbc.com/news/science-environment-38638067
 | url-status=live }}</ref>

<ref name=Chang_2017>{{cite news
 | title=Venus Smiled, With a Mysterious Wave Across Its Atmosphere
 | last=Chang | first=Kenneth
 | work=The New York Times | date=16 January 2017
| url=https://www.nytimes.com/2017/01/16/science/venus-wave-akatsuki.html?_r=0
 | access-date=17 January 2017 | archive-date=15 July 2017
| archive-url=https://web.archive.org/web/20170715231853/https://www.nytimes.com/2017/01/16/science/venus-wave-akatsuki.html?_r=0
 | url-status=live }}</ref>

<ref name=Mueller_2014>{{cite book
 | title=Encyclopedia of the Solar System
 | last1=Mueller |first1=Nils
 | editor1-last=Tilman |editor1-first=Spohn
 | editor2-last=Breuer |editor2-first=Doris
 | editor3-last=Johnson |editor3-first=T. V.
 | edition=3rd | date=2014
 | publisher=Elsevier Science & Technology
 | location=Oxford | isbn=978-0-12-415845-0
 | chapter-url=http://literati.credoreference.com/content/entry/estsolar/venus_surface_and_interior/0
 | chapter=Venus Surface and Interior
 | access-date=12 January 2016 |archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074445/https://search.credoreference.com/content/entry/estsolar/venus_surface_and_interior/0
 | url-status=live }}</ref>

<ref name=Esposito_1984>{{cite journal
 | title=Sulfur Dioxide: Episodic Injection Shows Evidence for Active Venus Volcanism
 | first=Larry W. | last=Esposito | author-link=Larry W. Esposito
 | journal=[[Science (journal)|Science]] | date=9 March 1984
| volume=223 |issue=4640 |pages=1072–1074
 | doi=10.1126/science.223.4640.1072 |pmid=17830154
 | bibcode=1984Sci...223.1072E |s2cid=12832924
 }}</ref>

<ref name=Bullock_Grinspoon_2001>{{cite journal
 | title=The Recent Evolution of Climate on Venus
 | last1=Bullock |first1=Mark A.
 | last2=Grinspoon |first2=David H. |author-link2=David Grinspoon
 | journal=[[Icarus (journal)|Icarus]]
 | volume=150 | issue=1 | date=March 2001 | pages=19–37
 | doi=10.1006/icar.2000.6570 |bibcode=2001Icar..150...19B
 | url=http://www.boulder.swri.edu/~bullock/vclime.pdf 
 | archive-url=https://web.archive.org/web/20031023161615/http://www.boulder.swri.edu/~bullock/vclime.pdf
 | archive-date=23 October 2003
| citeseerx=10.1.1.22.6440 }}</ref>

<ref name=Basilevsky_Head_1995>{{cite journal
 | title=Global stratigraphy of Venus: Analysis of a random sample of thirty-six test areas
 | last1=Basilevsky | first1=Alexander T. | last2=Head | first2=James W. III
 | journal=[[Earth, Moon, and Planets]]
 | volume=66 | issue=3 | pages=285–336 | date=1995
 | bibcode=1995EM&P...66..285B | doi=10.1007/BF00579467
 | s2cid=21736261 }}</ref>

<ref name="planetology">{{cite book
 | title=Planetology: Unlocking the Secrets of the Solar System
 | last1=Jones | first1=Tom | last2=Stofan | first2=Ellen
 | page=74 | date=2008 |isbn=978-1-4262-0121-9
 | publisher=National Geographic Society
 | url=https://books.google.com/books?id=SL-BszT15s0C&pg=PA74
 | access-date=20 April 2017 |archive-date=16 July 2017
| archive-url=https://web.archive.org/web/20170716230502/https://books.google.com/books?id=SL-BszT15s0C&pg=PA74
 | url-status=live }}</ref>

<ref name="Kaufmann">{{cite book
 | last=Kaufmann | first=W. J.
 | date=1994 | title=Universe
 | publisher=[[W. H. Freeman]] | location=New York
 | page=204 | isbn=978-0-7167-2379-0}}</ref>

<ref name="Frankel">{{cite book
 | title=Volcanoes of the Solar System
 | first=Charles | last=Frankel | date=1996
 | url=https://archive.org/details/volcanoesofsolar0000fran
 | publisher=Cambridge University Press |isbn=978-0-521-47770-3
 | url-access=registration | access-date=30 January 2023 }}</ref>

<ref name=Batson_Russell_1991>{{cite conference
 | title=Naming the Newly Found Landforms on Venus
 | last1=Batson | first1=R.M. | last2=Russell | first2=J. F.
 | book-title=Proceedings of the Lunar and Planetary Science Conference XXII
 | date=18–22 March 1991 |location=Houston, Texas | page=65
 | bibcode=1991pggp.rept..490B
 | url=http://www.lpi.usra.edu/meetings/lpsc1991/pdf/1033.pdf
 | access-date=12 July 2009 | archive-date=13 May 2011
| archive-url=https://web.archive.org/web/20110513162948/http://www.lpi.usra.edu/meetings/lpsc1991/pdf/1033.pdf
 | url-status=live }}</ref>

<ref name="jpl-magellan">{{cite book
 | title=The Magellan Venus Explorer's Guide
 | editor-first=Carolynn | editor-last=Young
 | publisher=Jet Propulsion Laboratory
 | location=California | page=93 | date=1 August 1990
| url=http://www2.jpl.nasa.gov/magellan/guide8.html
 | access-date=13 January 2016 | archive-date=4 December 2016
| archive-url=https://web.archive.org/web/20161204023231/http://www2.jpl.nasa.gov/magellan/guide8.html
 | url-status=live }}</ref>

<ref name="jpl-magellan2">{{cite book
 | title=The Magellan Venus Explorer's Guide
 | editor-first=Carolynn | editor-last=Young
 | publisher=Jet Propulsion Laboratory
 | location=California | pages=99–100 | date=1 August 1990
| url=http://www2.jpl.nasa.gov/magellan/guide8.html
 | access-date=13 January 2016 |archive-date=4 December 2016
| archive-url=https://web.archive.org/web/20161204023231/http://www2.jpl.nasa.gov/magellan/guide8.html
 | url-status=live }}</ref>

<ref name="Davies_1994">{{cite journal
 |title=Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites
 | last1=Davies | first1=M. E. | last2=Abalakin | first2=V. K.
 | last3=Bursa | first3=M. | last4=Lieske | first4=J. H.
 | last5=Morando | first5=B. | last6=Morrison | first6=D.
 | last7=Seidelmann | first7=P. K. | last8=Sinclair | first8=A. T.
 | last9=Yallop | first9=B.| last10=Tjuflin | first10= Y. S.
 | journal=Celestial Mechanics and Dynamical Astronomy
 | volume=63 | issue=2 | pages=127–148 | year=1994
 | doi=10.1007/BF00693410 | s2cid=189850694
 | bibcode=1996CeMDA..63..127D }}</ref>

<ref name=Seidelmann_et_al_2007>{{cite journal
 | title=Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006
 | first1=P. | last1=Kenneth Seidelmann | first2=B. A. | last2=Archinal
 | first3=M. F. | last3=A'hearn | first4=A. | last4=Conrad
 | first5=G. J. | last5=Consolmagno | first6=D. | last6=Hestroffer
 | first7=J. L. | last7=Hilton | first8=G. A. | last8=Krasinsky
 | first9=G. | last9=Neumann | first10=J. | last10=Oberst
 | first11=P. | last11=Stooke | first12=E. F. | last12=Tedesco
 | first13=D. J. | last13=Tholen | first14=P. C. | last14=Thomas
 | first15=I. P. | last15=Williams
 | journal=Celestial Mechanics and Dynamical Astronomy
 | volume=98 | pages=155–180 | date=July 2007 | issue=3
 | doi=10.1007/s10569-007-9072-y | doi-access=free
 | bibcode=2007CeMDA..98..155S }}</ref>

<ref name=Helbert_et_al_2008>{{Cite journal
 |title=Surface brightness variations seen by VIRTIS on Venus Express and implications for the evolution of the Lada Terra region, Venus
 | last1=Helbert | first1=Jörn | last2=Müller | first2=Nils
 | last3=Kostama | first3=Petri | last4=Marinangeli | first4=Lucia
 | last5=Piccioni | first5=Giuseppe | last6=Drossart | first6=Pierre
 | journal=Geophysical Research Letters
 | volume=35 | issue=11 | pages=L11201 | date=2008
 | doi=10.1029/2008GL033609 | doi-access=free
 | bibcode=2008GeoRL..3511201H | issn=1944-8007 | url=https://hal.science/hal-03742627/file/Geophysical%20Research%20Letters%20-%202008%20-%20Helbert%20-%20Surface%20brightness%20variations%20seen%20by%20VIRTIS%20on%20Venus%20Express%20and.pdf }}</ref>

<ref name=Gilmore_et_al_2017>{{Cite journal
 | title=Venus Surface Composition Constrained by Observation and Experiment
 | last1=Gilmore | first1=Martha | last2=Treiman | first2=Allan
 | last3=Helbert | first3=Jörn | last4=Smrekar | first4=Suzanne
 | journal=Space Science Reviews
 | volume=212 | issue=3 | pages=1511–1540 | date=1 November 2017
 | doi=10.1007/s11214-017-0370-8 | s2cid=126225959
 | bibcode=2017SSRv..212.1511G | issn=1572-9672 }}</ref>
 
<ref name=Karttunen_et_al_2007>{{cite book
 | last1=Karttunen | first1=Hannu | last2=Kroger | first2=P.
 | last3=Oja | first3=H. | last4=Poutanen | first4=M.
 | last5=Donner | first5=K. J.
 | title=Fundamental Astronomy
 | page=162 | publisher=Springer | date=2007
 | isbn=978-3-540-34143-7
 | url=https://archive.org/details/fundamentalastro00kart_346/page/n167
 | access-date=30 January 2023 }}</ref>

<ref name="ESA_2012-12-03">{{cite web
 | title=Have Venusian volcanoes been caught in the act?
 | first=Markus | last=Bauer | date=3 December 2012
| publisher=European Space Agency
 | url=https://www.esa.int/Science_Exploration/Space_Science/Venus_Express/Have_Venusian_volcanoes_been_caught_in_the_act
 | access-date=14 April 2021 | archive-date=14 April 2021
| archive-url=https://web.archive.org/web/20210414194210/https://www.esa.int/Science_Exploration/Space_Science/Venus_Express/Have_Venusian_volcanoes_been_caught_in_the_act
 | url-status=live }}</ref>

<ref name=Glaze_1999>{{cite journal
 | title=Transport of SO<sub>2</sub> by explosive volcanism on Venus
 | first=Lori S. |last=Glaze
 | journal=[[Journal of Geophysical Research]]
 | volume=104 | issue=E8 | pages=18899–18906 | date=August 1999
 | doi=10.1029/1998JE000619 | doi-access=free
 | bibcode=1999JGR...10418899G }}</ref>

<ref name="Marcq2012">{{cite journal
 | title=Variations of sulphur dioxide at the cloud top of Venus's dynamic atmosphere
 | first1=Emmanuel | last1=Marcq | first2=Jean-Loup | last2=Bertaux
 | first3=Franck | last3=Montmessin | first4=Denis | last4=Belyaev
 | journal=Nature Geoscience
 | volume=6 | issue=1 | pages=25–28 | date=January 2013
 | doi=10.1038/ngeo1650 | bibcode=2013NatGe...6...25M
 | s2cid=59323909
 }}</ref>

<ref name="NYT-20200109">{{cite news
 | title=Volcanoes on Venus Might Still Be Smoking - Planetary science experiments on Earth suggest that the sun's second planet might have ongoing volcanic activity
 | last=Hall | first=Sannon
 | url=https://www.nytimes.com/2020/01/09/science/venus-volcanoes-active.html
 | date=9 January 2020 | work=[[The New York Times]]
 | access-date=10 January 2020 | archive-date=9 January 2020
| archive-url=https://web.archive.org/web/20200109234012/https://www.nytimes.com/2020/01/09/science/venus-volcanoes-active.html
 | url-status=live }}</ref>

<ref name="SCI-20200103">{{cite journal
 | title=Present-day volcanism on Venus as evidenced from weathering rates of olivine
 | last=Filiberto | first=Justin | date=3 January 2020
| journal=[[Science (journal)|Science]]
 | volume=6 | number=1 | pages=eaax7445
 | doi=10.1126/sciadv.aax7445 | doi-access=free | pmc=6941908
 | bibcode=2020SciA....6.7445F | pmid=31922004 }}</ref>

<ref name="USGS_Ganis_Chasma">{{cite web
 | title=Ganis Chasma
 | work=Gazetteer of Planetary Nomenclature
 | publisher=[[USGS Astrogeology Science Center]]
 | url=https://planetarynames.wr.usgs.gov/Feature/2099
 | access-date=14 April 2021 | archive-date=13 October 2018
| archive-url=https://web.archive.org/web/20181013014548/https://planetarynames.wr.usgs.gov/Feature/2099
 | url-status=live }}</ref>

<ref name="Lakdawalla2015">{{cite web
 | title=Transient hot spots on Venus: Best evidence yet for active volcanism
 | last=Lakdawalla | first=Emily | author-link=Emily Lakdawalla
 | publisher=[[The Planetary Society]] | date=18 June 2015
| url=http://www.planetary.org/blogs/emily-lakdawalla/2015/06181637-transient-hot-spots-on-venus.html
 | access-date=20 June 2015 | archive-date=20 June 2015
| archive-url=https://web.archive.org/web/20150620081122/http://www.planetary.org/blogs/emily-lakdawalla/2015/06181637-transient-hot-spots-on-venus.html
 | url-status=live }}</ref>

<ref name="ESA_2015-06-18">{{cite web
 | title=Hot lava flows discovered on Venus
 | publisher=European Space Agency |date=18 June 2015
| url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Hot_lava_flows_discovered_on_Venus
 | access-date=20 June 2015 | archive-date=19 June 2015
| archive-url=https://web.archive.org/web/20150619071101/http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Hot_lava_flows_discovered_on_Venus
}}</ref>

<ref name="Shalygin2015">{{cite journal
 | last1=Shalygin | first1=E. V. | last2=Markiewicz | first2=W. J.
 | last3=Basilevsky | first3=A. T. | last4=Titov | first4=D. V.
 | last5=Ignatiev | first5=N. I. | last6=Head | first6=J. W.
 | title=Active volcanism on Venus in the Ganiki Chasma rift zone
 | journal=[[Geophysical Research Letters]]
 | date=17 June 2015 | pages=4762–4769 | volume=42 |issue=12
 | bibcode=2015GeoRL..42.4762S |s2cid=16309185
 | doi=10.1002/2015GL064088
 | doi-access=free }}</ref>

<ref name="Strom1994">{{cite journal
 | last1=Strom |first1=Robert G.
 | last2=Schaber | first2=Gerald G.
 | last3=Dawson | first3=Douglas D.
 | title=The global resurfacing of Venus
 | journal=[[Journal of Geophysical Research]]
 | volume=99 | issue=E5 | pages=10899–10926 | date=25 May 1994
| doi=10.1029/94JE00388 |bibcode=1994JGR....9910899S
 |s2cid=127759323
 | url=https://zenodo.org/record/1231347
 | access-date=25 June 2019 | archive-date=16 September 2020 | archive-url=https://web.archive.org/web/20200916233329/https://zenodo.org/record/1231347
 | url-status=live }}</ref>

<ref name=Romeo_Turcotte_2018>{{cite journal
 | last1=Romeo | first1=I. | last2=Turcotte | first2=D. L.
 | title=The frequency-area distribution of volcanic units on Venus: Implications for planetary resurfacing
 | journal=Icarus | year=2009
 | volume=203 | issue=1 | pages=13–19
 | doi=10.1016/j.icarus.2009.03.036 | bibcode=2009Icar..203...13R
 | url=http://eprints.ucm.es/13279/1/Icarus_2009_1.pdf
 | access-date=15 December 2018 |archive-date=19 December 2019
| archive-url=https://web.archive.org/web/20191219010514/http://eprints.ucm.es/13279/1/Icarus_2009_1.pdf
 | url-status=live }}</ref>

<ref name=Herrick_Phillips_1993>{{cite journal
 | title=Effects of the Venusian atmosphere on incoming meteoroids and the impact crater population
 | last1=Herrick | first1=R. R. | last2=Phillips | first2=R. J.
 | journal=Icarus | year=1993
 | volume=112 | issue=1 | pages=253–281
 | doi=10.1006/icar.1994.1180 | bibcode=1994Icar..112..253H}}</ref>

<ref name=Morrison_Owens_2003>{{cite book
 | title=The Planetary System |edition=3rd
 | first1=David | last1=Morrison | first2=Tobias C. | last2=Owens
 | publisher=[[Benjamin Cummings]] | location=San Francisco
 | year=2003 | isbn=978-0-8053-8734-6}}</ref>

<ref name="goettel">{{cite conference
 | last1=Goettel | first1=K. A. | last2=Shields | first2=J. A.
 | last3=Decker | first3=D. A.
 | title=Density constraints on the composition of Venus
 | book-title=Proceedings of the Lunar and Planetary Science Conference
 | publisher=[[Pergamon Press]] | pages=1507–1516
 | location=Houston, TX | date=16–20 March 1981
 | bibcode=1982LPSC...12.1507G }}</ref>

<ref name=Faure_Mensing_2007>{{cite book
 | title=Introduction to planetary science: the geological perspective 
 | last1=Faure | first1=Gunter | last2=Mensing | first2=Teresa M.
 | date=2007 | page=201
 | series=Springer eBook collection
 | publisher=Springer |isbn=978-1-4020-5233-0
 | url=https://archive.org/details/introductiontopl00faur_709/
 | url-access=limited }}</ref>

<ref name=Dumoulin2017>{{cite journal
 | title=Tidal constraints on the interior of Venus
 | last1=Dumoulin | first1=C. | last2=Tobie | first2=G.
 | last3=Verhoeven | first3=O. | last4=Rosenblatt | first4=P.
 | last5=Rambaux | first5=N.
 | journal=Journal of Geophysical Research: Planets
 | volume=122 | issue=6 | pages=1338–1352 | date=June 2017
 | doi=10.1002/2016JE005249 | s2cid=134766723
 | bibcode=2017JGRE..122.1338D
 | url=https://hal.archives-ouvertes.fr/hal-02481364/file/Dumoulin17.pdf
 | access-date=3 May 2021 | archive-date=9 May 2020
| archive-url=https://web.archive.org/web/20200509223939/https://hal.archives-ouvertes.fr/hal-02481364/file/Dumoulin17.pdf
 | url-status=live }}</ref>

<ref name=Aitta_2016>{{cite journal
 | title=Venus' internal structure, temperature and core composition
 | last=Aitta | first=A.
 | journal=Icarus | date=April 2012
 | volume=218 | issue=2 | pages=967–974
 | doi=10.1016/j.icarus.2012.01.007 | bibcode=2012Icar..218..967A 
 | url=https://www.researchgate.net/publication/256719725
 | access-date=17 January 2016 | archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074425/https://www.researchgate.net/publication/256719725_Venus%27_internal_structure_temperature_and_core_composition
 | url-status=live }}</ref>

<ref name="O'Callaghan_2021">{{cite news
 | title=We've measured the size of Venus's planetary core for the first time
 | last1=O'Callaghan | first1=Jonathan
 | url=https://www.newscientist.com/article/2276218-weve-measured-the-size-of-venuss-planetary-core-for-the-first-time/
 | work=New Scientist | date=29 April 2021
| access-date=2 May 2021 | archive-date=2 May 2021
| archive-url=https://web.archive.org/web/20210502211510/https://www.newscientist.com/article/2276218-weve-measured-the-size-of-venuss-planetary-core-for-the-first-time/
 | url-status=live }}</ref>

<ref name=Nimmo_2002>{{cite journal
 | title=Crustal analysis of Venus from Magellan satellite observations at Atalanta Planitia, Beta Regio, and Thetis Regio
 | last=Nimmo | first=F.
 | journal=[[Geology (journal)|Geology]]
 | volume=30 | issue=11 | pages=987–990 | date=2002
 | doi=10.1130/0091-7613(2002)030<0987:WDVLAM>2.0.CO;2
 | issn=0091-7613 | bibcode=2002Geo....30..987N | s2cid=13293506
 }}</ref>

<ref name="Nimmo98">{{cite journal
 | title=Volcanism and Tectonics on Venus
 | last1=Nimmo | first1=F. | last2=McKenzie | first2=D.
 | journal=[[Annual Review of Earth and Planetary Sciences]]
 | volume=26 | issue=1 | pages=23–53 | date=1998
 | doi=10.1146/annurev.earth.26.1.23
 | bibcode=1998AREPS..26...23N | s2cid=862354
 }}</ref>

<ref name=Eroshenko_et_al_1969>{{cite journal
 |title=Nature of the Magnetic Field in the Neighborhood of Venus
 |author1=Dolginov, Sh. |author2=Eroshenko, E. G. |author3=Lewis, L.
 |journal=[[Cosmic Research]]
 |volume=7 |page=675 |date=September 1969
 |bibcode=1969CosRe...7..675D}}</ref>

<ref name=Kivelson_Russell_1995>{{cite book
 | last1=Kivelson | first1=G. M. | last2=Russell | first2=C. T.
 | title=Introduction to Space Physics
 | publisher=[[Cambridge University Press]]
 | date=1995 | isbn=978-0-521-45714-9 }}</ref>

<ref name=Luhmann_Russell_2006>{{cite book
 | title=Encyclopedia of Planetary Sciences
 | last1=Luhmann | first1=J. G. | last2=Russell | first2=C. T.
 | chapter-url=http://www-spc.igpp.ucla.edu/personnel/russell/papers/venus_mag/
 | chapter=Venus: Magnetic Field and Magnetosphere
 | publisher=[[Chapman and Hall]] | location=New York
 | editor1-last=Shirley | editor1-first=J. H.
 | editor2-last=Fainbridge | editor2-first=R. W.
 | pages=905–907 | year=1997
 | isbn=978-1-4020-4520-2
 | access-date=19 July 2006 | archive-date=14 July 2010
| archive-url=https://web.archive.org/web/20100714051425/http://www-spc.igpp.ucla.edu/personnel/russell/papers/venus_mag/
 | url-status=live }}</ref>

<ref name=Stevenson_2003>{{cite journal
 | title=Planetary magnetic fields
 | last=Stevenson | first=D. J. | date=15 March 2003
| journal=[[Earth and Planetary Science Letters]]
 | volume=208 | issue=1–2 | pages=1–11
 | doi=10.1016/S0012-821X(02)01126-3 | bibcode=2003E&PSL.208....1S
 | url=http://authors.library.caltech.edu/12373/1/STErpp83.pdf
 | access-date=6 November 2018 |archive-date=16 August 2017
| archive-url=https://web.archive.org/web/20170816033607/http://authors.library.caltech.edu/12373/1/STErpp83.pdf
 | url-status=live }}</ref>

<ref name="nimmo02">{{cite journal
 | title=Why does Venus lack a magnetic field?
 | first=Francis | last=Nimmo
 | journal=Geology | date=November 2002
 | volume=30 | issue=11 | pages=987–990
 | url=http://www2.ess.ucla.edu/~nimmo/website/paper25.pdf
 | doi=10.1130/0091-7613(2002)030<0987:WDVLAM>2.0.CO;2
 | issn=0091-7613 | bibcode=2002Geo....30..987N
 | access-date=28 June 2009 | archive-date=1 October 2018
| archive-url=https://web.archive.org/web/20181001172434/http://www2.ess.ucla.edu/~nimmo/website/paper25.pdf
 | url-status=live }}</ref>

<ref name=Konopliv_Yoder_1996>{{cite journal
 | last1=Konopliv | first1=A. S. | last2=Yoder | first2=C. F.
 | title=Venusian ''k''<sub>2</sub> tidal Love number from Magellan and PVO tracking data
 | journal=[[Geophysical Research Letters]]
 | volume=23 | issue=14 | pages=1857–1860 | year=1996
 | doi=10.1029/96GL01589 | bibcode=1996GeoRL..23.1857K }}</ref>

<ref name="nature450_7170_629">{{cite journal
 | title=Venus as a more Earth-like planet
 | last1=Svedhem | first1=Håkan | last2=Titov | first2=Dmitry V.
 | last3=Taylor | first3=Fredric W. | last4=Witasse | first4=Olivier
 | journal=Nature | date=November 2007
 | volume=450 | issue=7170 | pages=629–632
 | bibcode=2007Natur.450..629S | pmid=18046393
 | doi=10.1038/nature06432 | s2cid=1242297 }}</ref>

<ref name="O'Rourke_et_al_2019">{{cite conference
 | title=Prospects for an ancient dynamo and modern crustal remnant magnetism on Venus
 | last1=O'Rourke | first1=Joseph | last2=Gillmann | first2=Cedric
 | last3=Tackley | first3=Paul
 | conference=21st EGU General Assembly, EGU2019, Proceedings from the conference held 7–12 April 2019 in Vienna, Austria
 | id=18876 | date=April 2019
 | bibcode=2019EGUGA..2118876O }}</ref>

<ref name=Donahue_et_al_1982>{{cite journal
 | title=Venus Was Wet: A Measurement of the Ratio of Deuterium to Hydrogen
 | last1=Donahue | first1=T. M. | last2=Hoffman | first2=J. H.
 | last3=Hodges | first3=R. R. | last4=Watson | first4=A. J.
 | journal=Science | year=1982
 | volume=216 |issue=4546 | pages=630–633
 | issn=0036-8075 | doi=10.1126/science.216.4546.630
 | bibcode=1982Sci...216..630D | pmid=17783310 |s2cid=36740141
 }}</ref>

<ref name="psj_1_42">{{Cite journal
 | title=Could the Migration of Jupiter Have Accelerated the Atmospheric Evolution of Venus?
 | last1=Kane | first1=S. R. | last2=Vervoort | first2=P.
 | last3=Horner | first3=J. | last4=Pozuelos | first4=P. J.
 | journal=[[Planetary Science Journal]]
 | volume=1 | pages=42–51 | date=September 2020 | issue=2
 | doi=10.3847/PSJ/abae63 | doi-access=free
 | arxiv=2008.04927 | bibcode=2020PSJ.....1...42K }}</ref>

<ref name="MoreOrLess">{{cite web
 | title=BBC Radio 4—More or Less, Sugar, Outdoors Play and Planets
 | last1=Harford | first1=Tim
 | url=https://www.bbc.co.uk/programmes/m0001y9p
 | website=BBC | date=11 January 2019
| access-date=30 October 2019 | archive-date=12 January 2019
| archive-url=https://web.archive.org/web/20190112044935/https://www.bbc.co.uk/programmes/m0001y9p
 | url-status=live
 | quote=Oliver Hawkins, more or less alumnus and statistical legend, wrote some code for us, which calculated which planet was closest to the Earth on each day for the past 50 years, and then sent the results to [[David A. Rothery]], professor of planetary geosciences at the Open University. }}</ref>

<ref name=Solex11>{{cite web
 | title=Venus Close Approaches to Earth as predicted by Solex 11
 | url=http://home.surewest.net/kheider/astro/Solex-Venus.txt
 | archive-date=9 August 2012 | access-date=19 March 2009
| archive-url=https://web.archive.org/web/20120809051650/http://home.surewest.net/kheider/astro/Solex-Venus.txt
}} Numbers generated by [https://web.archive.org/web/20150918233453/http://chemistry.unina.it/~alvitagl/solex/ Solex]</ref>

<ref name="AIP Publishing 2019 p.">{{cite journal
 | title=Venus is not Earth's closest neighbour
 | journal=Physics Today | publisher=AIP Publishing
 | date=12 March 2019 | issue=3 | page=30593 | issn=1945-0699
 | doi=10.1063/pt.6.3.20190312a | bibcode=2019PhT..2019c0593. | s2cid=241077611 }}</ref>

<ref name="Petropoulos Longuski Bonfiglio 2000 pp. 776–783">{{cite journal
 | title=Trajectories to Jupiter via Gravity Assists from Venus, Earth, and Mars
 | last1=Petropoulos | first1=Anastassios E.
 | last2=Longuski | first2=James M. | last3=Bonfiglio | first3=Eugene P.
 | journal=Journal of Spacecraft and Rockets
 | publisher=American Institute of Aeronautics and Astronautics (AIAA)
 | volume=37 | issue=6 | year=2000 | pages=776–783
 | issn=0022-4650 | doi=10.2514/2.3650
 | bibcode=2000JSpRo..37..776P }}</ref>

<ref name="Taylor 2020">{{cite web
 | last=Taylor
 | first=Chris
 | title=Welcome to Cloud City: The case for going to Venus, not Mars
 | website=Mashable
 | date=9 July 2020
 | url=https://mashable.com/feature/venus-mars-space-exploration
 | access-date=21 October 2022
 | archive-date=21 October 2022
| archive-url=https://web.archive.org/web/20221021222622/https://mashable.com/feature/venus-mars-space-exploration
 | url-status=live
 }}</ref>

<ref name=IERS>{{cite web
 | title=IERS Conventions (2010) | publisher=IERS | page=19
 | editor-last1=Petit |editor-first1=Gérard
 | editor-last2=Luzum |editor-first2=Brian
 | url=https://www.iers.org/IERS/EN/Publications/TechnicalNotes/tn36.html
 | access-date=16 April 2021 | archive-date=30 September 2019
| archive-url=https://web.archive.org/web/20190930193512/https://www.iers.org/IERS/EN/Publications/TechnicalNotes/tn36.html
 | url-status=live }}</ref>

<ref name="Venus">{{cite encyclopedia
 | title=Venus | date=2016
 | last=Squyres | first=Steven W. | author-link=Steven W. Squyres
 | encyclopedia=Encyclopædia Britannica Online
 | url=http://www.britannica.com/EBchecked/topic/625665/Venus
 | access-date=7 January 2016 |archive-date=28 April 2014
| archive-url=https://web.archive.org/web/20140428174456/http://www.britannica.com/EBchecked/topic/625665/Venus
 | url-status=live }}</ref>

<ref name=Bakich_2000>{{cite book
 | chapter=Rotational velocity (equatorial)
 | chapter-url=https://books.google.com/books?id=PE99nOKjbXAC&pg=PA50
 | title=The Cambridge Planetary Handbook
 | page=50 | date=2000
 | publisher=Cambridge University Press
 | last=Bakich | first=Michael E.
 | isbn=978-0-521-63280-5
 | url=https://archive.org/details/cambridgeplaneta00baki/page/50
 | access-date=31 January 2023 }}</ref>

<ref name="slowing spin">{{cite web
 | title=Could Venus Be Shifting Gear?
 | date=10 February 2012 | series=Venus Express
 | publisher=European Space Agency
 | url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Could_Venus_be_shifting_gear
 | access-date=7 January 2016 | archive-date=24 January 2016
| archive-url=https://web.archive.org/web/20160124032008/http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Could_Venus_be_shifting_gear
 | url-status=live }}</ref>

<ref name="planetary-facts">{{cite web
 | title=Planetary Facts
 | publisher=[[The Planetary Society]]
 | url=http://www.planetary.org/explore/space-topics/compare/planetary-facts.html
 | access-date=20 January 2016 |archive-date=11 May 2012
| archive-url=https://web.archive.org/web/20120511011542/http://www.planetary.org/explore/space-topics/compare/planetary-facts.html
 | url-status=live }}</ref>

<ref name="compare">{{cite web
 | title=Space Topics: Compare the Planets
 | publisher=[[The Planetary Society]]
 | url=http://www.planetary.org/explore/topics/compare_the_planets/terrestrial.html
 | access-date=12 January 2016 | archive-date=18 February 2006
| archive-url=https://web.archive.org/web/20060218084852/http://planetary.org/explore/topics/compare_the_planets/terrestrial.html
}}</ref>

<ref name=Brunier_2002>{{cite book
 | title=Solar System Voyage
 | first=Serge | last=Brunier | author-link=Serge Brunier
 | publisher=Cambridge University Press
 | year=2002 | page=40
 | url=https://books.google.com/books?id=JkLxJOhEj-wC&pg=PA40
 | isbn=978-0-521-80724-1
 | translator-last=Dunlop | translator-first=Storm
 | access-date=17 September 2017 | archive-date=3 August 2020
| archive-url=https://web.archive.org/web/20200803144137/https://books.google.com/books?id=JkLxJOhEj-wC&pg=PA40
 | url-status=live }}</ref>

<ref name=Correia_et_al_2003>{{cite journal
 | last1=Correia | first1=Alexandre C. M. | last2=Laskar | first2=Jacques
 | last3=De Surgy | first3=Olivier Néron
 | title=Long-Term Evolution of the Spin of Venus, Part I: Theory
 | journal=Icarus | date=May 2003
 | volume=163 | issue=1 | pages=1–23
 | url=http://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus1.2002.pdf
 | doi=10.1016/S0019-1035(03)00042-3 | bibcode=2003Icar..163....1C
 | access-date=9 September 2006 | archive-date=27 September 2019
| archive-url=https://web.archive.org/web/20190927122047/https://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus1.2002.pdf
 | url-status=live }}</ref>

<ref name=Laskar_De_Surgy_2003>{{cite journal
 | title=Long-Term Evolution of the Spin of Venus, Part II: Numerical Simulations
 | last1=Laskar | first1=Jacques | last2=De Surgy | first2=Olivier Néron
 | journal=Icarus | year=2003
 | volume=163 |issue=1 |pages=24–45
 | doi=10.1016/S0019-1035(03)00043-5 | bibcode=2003Icar..163...24C
 | url=http://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus2.2002.pdf
 | access-date=9 September 2006 | archive-date=2 May 2019
| archive-url=https://web.archive.org/web/20190502225637/https://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus2.2002.pdf
 | url-status=live }}</ref>

<ref name=Gold_Soter_1969>{{cite journal
 | title=Atmospheric Tides and the Resonant Rotation of Venus
 | last1=Gold | first1=T. | last2=Soter | first2=S.
 | journal=Icarus | date=1969
 | volume=11 | issue=3 | pages=356–66
 | doi=10.1016/0019-1035(69)90068-2 | bibcode=1969Icar...11..356G}}</ref>

<ref name="apj2_230_L123">{{Cite journal
 | last1=Shapiro | first1=I. I. | last2=Campbell | first2=D. B.
 | last3=De Campli | first3=W. M.
 | title=Nonresonance Rotation of Venus
 | journal=[[Astrophysical Journal]]
 | volume=230 |pages=L123–L126 | date=June 1979
 | doi=10.1086/182975 | bibcode=1979ApJ...230L.123S| doi-access=free }}</ref>

<ref name="icarus202">{{cite journal
 | title=A Survey for Satellites of Venus
 | last1=Sheppard | first1=Scott S. | last2=Trujillo | first2=Chadwick A.
 | journal=Icarus | date=July 2009
 | volume=202 | issue=1 | pages=12–16
 | doi=10.1016/j.icarus.2009.02.008 | s2cid=15252548
 | bibcode=2009Icar..202...12S | arxiv=0906.2781 }}</ref>

<ref name=Mikkola_et_al_2004>{{cite journal
 | title=Asteroid 2002 VE68: A Quasi-Satellite of Venus
 | last1=Mikkola | first1=S. | last2=Brasser | first2=R.
 | last3=Wiegert | first3=P. | last4=Innanen | first4=K.
 | journal=[[Monthly Notices of the Royal Astronomical Society]]
 | volume=351 | issue=3 | page=L63 | date=July 2004
 | doi=10.1111/j.1365-2966.2004.07994.x | doi-access=free
 | bibcode=2004MNRAS.351L..63M }}</ref>

<ref name=Carlos_De_la_Fuente_Marcos_2012>{{cite journal
 | title=On the Dynamical Evolution of 2002 VE68
 | first1=Carlos | last1=De la Fuente Marcos | last2=De la Fuente Marcos | first2=Raúl
 | journal=[[Monthly Notices of the Royal Astronomical Society]]
 | volume=427 | issue=1 | pages=728–39 | date=November 2012
 | doi=10.1111/j.1365-2966.2012.21936.x | doi-access=free | s2cid=118535095
 | bibcode=2012MNRAS.427..728D | arxiv=1208.4444 }}</ref>

<ref name="dynamics">{{Cite journal
 | title=Asteroid 2012 XE133: A Transient Companion to Venus
 | first1=Carlos | last1=De la Fuente Marcos | last2=De la Fuente Marcos | first2=Raúl
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=432 | issue=2 | pages=886–93 | date=June 2013
 | doi=10.1093/mnras/stt454 | doi-access=free |arxiv=1303.3705
 | bibcode=2013MNRAS.432..886D | s2cid=118661720 }}</ref>

<ref name=Musser_2006>{{cite news
 | title=Double Impact May Explain Why Venus Has No Moon
 | last=Musser | first=George | date=10 October 2006
| journal=[[Scientific American]]
 | url=http://www.sciam.com/article.cfm?articleID=0008DCD1-0A66-152C-8A6683414B7F0000&ref=sciam
 | access-date=7 January 2016 |archive-date=26 September 2007
| archive-url=https://web.archive.org/web/20070926222658/http://www.sciam.com/article.cfm?articleID=0008DCD1-0A66-152C-8A6683414B7F0000&ref=sciam
 | url-status=live }}</ref>

<ref name=Tytell_2006>{{cite news
 | title=Why Doesn't Venus Have a Moon?
 | last=Tytell | first=David
 | journal=[[Sky & Telescope]] | date=10 October 2006
| url=http://www.skyandtelescope.com/astronomy-news/why-doesnt-venus-have-a-moon
 | access-date=7 January 2016 | archive-date=24 October 2016
| archive-url=https://archive.today/20161024145541/http://www.skyandtelescope.com/astronomy-news/why-doesnt-venus-have-a-moon
 | url-status=live }}</ref>

<ref name="Frazier 2021">{{cite web
 | title=NASA's Parker Solar Probe Sees Venus Orbital Dust Ring
 | last=Frazier
 | first=Sarah
 | website=NASA
 | date=16 April 2021
 | url=http://www.nasa.gov/feature/goddard/2021/nasa-s-parker-solar-probe-sees-venus-orbital-dust-ring-in-first-complete-view
 | access-date=21 January 2023
 | archive-date=22 August 2022
| archive-url=https://web.archive.org/web/20220822021758/https://www.nasa.gov/feature/goddard/2021/nasa-s-parker-solar-probe-sees-venus-orbital-dust-ring-in-first-complete-view/
 | url-status=live
 }}</ref>

<ref name="Garner 2019">{{cite web
 | title=What Scientists Found After Sifting Through Dust in the Solar System
 | last=Garner
 | first=Rob
 | website=NASA
 | date=12 March 2019
 | url=http://www.nasa.gov/feature/goddard/2019/what-scientists-found-after-sifting-through-dust-in-the-solar-system
 | access-date=21 January 2023
 | archive-date=1 January 2023
| archive-url=https://web.archive.org/web/20230101003613/https://www.nasa.gov/feature/goddard/2019/what-scientists-found-after-sifting-through-dust-in-the-solar-system/
 | url-status=live
 }}</ref>

<ref name="Rehm 2021">{{cite web
 | last=Rehm
 | first=Jeremy
 | title=Parker Solar Probe Captures First Complete View of Venus Orbital Dust Ring
 | website=JHUAPL
 | date=15 April 2021
 | url=https://www.jhuapl.edu/NewsStory/210415-Parker-Solar-Probe-sees-Venus-dust-ring/
 | access-date=21 January 2023
 | archive-date=21 January 2023
| archive-url=https://web.archive.org/web/20230121044857/https://www.jhuapl.edu/NewsStory/210415-Parker-Solar-Probe-sees-Venus-dust-ring/
 | url-status=live
 }}</ref>

<ref name=Dickinson_1998>{{cite book
 | last=Dickinson | first=Terrence
 | title=NightWatch: A Practical Guide to Viewing the Universe
 | date=1998 | publisher=Firefly Books | page=134
 | location=Buffalo, NY | isbn=978-1-55209-302-3
 | url=https://books.google.com/books?id=BaMBgoKPmjAC
 | access-date=12 January 2016 |archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074424/https://books.google.com/books?id=BaMBgoKPmjAC
 | url-status=live }}</ref>

<ref name=Flanders_2011>{{cite news
 | title=See Venus in Broad Daylight!
 | publisher=[[Sky & Telescope]]
 | first=Tony | last=Flanders | date=25 February 2011
| url=http://www.skyandtelescope.com/community/skyblog/observingblog/116925708.html
 | access-date=11 January 2016 | archive-date=11 September 2012
| archive-url=https://archive.today/20120911073404/http://www.skyandtelescope.com/community/skyblog/observingblog/116925708.html
  }}</ref>

<ref name="ephemeris">{{cite web
 | title=Venus: Twelve year planetary ephemeris, 1995–2006
 | last=Espenak | first=Fred | date=1996
 | work=NASA Reference Publication 1349
 | publisher=NASA/Goddard Space Flight Center
 | url=http://eclipse.gsfc.nasa.gov/TYPE/venus2.html#ve2006
 | access-date=20 June 2006 | archive-url=https://web.archive.org/web/20000817181616/http://sunearth.gsfc.nasa.gov/eclipse/TYPE/venus2.html
 | archive-date=17 August 2000 }}</ref>

<ref name=ASP_2021>{{cite web
 | title=Identifying UFOs | work=Night Sky Network
 | publisher=Astronomical Society of the Pacific
 | url=https://nightsky.jpl.nasa.gov/news-display.cfm?News_ID=597
 | access-date=10 April 2021 | archive-date=10 April 2021
| archive-url=https://web.archive.org/web/20210410182652/https://nightsky.jpl.nasa.gov/news-display.cfm?News_ID=597
 | url-status=live }}</ref>

<ref name=Chatfield_2015>{{cite web
 | title=The Solar System with the naked eye
 | last=Chatfield | first=Chris | year=2010
 | work=The Gallery of Natural Phenomena
 | url=http://www.phenomena.org.uk/page105/page44/page44.html
 | archive-date=13 June 2015 | access-date=19 April 2017
| archive-url=https://web.archive.org/web/20150613105426/http://www.phenomena.org.uk/page105/page44/page44.html
 | url-status=live }}</ref>

<ref name=Gaherty_2012>{{cite news
 | title=Planet Venus Visible in Daytime Sky Today: How to See It
 | last=Gaherty | first=Geoff
 | work=Space.com | date=26 March 2012
| url=http://www.space.com/15036-venus-daylight-skywatching-tips.html
 | access-date=19 April 2017 | archive-date=19 April 2017
| archive-url=https://web.archive.org/web/20170419193826/http://www.space.com/15036-venus-daylight-skywatching-tips.html
 | url-status=live }}</ref>

<ref name=Goines_1995>{{cite web
 | title=Inferential Evidence for the Pre-telescopic Sighting of the Crescent Venus
 | last=Goines |first=David Lance
 | date=18 October 1995 | website=Goines.net
 | url=http://www.goines.net/Writing/venus.html
 | archive-url=https://web.archive.org/web/20210504082630/http://www.goines.net/Writing/venus.html
 | archive-date=4 May 2021 | access-date=19 April 2017
| url-status=live }}</ref>

<ref name=Boyle_2016>{{cite web
 | title=Venus transit: A last-minute guide
 | last=Boyle | first=Alan
 | work=NBC News | date=5 June 2012
| url=http://cosmiclog.nbcnews.com/_news/2012/06/05/12056397-venus-transit-a-last-minute-guide
 | access-date=11 January 2016 | archive-date=18 June 2013
| archive-url=https://web.archive.org/web/20130618160933/http://cosmiclog.nbcnews.com/_news/2012/06/05/12056397-venus-transit-a-last-minute-guide
}}</ref>

<ref name=Espenak_2004>{{cite web
 | last=Espenak | first=Fred
 | title=Transits of Venus, Six Millennium Catalog: 2000 BCE to 4000 CE |work=Transits of the Sun
 | publisher=NASA | year=2004
 | url=http://eclipse.gsfc.nasa.gov/transit/catalogue/VenusCatalog.html
 | access-date=14 May 2009 | archive-date=19 March 2012
| archive-url=https://web.archive.org/web/20120319134106/http://eclipse.gsfc.nasa.gov/transit/catalogue/VenusCatalog.html
 | url-status=live }}</ref>

<ref name=Kollerstrom_1998>{{cite web
 | title=Horrocks and the Dawn of British Astronomy
 | last=Kollerstrom | first=Nicholas | year=1998
 | publisher=[[University College London]]
 | url=http://www.dioi.org/kn/birth.htm
 | access-date=11 May 2012 | archive-date=26 June 2013
| archive-url=https://web.archive.org/web/20130626235945/http://www.dioi.org/kn/birth.htm
 | url-status=live }}</ref>

<ref name=Hornsby_1771>{{cite journal
 | title=The quantity of the Sun's parallax, as deduced from the observations of the transit of Venus on June 3, 1769
 | last=Hornsby | first=T.
 | journal=Philosophical Transactions of the Royal Society
 | volume=61 | pages=574–579 | year=1771
 | doi=10.1098/rstl.1771.0054 | s2cid=186212060
 | url=http://gallica.bnf.fr/ark:/12148/bpt6k55866b/f617.chemindefer
 | access-date=8 January 2008 |archive-date=9 May 2019
| archive-url=https://web.archive.org/web/20190509181354/https://gallica.bnf.fr/ark:/12148/bpt6k55866b/f617.chemindefer
 | url-status=live | url-access=subscription
 }}</ref>

<ref name=Woolley_1969>{{cite journal
 | title=Captain Cook and the Transit of Venus of 1769
 | first=Richard | last=Woolley
 | journal=[[Notes and Records of the Royal Society of London]]
 | volume=24 | issue=1 | pages=19–32 | year=1969
 | doi=10.1098/rsnr.1969.0004 | issn=0035-9149
 | jstor=530738 | s2cid=59314888 }}</ref>

<ref name=Ottewel_2022>{{cite web
 | title=The 5 petals of Venus and its 8-year cycle
 | last1=Ottewell
 | first1=Guy
 | url=https://earthsky.org/astronomy-essentials/five-petals-of-venus/
 | website=EarthSky
 | date=7 January 2022
| access-date=17 March 2022
| archive-date=22 February 2022
| archive-url=https://web.archive.org/web/20220222154200/https://earthsky.org/astronomy-essentials/five-petals-of-venus/
 | url-status=live
 }}</ref>

<ref name=Baum_2000>{{cite journal
 | title=The enigmatic ashen light of Venus: an overview
 | last=Baum | first=R. M.
 | journal=[[Journal of the British Astronomical Association]]
 | volume=110 | page=325 | year=2000
 | bibcode=2000JBAA..110..325B}}</ref>

<ref name="Cooley">{{cite journal
 | last=Cooley | first=Jeffrey L.
 | title=Inana and Šukaletuda: A Sumerian Astral Myth
 | journal=KASKAL | volume=5 | pages=161–172
 | year=2008 | issn=1971-8608
 | url=https://www.academia.edu/1247599
 | access-date=28 December 2017 |archive-date=24 December 2019
| archive-url=https://web.archive.org/web/20191224105634/https://www.academia.edu/1247599
 | url-status=live }}</ref>

<ref name=Sachs_1974>{{cite journal
 | last=Sachs|first=A.
 | title=Babylonian Observational Astronomy
 | journal=Philosophical Transactions of the Royal Society of London
 | volume=276 | issue=1257 | pages=43–50 | year=1974
 | bibcode=1974RSPTA.276...43S | s2cid=121539390
 | doi=10.1098/rsta.1974.0008 }}</ref>

<ref name=Hobson_2009>{{cite thesis
 | title=The Exact Transmission of Texts in the First Millennium B.C.E.
 | first=Russell | last=Hobson
 | publisher=[[University of Sydney]], Department of Hebrew, Biblical and Jewish Studies
 | type=Ph.D. | year=2009
 | url=http://ses.library.usyd.edu.au/bitstream/2123/5404/1/r-hobson-2009-thesis.pdf
 | access-date=26 December 2015 | archive-date=29 February 2012
| archive-url=https://web.archive.org/web/20120229144338/http://ses.library.usyd.edu.au/bitstream/2123/5404/1/r-hobson-2009-thesis.pdf
 | url-status=live }}</ref>

<ref name=Heimpel_1982>{{cite journal
 | last=Heimpel | first=W. | year=1982
 | title=A catalogue of Near Eastern Venus deities
 | journal=Syro-Mesopotamian Studies
 | volume=4 | issue=3 | pages=9–22
 | publisher=Undena Publications }}</ref>

<ref name=Needham_1959>{{cite book
 | title=Mathematics and the Sciences of the Heavens and the Earth
 | first=Joseph | last=Needham | author-link=Joseph Needham
 | series=Science and Civilisation in China
 | volume=3 | year=1959 |page=398
 | publisher=Cambridge University Press
 | location=Cambridge | isbn=978-0-521-05801-8
 | bibcode=1959scc3.book.....N }}</ref>

<ref name=Pliny_1991>{{cite book
 | title=Natural History II:36–37
 | author=Pliny the Elder
 | translator-last1=Healy | translator-first1=John F. 
 | publisher=[[Penguin Books|Penguin]]
 | location=Harmondsworth, Middlesex, UK
 | year=1991 | pages=15–16 }}</ref>

<ref name=Berkert_1972>{{cite book
 | title=Lore and Science in Ancient Pythagoreanism 
 | publisher=[[Harvard University Press]]
 | first=Walter | last=Burkert
 | page=307 | year=1972 | isbn=978-0-674-53918-1
 | url=https://books.google.com/books?id=0qqp4Vk1zG0C&pg=PA307
 | access-date=28 December 2015 | archive-date=9 June 2016
| archive-url=https://web.archive.org/web/20160609174557/https://books.google.com/books?id=0qqp4Vk1zG0C&pg=PA307
 | url-status=live }}</ref>

<ref name=Dobbin_2002>{{cite journal
 | title=An Ironic Allusion at "Aeneid" 1.374
 | first=Robert | last=Dobbin
 | journal=Mnemosyne | series=Fourth series
 | volume=55 | issue=6 | year=2002 | pages=736–738
 | publisher=Brill | doi=10.1163/156852502320880285
 | jstor=4433390 }}</ref>

<ref name="Goldstein">{{cite journal
 | title=Theory and Observation in Medieval Astronomy
 | first=Bernard R. | last=Goldstein
 | journal=[[Isis (journal)|Isis]]
 | volume=63 | issue=1 | date=March 1972 | pages=39–47 [44]
 | doi=10.1086/350839 | s2cid=120700705
 | bibcode=1972Isis...63...39G }}</ref>

<ref name=Enc_Irnica>{{cite encyclopedia
 | title=AVICENNA viii. Mathematics and Physical Sciences
 | encyclopedia=Encyclopædia Iranica
 | url=http://www.iranicaonline.org/articles/avicenna-viii
 | access-date=4 March 2016 | archive-date=20 February 2020 | archive-url=https://web.archive.org/web/20200220161012/http://www.iranicaonline.org/articles/avicenna-viii
 | url-status=live }}</ref>

<ref name=Ansari_2002>{{cite conference
 | title=History of Oriental Astronomy
 | conference=Proceedings of the Joint Discussion-17 at the 23rd General Assembly of the International Astronomical Union, Organised by the Commission 41 (History of Astronomy), Held in Kyoto, 25–26 August 1997
 | series =  Astrophysics and Space Science Library
 | first=S. M. Razaullah | last=Ansari
 | publisher=[[Springer Science+Business Media]]
 | year=2002 | page=137
 | isbn=978-1-4020-0657-9 }}</ref>

<ref name="palmieri">{{cite journal
 | title=Galileo and the discovery of the phases of Venus
 | last=Palmieri | first=Paolo
 | journal=[[Journal for the History of Astronomy]]
 | year=2001 | volume=21 | issue=2 | pages=109–129
 | bibcode=2001JHA....32..109P | s2cid=117985979
 | doi=10.1177/002182860103200202 }}</ref>

<ref name="Fegley">{{cite book
 | last=Fegley Jr | first=B.
 | chapter=Venus | year=2003 | pages=487–507
 | publisher=Elsevier | title=Treatise on Geochemistry
 | editor1-first=Heinrich D. | editor1-last=Holland
 | editor2-first=Karl K. | editor2-last=Turekian
 | isbn=978-0-08-043751-4 }}</ref>

<ref name="Kollerstrom">{{cite journal
 | title=William Crabtree's Venus transit observation
 | last=Kollerstrom |first=Nicholas
 | journal=Proceedings IAU Colloquium No. 196
 | year=2004 | volume=2004 | pages=34–40
 | bibcode=2005tvnv.conf...34K | s2cid=162838538
 | doi=10.1017/S1743921305001249 | doi-access=free
 | url=http://www.dioi.org/kn/IAUVenus-Transit.pdf
 | access-date=10 May 2012 | archive-date=19 May 2016
| archive-url=https://web.archive.org/web/20160519082541/http://www.dioi.org/kn/IAUVenus-Transit.pdf
 | url-status=live }}</ref>

<ref name="Marov2004">{{cite conference
 | title=Mikhail Lomonosov and the discovery of the atmosphere of Venus during the 1761 transit
 | last=Marov |first=Mikhail Ya.
 | work=Transits of Venus: New Views of the Solar System and Galaxy, Proceedings of IAU Colloquium #196, held 7–11 June 2004 in Preston, U.K.
 | year=2004 | volume=2004 | pages=209–219
 | editor-first=D. W. | editor-last=Kurtz
 | publisher=Cambridge University Press
 | doi=10.1017/S1743921305001390 | doi-access=free
 | bibcode=2005tvnv.conf..209M }}</ref>

<ref name=Britannica>{{cite encyclopedia
 | encyclopedia=Encyclopædia Britannica Online
 | title=Mikhail Vasilyevich Lomonosov
 | url=http://www.britannica.com/eb/article-9048817/Mikhail-Vasilyevich-Lomonosov
 | access-date=12 July 2009 | archive-date=25 July 2008
| archive-url=https://web.archive.org/web/20080725172753/http://www.britannica.com/eb/article-9048817/Mikhail-Vasilyevich-Lomonosov
 | url-status=live }}</ref>

<ref name=Russell_1899>{{cite journal
 | title=The Atmosphere of Venus
 | last=Russell |first=H. N. | year=1899
 | journal=Astrophysical Journal
 | volume=9 | pages=284–299 | s2cid=123671250
 | doi=10.1086/140593 | bibcode=1899ApJ.....9..284R
 }}</ref>

<ref name=Hussey_1832>{{cite journal
 | title=On the Rotation of Venus
 | last=Hussey | first=T.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=2 | issue=11 | pages=78–126 | year=1832
 | bibcode=1832MNRAS...2...78H
 | doi=10.1093/mnras/2.11.78d | doi-access=free
 | url=https://zenodo.org/record/1431833
 | access-date=25 August 2019 |archive-date=11 July 2020
| archive-url=https://web.archive.org/web/20200711115811/https://zenodo.org/record/1431833
 | url-status=live }}</ref>

<ref name="Nemet-Nejat">{{cite book
 | last=Nemet-Nejat |first=Karen Rhea
 | title=Daily Life in Ancient Mesopotamia
 | publisher=Greenwood | isbn=978-0-313-29497-6 | page=203 | year=1998
 | url=https://archive.org/details/dailylifeinancie00neme/page/203
 | access-date=2 February 2023 }}</ref>

<ref name=Ross_1928>{{cite journal
 | title=Photographs of Venus
 | last=Ross | first=F. E.
 | journal=Astrophysical Journal
 | volume=68 | year=1928 | page=57
 | doi=10.1086/143130 | bibcode=1928ApJ....68...57R}}</ref>

<ref name=Slipher_1903>{{cite journal
 | title=A Spectrographic Investigation of the Rotation Velocity of Venus
 | last=Slipher | first=V. M.
 | journal=[[Astronomische Nachrichten]]
 | volume=163 | issue=3–4 | pages=35–52 | year=1903
 | bibcode=1903AN....163...35S |doi=10.1002/asna.19031630303
 | url=https://zenodo.org/record/1424793
 | access-date=4 May 2020 |archive-date=27 October 2020 | archive-url=https://web.archive.org/web/20201027040028/https://zenodo.org/record/1424793
 | url-status=live }}</ref>

<ref name=Martz_1934>{{cite journal
 | title=Venus and life
 | last=Martz | first=Edwin P. Jr.
 | journal=Popular Astronomy
 | volume=42 | page=165 | year=1934
 | bibcode=1934PA.....42..165M }}</ref>

<ref name=Goldstein_Carpenter_1963>{{cite journal
 | title=Rotation of Venus: Period Estimated from Radar Measurements
 | last1=Goldstein | first1=R. M. | last2=Carpenter | first2=R. L.
 | journal=Science
 | volume=139 | issue=3558 | pages=910–911 | year=1963
 | doi=10.1126/science.139.3558.910 | pmid=17743054
 | bibcode=1963Sci...139..910G | s2cid=21133097 }}</ref>

<ref name=Campbell_et_al_1976>{{cite journal
 | title=New radar image of Venus
 | last1=Campbell | first1=D. B. | last2=Dyce | first2=R. B.
 | last3=Pettengill | first3=G. H.
 | journal=Science | year=1976
 | volume=193 | issue=4258 | pages=1123–1124
 | doi=10.1126/science.193.4258.1123 | pmid=17792750
 | bibcode=1976Sci...193.1123C | s2cid=32590584 }}</ref>

<ref name="mitchell_1">{{cite web
 |title=Inventing The Interplanetary Probe
 | first=Don | last=Mitchell | date=2003
 | work=The Soviet Exploration of Venus
 | url=http://www.mentallandscape.com/V_OKB1.htm
 | access-date=27 December 2007 |archive-date=12 October 2018
| archive-url=https://web.archive.org/web/20181012053708/http://mentallandscape.com/V_OKB1.htm
 | url-status=live }}</ref>

<ref name=Mayer_et_al_1958>{{cite journal
 | title=Observations of Venus at 3.15-cm Wave Length
 | last1=Mayer | first1=C. H. | last2=McCullough | first2=T. P.
 | last3=Sloanaker | first3=R. M.
 | journal=The Astrophysical Journal
 | date=January 1958 | volume=127 | page=1
 | bibcode=1958ApJ...127....1M | doi=10.1086/146433 | doi-access=free }}</ref>

<ref name=NASA_1962>{{cite report
 | title=Mariner-Venus 1962 Final Project Report
 | author=Jet Propulsion Laboratory
 | publisher=NASA | date=1962 | version=SP-59 
 | url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005413_1966005413.pdf
 | access-date=7 July 2017 | archive-date=11 February 2014
| archive-url=https://web.archive.org/web/20140211144532/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005413_1966005413.pdf
 | url-status=live }}</ref>

<ref name="mitchell_2">{{cite web
 | title=Plumbing the Atmosphere of Venus
 | first=Don | last=Mitchell | date=2003
 | work=The Soviet Exploration of Venus
 | url=http://www.mentallandscape.com/V_Lavochkin1.htm
 | access-date=27 December 2007 | archive-date=30 September 2018 | archive-url=https://web.archive.org/web/20180930201301/http://mentallandscape.com/V_Lavochkin1.htm
 | url-status=live }}</ref>

<ref name=COSPAR_Group_VII_1969>{{cite conference
 | title=Report on the Activities of the COSPAR Working Group VII
 | page=94 | date=11–24 May 1969 | location=Prague, Czechoslovakia
 | book-title=Preliminary Report, COSPAR Twelfth Plenary Meeting and Tenth International Space Science Symposium
 | publisher=[[National Academy of Sciences]] }}</ref>

<ref name=Time_1971>{{cite magazine
 | title=Science: Onward from Venus
 | date=8 February 1971
| magazine=[[Time (magazine)|Time]]
 | url=http://www.time.com/time/magazine/article/0,9171,909834,00.html
 | access-date=2 January 2013 | archive-date=21 December 2008
| archive-url=https://web.archive.org/web/20081221214000/http://www.time.com/time/magazine/article/0,9171,909834,00.html
}}</ref>

<ref name=Colin_Hall_1977>{{cite journal
 | title=The Pioneer Venus Program
 | last1=Colin | first1=L. | last2=Hall | first2=C.
 | volume=20 | issue=3 | pages=283–306 | date=1977
 | journal=[[Space Science Reviews]]
 | bibcode=1977SSRv...20..283C | doi=10.1007/BF02186467
 | s2cid=122107496 }}</ref>

<ref name=Williams_2005>{{cite web
 | title=Pioneer Venus Project Information
 | first=David R. | last=Williams | date=6 January 2005
| publisher=NASA/Goddard Space Flight Center
 | url=http://nssdc.gsfc.nasa.gov/planetary/pioneer_venus.html
 | access-date=19 July 2009 |archive-date=15 May 2019
| archive-url=https://web.archive.org/web/20190515084212/https://nssdc.gsfc.nasa.gov/planetary/pioneer_venus.html
 | url-status=live }}</ref>

<ref name=Greeley_Batson_2007>{{cite book
 | last1=Greeley | first1=Ronald | author-link=Ronald Greeley
 | last2=Batson | first2=Raymond M.
 | title=Planetary Mapping
 | page=47 | date=2007 | isbn=978-0-521-03373-2
 | publisher=Cambridge University Press
 | url=https://books.google.com/books?id=ztodv66A1VsC&pg=PA47
 | access-date=19 July 2009 |archive-date=29 September 2021
| archive-url=https://web.archive.org/web/20210929074424/https://books.google.com/books?id=ztodv66A1VsC&pg=PA47
 | url-status=live }}</ref>

<ref name=Howell_2014>{{cite web
 | title=Venus Express Out Of Gas; Mission Concludes, Spacecraft On Death Watch
 | last=Howell | first=Elizabeth
 | website=[[Universe Today]] | date=16 December 2014
| url=https://www.universetoday.com/117312/venus-express-out-of-gas-mission-concludes-spacecraft-on-death-watch/
 | access-date=22 April 2021 | archive-date=22 April 2021
| archive-url=https://web.archive.org/web/20210422084103/https://www.universetoday.com/117312/venus-express-out-of-gas-mission-concludes-spacecraft-on-death-watch/
 | url-status=live }}</ref>

<ref name="Volume 7 of Mayan studies">{{cite book
 | title=The Book of Chumayel: The Counsel Book of the Yucatec Maya, 1539–1638
 | date=1899 |publisher=Richard Luxton
 | isbn=978-0-89412-244-6 | pages=6,194 }}</ref>

<ref name="Milbrath">{{Cite book
 | title=Star Gods of The Mayans: Astronomy in Art, Folklore, and Calendars
 | last=Milbrath | first=Susan | date=1999
 | publisher=University of Texas Press
 | location= Austin, TX
 | isbn= 978-0-292-79793-2 | pages=200–204, 383 }}</ref>

<ref name=De_Groot_1912>{{cite book
 | title=Religion in China: universism. a key to the study of Taoism and Confucianism
 | first=Jan Jakob Maria|last=De Groot
 | series=American lectures on the history of religions
 | volume=10 | page=300 | year=1912
 | publisher=G. P. Putnam's Sons
 | url=https://books.google.com/books?id=ZAaP7dyjCrAC&pg=PA300
 | access-date=8 January 2010 | archive-date=22 July 2011
| archive-url=https://web.archive.org/web/20110722005812/http://books.google.com/books?id=ZAaP7dyjCrAC&pg=PA300
 | url-status=live }}</ref>

<ref name=Crump_1992>{{cite book
 | title=The Japanese numbers game: the use and understanding of numbers in modern Japan
 | first=Thomas | last=Crump | year=1992
 | url=https://archive.org/details/japanesenumbersg00crum
 | url-access=limited
 | pages=[https://archive.org/details/japanesenumbersg00crum/page/n53 39]–40
 | publisher=Routledge | isbn=978-0-415-05609-0}}</ref>

<ref name=Hulbert_1909>{{cite book
 | first=Homer Bezaleel | last=Hulbert | year=1909
 | title=The passing of Korea
 | page=[https://archive.org/details/passingkorea01hulbgoog/page/n538 426]
 | publisher=Doubleday, Page & company
 | url=https://archive.org/details/passingkorea01hulbgoog
 | access-date=8 January 2010 }}</ref>

<ref name=VOER>{{Cite web
 | title=Sao Kim – VOER
 | url=https://voer.edu.vn/m/sao-kim/87903266
 | access-date=26 December 2022
 | website=Vietnam Open Educational Resources
 | archive-date=26 December 2022
| archive-url=https://web.archive.org/web/20221226003259/https://voer.edu.vn/m/sao-kim/87903266
 | url-status=live
 }}</ref>

<ref name="bhalla06">{{cite book
 | last=Bhalla | first=Prem P.
 | title=Hindu Rites, Rituals, Customs and Traditions: A to Z on the Hindu Way of Life
 | page=29 | date=2006 | publisher=Pustak Mahal
 | isbn=978-81-223-0902-7 }}</ref>

<ref name="behari_frawley03">{{cite book
 | title=Myths & Symbols of Vedic Astrology
 | last1=Behari | first1=Bepin | last2=Frawley | first2=David
 | date=2003 | edition=2nd | publisher=Lotus Press
 | isbn=978-0-940985-51-3 | pages=65–74 }}</ref>

<ref name="Green1992">{{cite book
 | title=Gods, Demons and Symbols of Ancient Mesopotamia: An Illustrated Dictionary
 | last1=Black | first1=Jeremy | first2=Anthony | last2=Green
 | publisher=The British Museum Press
 | year=1992 | isbn=978-0-7141-1705-8 |pages=108–109
 | url=https://books.google.com/books?id=05LXAAAAMAAJ&q=Inana
 | access-date=23 August 2020 |archive-date=20 November 2020
| archive-url=https://web.archive.org/web/20201120094829/https://books.google.com/books?id=05LXAAAAMAAJ&q=Inana
 | url-status=live }}</ref>

<ref name="Cooley2">{{cite journal
 | title=Inana and Šukaletuda: A Sumerian Astral Myth
 | last=Cooley | first=Jeffrey L.
 | journal=KASKAL
 | volume=5 | pages=163–164 | year=2008 | issn=1971-8608
 | url=https://www.academia.edu/1247599
 | access-date=28 December 2017 | archive-date=24 December 2019
| archive-url=https://web.archive.org/web/20191224105634/https://www.academia.edu/1247599
 | url-status=live }}</ref>

<ref name=Cattermole_Moore_1997>{{cite book
 | last1=Cattermole | first1=Peter John
 | last2=Moore | first2=Patrick
 | title=Atlas of Venus
 | year=1997 | page=9
 | publisher=Cambridge University Press
 | isbn=978-0-521-49652-0 }}</ref>

<ref name="EBLCM">{{Cite encyclopedia
 | title=Lucifer | date=24 January 2020
| encyclopedia=Encyclopædia Britannica Online
 | url=https://www.britannica.com/topic/Lucifer-classical-mythology
 | access-date=3 February 2023 | archive-date=24 January 2020
 | archive-url=https://web.archive.org/web/20200124092904/https://www.britannica.com/topic/Lucifer-classical-mythology }}</ref>

<ref name=Cicero>{{cite book
 | title=De Natura Deorum | date=12 September 2005
| first=Marcus Tullius | last=Cicero
 | url=https://www.gutenberg.org/ebooks/14988
 | access-date=3 February 2023 | archive-date=12 September 2005
 | archive-url=https://web.archive.org/web/20050912023013/http://oll.libertyfund.org/Texts/Cicero0070/NatureOfGods/HTMLs/0040_Pt02_Book1.html
}}.</ref>

<ref name=Atsma>{{cite web
 | title=Eospheros & Hespheros
 | first=Aaron J. | last=Atsma
 | website=Theoi.com
 | url=https://www.theoi.com/Titan/AsterEosphoros.html
 | access-date=15 January 2016 |archive-date=14 July 2019
| archive-url=https://web.archive.org/web/20190714105448/https://www.theoi.com/Titan/AsterEosphoros.html
 | url-status=live }}</ref>

<ref name=Sobel_2005>{{cite book
 | first=Dava | last=Sobel |author-link=Dava Sobel
 | title=The Planets | year=2005
 | publisher=[[Harper Publishing]]
 | pages=53–70 | isbn=978-0-14-200116-5
 | url=https://books.google.com/books?id=5KHuAAAAMAAJ }}</ref>

<ref name="miller">{{cite book
 | title=Venus | year=2003
 | first=Ron | last=Miller
 | publisher=Twenty-First Century Books
 | page=12 | isbn=978-0-7613-2359-4
}}</ref>

<ref name=Dick_2001>{{cite book
 | first=Steven | last=Dick | year=2001
 | title=Life on Other Worlds: The 20th-Century Extraterrestrial Life Debate
 | page=43 | publisher=Cambridge University Press
 | isbn=978-0-521-79912-6 }}</ref>

<ref name=Seed_2005>{{cite book
 | first=David | last=Seed | year=2005
 | title=A Companion to Science Fiction
 | pages=[https://archive.org/details/companiontoscien00seed/page/n151 134]–135
 | publisher=Blackwell Publishing
 | isbn=978-1-4051-1218-5
 | url=https://archive.org/details/companiontoscien00seed
 | access-date=3 February 2023
 | url-access=limited }}</ref>

<ref name="stearn1961">{{cite journal
 | first=William T. | last=Stearn
 | title=The Male and Female Symbols of Biology
 | journal=[[New Scientist]]
 | issue=248 | pages=412–413 | date=17 August 1961
| url=https://books.google.com/books?id=BJ5eFU5aRecC&pg=PA413
 | archive-url=https://web.archive.org/web/20211123202014/https://books.google.com/books?id=BJ5eFU5aRecC&pg=PA413
 | url-status=dead | archive-date=23 November 2021 }}</ref>

<ref name=Clark_2003>{{cite news
 | title=Acidic clouds of Venus could harbour life
 | work=New Scientist | date=26 September 2003
| first=Stuart | last=Clark
 | url=https://www.newscientist.com/article/dn2843-acidic-clouds-of-venus-could-harbour-life.html
 | access-date=30 December 2015 | archive-date=16 May 2015
| archive-url=https://web.archive.org/web/20150516203938/http://www.newscientist.com/article/dn2843-acidic-clouds-of-venus-could-harbour-life.html
 | url-status=live }}</ref>

<ref name=Redfern_2004>{{cite news
 | title=Venus clouds 'might harbour life'
 | last=Redfern | first=Martin | date=25 May 2004
| work=BBC News | access-date=30 December 2015
| url=http://news.bbc.co.uk/2/hi/3746583.stm
 | archive-date=16 September 2020
| archive-url=https://web.archive.org/web/20200916211157/http://news.bbc.co.uk/2/hi/3746583.stm
 | url-status=live}}</ref>

<ref name="Dartnell2015">{{cite journal
 | title=Constraints on a potential aerial biosphere on Venus: I. Cosmic rays
 | last1=Dartnell | first1=Lewis R. | last2=Nordheim | first2=Tom Andre
 | last3=Patel | first3=Manish R. | last4=Mason | first4=Jonathon P.
 | last5=Coates | first5=Andrew J. | last6=Jones | first6=Geraint H.
 | journal=Icarus | date=September 2015 | volume=257 | pages=396–405
 | doi=10.1016/j.icarus.2015.05.006 | bibcode=2015Icar..257..396D}}</ref>

<ref name=Sagan_Morowitz_1967>{{cite journal
 | last1=Sagan | first1=Carl | author-link1=Carl Sagan
 | last2=Morowitz | first2=Harold J. | author-link2=Harold J. Morowitz
 | title=Life in the Clouds of Venus?
 | journal=[[Nature (journal)|Nature]] | date=16 September 1967
| volume=215 | issue=5107 | pages=1259–1260
 | doi=10.1038/2161198a0|s2cid=11784372
 | url=https://www.nature.com/articles/2151259a0
 | access-date=17 September 2020 | archive-date=17 September 2020
| archive-url=https://web.archive.org/web/20200917080506/https://www.nature.com/articles/2151259a0
 | url-status=live | url-access=subscription}}</ref>

<ref name="TAJ-20190826">{{cite journal
 | title=Long-term Variations of Venus's 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope
 | last1=Lee | first1=Yeon Joo | last2=Jessup | first2=Kandis-Lea
 | last3=Perez-Hoyos | first3=Santiago | last4=Titov | first4=Dmitrij V.
 | last5=Lebonnois | first5=Sebastien | last6=Peralta | first6=Javier
 | last7=Horinouchi | first7=Takeshi | last8=Imamura | first8=Takeshi
 | last9=Limaye | first9=Sanjay | last10=Marcq | first10=Emmanuel
 | last11=Takagi | first11=Masahiro | last12=Yamazaki | first12=Atsushi
 | last13=Yamada | first13=Manabu | last14=Watanabe | first14=Shigeto
 | last15=Murakami | first15=Shin-ya | last16=Ogohara | first16=Kazunori
 | last17=McClintock | first17=William M. | last18=Holsclaw | first18=Gregory
 | last19=Roman | first19=Anthony
 | journal=The Astronomical Journal | date=26 August 2019
| volume=158 | issue=3 | page=126
 | arxiv=1907.09683 | bibcode=2019AJ....158..126L
 | s2cid=198179774 | doi=10.3847/1538-3881/ab3120
 | doi-access=free }}</ref>

<ref name="ES-20190903">{{cite news
 | title=Could microbes be affecting Venus' climate?
 | last=Anderson | first=Paul
 | date=3 September 2019 | work=[[Earth & Sky]]
 | url=https://earthsky.org/space/could-microbes-be-affecting-venus-climate
 | access-date=3 September 2019 |archive-date=3 September 2019
| archive-url=https://web.archive.org/web/20190903230026/https://earthsky.org/space/could-microbes-be-affecting-venus-climate
 | url-status=live }}</ref>

<ref name="stearn">{{cite journal
 | title=The Origin of the Male and Female Symbols of Biology
 | last=Stearn | first=William T.
 | journal=[[Taxon (journal)|Taxon]]
 | date=May 1968 | volume=11 | issue=4 | pages=109–113
 | doi=10.2307/1217734|jstor=1217734
 | s2cid=87030547
 }}</ref>

<ref name=Bains_et_al_2021>{{cite journal
 | title=Phosphine on Venus Cannot be Explained by Conventional Processes
 | first1=William | last1=Bains | first2=Janusz J. | last2=Petkowski
 | first3=Sara | last3=Seager | first4=Sukrit | last4=Ranjan
 | first5=Clara | last5=Sousa-Silva | first6=Paul B. | last6=Rimmer
 | first7=Zhuchang | last7=Zhan | first8=Jane S. | last8=Greaves
 | first9=Anita M. S. | last9=Richards
 | journal=Astrobiology | year=2021
 | volume=21 | issue=10 | pages=1277–1304
 | doi=10.1089/ast.2020.2352 | pmid=34283644 | arxiv=2009.06499
 | bibcode=2021AsBio..21.1277B|s2cid=221655331}}</ref>

<ref name=Perkins_2020>{{cite news
 | title=Curious and unexplained
 | first=Sid | last=Perkins
 | work=Science | date=14 September 2020
| url=https://www.science.org/content/article/curious-and-unexplained-gas-spotted-venus-s-atmosphere-also-spewed-microbes-earth
 | access-date=14 September 2020 | archive-date=14 September 2020
| archive-url=https://web.archive.org/web/20200914191458/https://www.sciencemag.org/news/2020/09/curious-and-unexplained-gas-spotted-venus-s-atmosphere-also-spewed-microbes-earth
 | url-status=live}}</ref>

<ref name=Seager_et_al_2020>{{cite journal
 | title=The Venusian Lower Atmosphere Haze as a Depot for Desiccated Microbial Life: A Proposed Life Cycle for Persistence of the Venusian Aerial Biosphere
 | first1=Sara | last1=Seager | first2=Janusz J. | last2=Petkowski
 | first3=Peter | last3=Gao | first4=William | last4=Bains
 | first5=Noelle C. | last5=Bryan | first6=Sukrit | last6=Ranjan
 | first7=Jane | last7=Greaves
 | journal=Astrobiology | date=14 September 2020
| volume=21 | issue=10 | pages=1206–1223
 | doi=10.1089/ast.2020.2244 | pmid=32787733
 | arxiv=2009.06474 | s2cid=221127006 }}</ref>

<ref name="Sample1">{{cite news
 | title=Scientists find gas linked to life in atmosphere of Venus
 | last1=Sample | first1=Ian
 | work=The Guardian | date=14 September 2020
| url=https://www.theguardian.com/science/2020/sep/14/scientists-find-gas-linked-to-life-in-atmosphere-of-venus
 | access-date=16 September 2020 | archive-date=5 February 2021
| archive-url=https://web.archive.org/web/20210205052135/https://www.theguardian.com/science/2020/sep/14/scientists-find-gas-linked-to-life-in-atmosphere-of-venus
 | url-status=live }}</ref>

<ref name=Kooser_2020>{{cite news
 | title=NASA chief calls for prioritizing Venus after surprise find hints at alien life
 | first=Amanda | last=Kooser
 | agency=CNet | date=14 September 2020
| url=https://www.cnet.com/news/nasa-chief-calls-for-prioritizing-venus-after-surprise-find-hints-at-alien-life/
 | access-date=14 September 2020
| archive-date=15 September 2020
| archive-url=https://web.archive.org/web/20200915075228/https://www.cnet.com/news/nasa-chief-calls-for-prioritizing-venus-after-surprise-find-hints-at-alien-life/
 | url-status=live}}</ref>

<ref name=Bridenstine_2020>{{cite tweet
 | user=JimBridenstine
 | number=1305598182571810822
 | date=14 September 2020
| title=Life on Venus? }}</ref>

<ref name="Plait1">{{cite web
 | title=Update: Life Above Hell? Serious doubt cast on Venus phosphine finding
 | last=Plait | first=Phil | date=26 October 2020
| website=Syfy.com | publisher=[[Syfy]]
 | url=https://www.syfy.com/syfywire/update-life-above-hell-serious-doubt-cast-on-venus-phosphine-finding
 | access-date=26 October 2020 |archive-date=29 October 2020
| archive-url=https://web.archive.org/web/20201029042824/https://www.syfy.com/syfywire/update-life-above-hell-serious-doubt-cast-on-venus-phosphine-finding
 | url-status=live }}</ref>

<ref name=Snellen_et_al_2020>{{cite journal
 | title=Re-analysis of the 267 GHz ALMA observations of Venus
 | last1=Snellen | first1=I. A. G. | last2=Guzman-Ramirez | first2=L.
 | last3=Hogerheijde | first3=M. R. | last4=Hygate | first4=A. P. S.
 | last5=van der Tak | first5=F. F. S.
 | journal=Astronomy & Astrophysics
 | volume=644 | pages=L2 | year=2020
 | doi=10.1051/0004-6361/202039717 | arxiv=2010.09761
 | bibcode=2020A&A...644L...2S | s2cid=224803085 }}</ref>

<ref name=Thompson2020>{{cite journal
 | title=The statistical reliability of 267-GHZ JCMT observations of Venus: No significant evidence for phosphine absorption
 | last=Thompson | first=M. A.
 | journal=Monthly Notices of the Royal Astronomical Society: Letters
 | volume=501 | pages=L18–L22 | year=2021
 | arxiv=2010.15188 | doi=10.1093/mnrasl/slaa187 | doi-access=free }}</ref>

<ref name=Cordiner_et_al_2021>{{cite journal
 | title=No evidence of phosphine in the atmosphere of Venus from independent analyses
 | last1=Villanueva | first1=Geronimo|last2=Cordiner|first2=Martin
 | last3=Irwin | first3=Patrick | first4=Imke | last4=de Pater
 | last5=Butler | first5=Bryan | last6=Gurwell | first6=Mark
 | last7=Milam | first7=Stefanie | last8=Nixon | first8=Conor
 | last9=Luszcz-Cook | first9=Statia | last10=Wilson | first10=Colin
 | last11=Kofman | first11=Vincent | last12=Liuzzi | first12=Giuliano
 | last13=Faggi | first13=Sara | last14=Fauchez | first14=Thomas
 | last15=Lippi | first15=Manuela | last16=Cosentino | first16=Richard
 | last17=Thelen | first17=Alexander | last18=Moullet | first18=Arielle
 | last19=Hartogh | first19=Paul | last20=Molter | first20=Edward
 | last21=Charnley | first21=Steve | last22=Arney | first22=Giada
 | last23=Mandell | first23=Avi | last24=Biver | first24=Nicolas
 | last25=Vandaele | first25=Ann | first26=Katherine | last26=de Kleer
 | last27=Kopparapu | first27=Ravi
 | journal=Nature Astronomy | year=2021
 | volume=5 | issue=7 | pages=631–635
 | doi=10.1038/s41550-021-01422-z | arxiv=2010.14305
 | bibcode=2021NatAs...5..631V | s2cid=236090264}}</ref>

<ref name=NRC_2006>{{cite book
 | title=Assessment of Planetary Protection Requirements for Venus Missions: Letter Report
 | author=National Research Council | date=2006
 | publisher=The National Academies Press
 | doi=10.17226/11584 | isbn=978-0-309-10150-9
 | url=http://www.nap.edu/openbook.php?record_id=11584
 | access-date=19 January 2021 | archive-date=17 July 2015
| archive-url=https://web.archive.org/web/20150717231529/http://www.nap.edu/openbook.php?record_id=11584
 | url-status=live }}</ref>

<ref name=Frazier_2021>{{cite web
 | title=Parker Solar Probe Primed for Fourth Venus Flyby
 | last=Frazier | first=Sarah
 | website=NASA | date=19 February 2021
| url=https://blogs.nasa.gov/parkersolarprobe/2021/02/19/parker-solar-probe-primed-for-fourth-venus-flyby/
 | access-date=22 April 2021 | archive-date=22 April 2021
| archive-url=https://web.archive.org/web/20210422095750/https://blogs.nasa.gov/parkersolarprobe/2021/02/19/parker-solar-probe-primed-for-fourth-venus-flyby/
 | url-status=live}}</ref>

<ref name="Kolirin1">{{cite news
 | last=Kolirin | first=Lianne
 | title=Venus is a Russian planet—say the Russians
 | work=CNN | date=18 September 2020
| url=https://edition.cnn.com/2020/09/18/world/venus-russian-planet-scn-scli-intl/index.html
 | access-date=21 September 2020 | archive-date=20 September 2020
| archive-url=https://web.archive.org/web/20200920211509/https://edition.cnn.com/2020/09/18/world/venus-russian-planet-scn-scli-intl/index.html
 | url-status=live }}</ref>

<ref name="Leman1">{{cite news
 | title=Venus Is a Russian Planet ... Says Russia
 | last=Leman | first=Jennifer
 | work=Popular Mechanics | date=18 September 2020
| url=https://www.popularmechanics.com/space/solar-system/a34041988/venus-russian-planet/
 | access-date=21 September 2020 | archive-date=20 September 2020
| archive-url=https://web.archive.org/web/20200920050620/https://www.popularmechanics.com/space/solar-system/a34041988/venus-russian-planet/
 | url-status=live }}</ref>

<ref name="Архив фантастики">{{cite web
 | title=Архив фантастики
 | website=Архив фантастики | language=ru
 | url=http://archivsf.narod.ru/1929/sergey_zhitomirsky/index.htm
 | access-date=2 September 2021 | archive-date=2 September 2021
| archive-url=https://web.archive.org/web/20210902230735/http://archivsf.narod.ru/1929/sergey_zhitomirsky/index.htm
 | url-status=live }}</ref>

<ref name="Inner Solar System 2015">{{cite book
 | title=Inner Solar System
 | editor-last=Badescu | editor-first=Viorel
 | editor-last2=Zacny | editor-first2=Kris
 | publisher=Springer International Publishing
 | year=2015 | isbn=978-3-319-19568-1
 | doi=10.1007/978-3-319-19569-8 }}</ref>

<ref name="Tickle 2015">{{cite web
 | title=A Look Into Whether Humans Should Try to Colonize Venus Instead of Mars
 | last=Tickle | first=Glen
 | website=Laughing Squid | date=5 March 2015
 | url=https://laughingsquid.com/a-look-into-whether-humans-should-try-to-colonise-venus-instead-of-mars/
 | access-date=1 September 2021 | archive-date=1 September 2021
| archive-url=https://web.archive.org/web/20210901191020/https://laughingsquid.com/a-look-into-whether-humans-should-try-to-colonise-venus-instead-of-mars/
 | url-status=live }}</ref>

<ref name=Warmflash_2017>{{cite web
 | title=Colonization of the Venusian Clouds: Is 'Surfacism' Clouding Our Judgement?
 | first=David | last=Warmflash
 | website=Vision Learning | date=14 March 2017
| url=https://www.visionlearning.com/blog/2017/03/14/colonization-venusian-clouds-surfacism-clouding-judgement/
 | access-date=20 September 2019 | archive-date=11 December 2019
| archive-url=https://web.archive.org/web/20191211122431/https://www.visionlearning.com/blog/2017/03/14/colonization-venusian-clouds-surfacism-clouding-judgement/
 | url-status=live }}</ref>

<ref name="Landis2003">{{cite conference
 | first=Geoffrey A. | last=Landis
 | book-title=AIP Conference Proceedings
 | title=Colonization of Venus
 | volume=654 | issue=1 | pages=1193–1198
 | doi=10.1063/1.1541418 | date=2003
 | url=http://link.aip.org/link/?APCPCS/654/1193/1
 | archive-url=https://archive.today/20120711103532/http://link.aip.org/link/?APCPCS/654/1193/1
 | archive-date=11 July 2012 | url-access=subscription
 }}</ref>
 
<ref name=Lawrence_2005>{{cite web
 | title=In Search of the Venusian Shadow
 | last=Lawrence | first=Pete | date=2005
 | website=Digitalsky.org.uk | access-date=13 June 2012
| url=http://www.digitalsky.org.uk/venus/shadow-of-venus.html
 | archive-url=https://web.archive.org/web/20120611003523/http://www.digitalsky.org.uk/venus/shadow-of-venus.html
 | archive-date=11 June 2012 }}</ref>

<ref name=Walker_2017>{{cite web
 | title=Viewing Venus in Broad Daylight
 | first=John | last=Walker
 | work=Fourmilab Switzerland
 | access-date=19 April 2017 | archive-date=29 March 2017
| url=http://www.fourmilab.ch/images/venus_daytime/
 | archive-url=https://web.archive.org/web/20170329024632/https://www.fourmilab.ch/images/venus_daytime/
 | url-status=live }}</ref>

<ref name="Jakosky">{{cite book
 | title=The New Solar System
 | last=Jakosky |first=Bruce M.
 | chapter=Atmospheres of the Terrestrial Planets
 | editor1-last=Beatty | editor1-first=J. Kelly
 | editor2-last=Petersen | editor2-first=Carolyn Collins
 | editor3-last=Chaikin | editor3-first=Andrew
 | edition=4th | date=1999 | pages=175–200
 | location=Boston |publisher=Sky Publishing
 | isbn=978-0-933346-86-4 |oclc=39464951}}</ref>

<ref name=Shiga_2007>{{cite web
 | title=Did Venus's ancient oceans incubate life?
 | first=David | last=Shiga
 | work=New Scientist | date=10 October 2007
| url=https://www.newscientist.com/article/dn12769-did-venuss-ancient-oceans-incubate-life.html
 | access-date=17 September 2017 |archive-date=24 March 2009
| archive-url=https://web.archive.org/web/20090324134332/https://www.newscientist.com/article/dn12769-did-venuss-ancient-oceans-incubate-life.html
 | url-status=live }}</ref>

<ref name=NASA_2019>{{Cite web
 | title=Moons
 | website=NASA Solar System Exploration
 | url=https://solarsystem.nasa.gov/moons/overview
 | access-date=26 August 2019 | archive-date=19 October 2019
| archive-url=https://web.archive.org/web/20191019012033/https://solarsystem.nasa.gov/moons/overview/
 | url-status=live}}</ref>

<ref name="Brammer 2020">{{cite web
 | last=Brammer
 | first=John Paul
 | title=Love/Hate Reads: 'Men Are From Mars, Women Are From Venus,' Revisited
 | website=VICE
 | date=10 February 2020
 | url=https://www.vice.com/en/article/n7j3nm/lovehate-reads-men-are-from-mars-women-are-from-venus-revisited
 | access-date=17 April 2023
 | archive-date=17 April 2023
| archive-url=https://web.archive.org/web/20230417234135/https://www.vice.com/en/article/n7j3nm/lovehate-reads-men-are-from-mars-women-are-from-venus-revisited
 | url-status=live
 }}</ref>

<ref name="Schott 2005 pp. 1509–1510">{{cite journal
 | title=Sex symbols ancient and modern: their origins and iconography on the pedigree
 | last=Schott | first=G. D.
 | journal=BMJ | date=22 December 2005
 | volume=331 | issue=7531 | pages=1509–1510
 | issn=0959-8138 | doi=10.1136/bmj.331.7531.1509
 | pmid=16373733 | pmc=1322246 }}</ref>

<ref name="Parker 1974">{{cite journal
 | title=Ancient Egyptian Astronomy
 | last=Parker | first=R. A.
 | journal=Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
 | publisher=The Royal Society | year=1974
 | volume=276 | issue=1257 | pages=51–65
 | issn=0080-4614 | jstor=74274 | doi=10.1098/rsta.1974.0009
 | bibcode=1974RSPTA.276...51P | s2cid=120565237 }}</ref>

<ref name="Quack 2019">{{cite book 
 | title=Oxford Research Encyclopedia of Planetary Science
 | last=Quack | first=Joachim Friedrich
 | chapter=The Planets in Ancient Egypt
 | publisher=Oxford University Press | date=23 May 2019
 | doi=10.1093/acrefore/9780190647926.013.61 | isbn=978-0-19-064792-6 }}</ref>

<ref name="Getty">{{cite web
 | title=Aphrodite and the Gods of Love: Roman Venus (Getty Villa Exhibitions)
 | website=Getty
 | url=https://www.getty.edu/art/exhibitions/aphrodite/venus.html
 | access-date=15 April 2023
 | archive-date=12 April 2023
| archive-url=https://web.archive.org/web/20230412080715/https://www.getty.edu/art/exhibitions/aphrodite/venus.html
 | url-status=live
 }}</ref>

<ref name=Whitney_1986>{{cite journal
 | title=The Skies of Vincent van Gogh
 | last=Whitney | first=Charles A.
 | journal=Art History|date=September 1986
 | volume=9| issue=3 | page=356
 | doi=10.1111/j.1467-8365.1986.tb00206.x }}</ref>

<ref name=Boime_1984>{{cite journal
 | last=Boime | first=Albert | author-link=Albert Boime
 | title=Van Gogh's ''Starry Night'': A History of Matter and a Matter of History
 | journal=Arts Magazine | date=December 1984 | page=88
 | url=http://www.albertboime.com/Articles/Dec1984.pdf
 | access-date=28 July 2018 | archive-date=23 November 2018
| archive-url=https://web.archive.org/web/20181123150057/http://www.albertboime.com/Articles/Dec1984.pdf
 | url-status=live }}</ref>

<ref name="u3r1a">{{cite journal | title=The deep atmosphere of Venus and the possible role of density-driven separation of CO2 and N2 | last1=Lebonnois | first1=Sebastien | last2=Schubert | first2=Gerald | journal=Nature Geoscience | publisher=Springer Science and Business Media LLC | volume=10 | issue=7 | date=26 June 2017 | pages=473–477 | issn=1752-0894 | doi=10.1038/ngeo2971 | bibcode=2017NatGe..10..473L | s2cid=133864520 | url=https://hal.archives-ouvertes.fr/hal-01635402/file/deepatm_persp_rev2.pdf | access-date=11 August 2023 | archive-date=4 May 2019 | archive-url=https://web.archive.org/web/20190504081028/https://hal.archives-ouvertes.fr/hal-01635402/file/deepatm_persp_rev2.pdf | url-status=live }}</ref>

<ref name="Ernst 2022">{{cite web
 | title=Venus was once more Earth-like, but climate change made it uninhabitable
 | last=Ernst
 | first=Richard
 | website=The Conversation
 | date=3 November 2022
 | url=http://theconversation.com/venus-was-once-more-earth-like-but-climate-change-made-it-uninhabitable-150445
 | access-date=21 April 2023
 | archive-date=21 April 2023
| archive-url=https://web.archive.org/web/20230421033219/http://theconversation.com/venus-was-once-more-earth-like-but-climate-change-made-it-uninhabitable-150445
 | url-status=live
 }}</ref>

<ref name="Way Del Genio 2020 p.">{{cite journal
 | title=Venusian Habitable Climate Scenarios: Modeling Venus Through Time and Applications to Slowly Rotating Venus-Like Exoplanets
 | last1=Way | first1=M. J. | last2=Del Genio | first2=Anthony D.
 | journal=Journal of Geophysical Research: Planets
 | publisher=American Geophysical Union (AGU)
 | volume=125 | issue=5 | year=2020
 | issn=2169-9097 | doi=10.1029/2019je006276
 | arxiv=2003.05704 | bibcode=2020JGRE..12506276W }}</ref>

<ref name="Way Del Genio Kiang Sohl 2016 pp. 8376–8383">{{cite journal
 | title=Was Venus the first habitable world of our solar system?
 | last1=Way | first1=M. J. | last2=Del Genio | first2=Anthony D.
 | last3=Kiang | first3=Nancy Y. | last4=Sohl | first4=Linda E.
 | last5=Grinspoon | first5=David H. | last6=Aleinov | first6=Igor
 | last7=Kelley | first7=Maxwell | last8=Clune | first8=Thomas
 | journal=Geophysical Research Letters
 | publisher=American Geophysical Union (AGU)
 | volume=43 | issue=16 | date=28 August 2016 | pages=8376–8383
 | issn=0094-8276 | doi=10.1002/2016gl069790 | pmid=28408771
 | pmc=5385710 | arxiv=1608.00706 | bibcode=2016GeoRL..43.8376W }}</ref>

<ref name="Steigerwald 2022">{{cite web
 | title=NASA Study: Massive Volcanism May Have Altered Ancient Venus' Climate
 | last=Steigerwald
 | first=Bill
 | website=NASA
 | date=2 November 2022
 | url=http://www.nasa.gov/feature/goddard/2022/venus-volcanic-climate-change
 | access-date=5 May 2023
 | archive-date=10 May 2023
| archive-url=https://web.archive.org/web/20230510213318/https://www.nasa.gov/feature/goddard/2022/venus-volcanic-climate-change/
 | url-status=live
 }}</ref>

<ref name="Tillman 2018">{{cite web
 | title=Venus' Atmosphere: Composition, Climate and Weather
 | last=Tillman
 | first=Nola Taylor
 | website=Space.com
 | date=18 October 2018
 | url=https://www.space.com/18527-venus-atmosphere.html
 | access-date=9 May 2023
 | archive-date=9 May 2023
| archive-url=https://web.archive.org/web/20230509122404/https://www.space.com/18527-venus-atmosphere.html
 | url-status=live
 }}</ref>

<ref name="Davis 2021">{{cite web
 | title=Why Is Venus So Bright? Here's How Its Proximity to Earth, Highly Reflected Clouds Affects It
 | last=Davis
 | first=Margaret
 | website=Science Times
 | date=14 July 2021
 | url=https://www.sciencetimes.com/articles/32272/20210714/why-venus-bright-heres-proximity-earth-highly-reflected-clouds-affects.htm
 | access-date=11 June 2023
 | archive-date=13 December 2022
| archive-url=https://web.archive.org/web/20221213203043/https://www.sciencetimes.com/articles/32272/20210714/why-venus-bright-heres-proximity-earth-highly-reflected-clouds-affects.htm
 | url-status=live
 }}</ref>

<ref name="ESA Blog Navigator – Navigator page for active ESA blogs 2012">{{cite web
 | title=Venus and Earth: worlds apart – Transit of Venus blog
 | website=ESA Blog Navigator – Navigator page for active ESA blogs
 | date=31 May 2012
 | url=https://blogs.esa.int/venustransit/2012/05/31/venus-and-earth-worlds-apart/
 | access-date=11 June 2023
 | archive-date=11 June 2023
| archive-url=https://web.archive.org/web/20230611201608/https://blogs.esa.int/venustransit/2012/05/31/venus-and-earth-worlds-apart/
 | url-status=live
 }}</ref>

<ref name=sci_news_1976>{{cite journal
 | title=The Unveiling of Venus: Hot and Stifling
 | journal=Science News | date=19 June 1976 
 | volume=109 | issue=25 | pages=388–389
 | jstor=3960800 | doi=10.2307/3960800
 | quote=100 watts per square meter ... 14,000 lux ... corresponds to ... daytime with overcast clouds }}</ref>

}}

== External links ==
{{Wikisourcecat}}
{{Sister project links|commonscat=Venus (planet)}}
* [https://web.archive.org/web/20150906034051/http://solarsystem.nasa.gov/planets/venus Venus profile] at NASA's Solar System Exploration site
* [http://nssdc.gsfc.nasa.gov/planetary/planets/venuspage.html Missions to Venus] and [http://nssdc.gsfc.nasa.gov/imgcat/thumbnail_pages/venus_thumbnails.html Image catalogue] at the [[National Space Science Data Center]]
* [http://www.mentallandscape.com/V_Venus.htm Soviet Exploration of Venus] and [http://www.mentallandscape.com/C_CatalogVenus.htm Image catalogue] at Mentallandscape.com
* [https://web.archive.org/web/20151015045714/http://www.strykfoto.org/venera.htm Image catalogue from the Venera missions]
* [http://www.nineplanets.org/venus.html Venus page] at ''[[The Nine Planets]]''
* [http://eclipse.gsfc.nasa.gov/transit/catalogue/VenusCatalog.html Transits of Venus] {{Webarchive|url=https://web.archive.org/web/20120319134106/http://eclipse.gsfc.nasa.gov/transit/catalogue/VenusCatalog.html |date=19 March 2012 }} at NASA.gov
* [http://www.geody.com/?world=venus Geody Venus], a search engine for surface features
* [https://gravitysimulator.org/solar-system/pentagram-of-venus Interactive 3D gravity simulation of the pentagram that the orbit of Venus traces when Earth is held fixed at the centre of the coordinate system]

=== Cartographic resources ===
* [https://web.archive.org/web/20071005184007/http://www.mapaplanet.org/explorer/venus.html Map-a-Planet: Venus] by the [[U.S. Geological Survey]]
* [https://web.archive.org/web/20160112001040/http://planetarynames.wr.usgs.gov/Page/VENUS/target Gazetteer of Planetary Nomenclature: Venus] by the [[International Astronomical Union]]
* [http://www.lpi.usra.edu/resources/vc/vchome.shtml Venus crater database] by the [[Lunar and Planetary Institute]]
* [http://planetologia.elte.hu/venusz-terkep-elte-ttk-kavucs.pdf Map of Venus] by [[Eötvös Loránd University]]
* [https://www.google.com/maps/space/venus/@33.5623476,-46.1493481,7057278m/data=!3m1!1e3 Google Venus 3D], interactive map of the planet

{{Venus}}
{{Solar System}}
{{Venus spacecraft}}
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[[Category:Venus| ]]
[[Category:Planets of the Solar System]]
[[Category:Terrestrial planets]]
[[Category:Astronomical objects known since antiquity]]