Wikipedia talk:WikiProject Astronomical objects

Nice. Me likes. However it might be easier to read if there were some type of fill color for the headings. Or was that you idea all along? I guess it wouldn't be too hard to assign colors to each plant/moon system. Earth (green perhaps), Mars (obvious), Jupiter (orange would work nice), Saturn (yellow maybe?), Uranus (lightblue), Neptune (blue), pluto (gray). Just some random thoughts, do with them what you see fit. --mav

Yeah, I was wondering about that. Perhaps I could classify bodies by their general composition? Rocky bodies brown or maybe grey, icy ones cyan, gas ones yellow? That way the color gives a little "at a glance" summary information. Only downside is that the vast majority of objects would be rocky or icy, with only four gassy ones, so that doesn't leave a lot of variety. Bryan Derksen

I would change the word moons to satelites. - fonzy

Second that. As for the colours, they are nice, but since they are only one of each kind, it's not really identifying, like with the Elements or Tree of Life pages.

Some further notes:

maybe we can make another template for stars/constellations?
the current planet articles use perhelion and aphelion iso pericentron and apocentron (are these really the same?)
use less scientific terms, or at least explain them in a link (lithosphere f.e.)

Jeronimo

"perihelion" means "closest approach to the Sun", which isn't correct for moons. "perigee" means "closest approach to Earth", which would only be useful for Earth's moon. I don't know what the corresponding terms for the various other planets would be. So I went with "pericentron", which means "closest approach to the center" and is the generic term for such; see orbit (I'll make pericentron and apocentron into redirects once this template is finalized, of course). Bryan Derksen

I see. I suppose you could go for the appropriate names in the appriopriate articles. So use -helion for planets, -centron for moons, possibly -gee for "our" moon. No need to have all tables exactly the same. Jeronimo

Good idea, added to the guidelines. :) Bryan Derksen

What your saying makes no sence too me :-s - fonzy, that also gives me an idea have a link to a simpler form of the table for younger children etc.

Explanations of the terms can be found in orbit, perhaps that article could be edited to be a bit clearer.

Just a related question: in the solar system articles, asteroids an comets are present as if they're part of the system. However, asteroids and comets are not (I assume) limited to the solar system. Shouldn't they be presented in a more general way, and listing the proper names of the belts of asteroids (which have escaped me for the moment)? Jeronimo

from what i know some orbit are sun hence are part of our system :_s i'm not a great astronomer though. - fonzy

It is almost certain that there are asteroids and comets orbiting other stars, and possibly in interstellar space as well. However, none have ever been detected as far as I am aware, and it will be a very long time before we're able to see that well (we just started being able to detect larger-than-Jupiter extrasolar planets a few years back). The articles should mention this possibility, but there isn't much else to say on the subject right now I suspect. Bryan Derksen

Guess you're right. Still, it may be better to say Asteroid belt at the bottom of the "Solar System" articles than simply Asteroids. Jeronimo

Ah, I see; I didn't know that was the specific asteroid link you were talking about. Hm... You're probably right, but I hesitate to change the link from a nice hefty article like asteroids to a one-line stub like asteroid belt that probably won't grow a whole lot larger. I guess I'll have to think about how to beef it up after I finish with these factsheet tables. Bryan Derksen

Okay, here's a question I'm currently pondering. Should the lithospheric composition of a body be broken down by element or by compound? ie, for an icy body, would it be best to list it as 50% water ice, or as 40% oxygen and 10% hydrogen (numbers pulled out of thin air)? I haven't searched around yet to see which manner of breakdown is more common in the astronomical resources yet, so it may simply come down to availability of source information. Bryan Derksen

BTW, would it be interesting to list in which direction the planets rotate? I think Venus is a retrograde planet, and there may be some moons that have the same property (?). Jeronimo

Triton (moon) also has that property, in fact it orbits retrograde as well. And Uranus (planet) also rotates retrograde, from a certain point of view. This can be indicated easily enough by just adding a minus sign to the duration; that's how I did it in Neptune (planet)'s moon summary table. Alternately, an axial tilt of more than 90° indicates retrograde rotation. Or, more explicitly, one could just add "(retrograde)" after the rotation period. That will possibly make the table wider, though, so I'd rather go with the negative sign. Fortunately, there aren't a lot of planets where this is an issue, so it can be worked out on a case-by-case basis what to do. Bryan Derksen

RE:surface temprature should it be celsius of kelvin? - fonzy Also before we added the table to artciles, lets be 100% shore its what we need. tehr wise it'll be like the wikiprodject countries where there are some tables with older layouts and some with newere ones.

I think using Celsius (though not the SI standard) would be more useful. Not many people even know the Kelvin scale, let alone they know how much 100 K is.

Heh, edit conflict. Here's what I'd written in response to fonzy: "I considered Kelvin, and decided to go with Celcius for two main reasons: first and foremost, it's more familiar and intuitive to most people (not counting Americans :), and second it's trivially easy to convert to Kelvin if necessary just by adding 273.15. But the conversion can go either way, so that second point isn't really important. Also, the element factsheets already work in Kelvin. Hm... I'll think about that some more. Anyone else have an opinion or other thoughts on this matter?"

I think the only thing making me hesitate from committing to Celsius at this point is that the element tables use Kelvin, but since we both brought up peoples' general familiarity with Celsius I think I'm leaning in that direction now. Bryan Derksen

Another idea I had, which I think would be really cool, is to add a simplified overview of the solar system as an image under the table title, and highlight the discussed planet. Moons could have something similar, showing their position around the planet. But I realise this is quite advanced. Jeronimo

-not really just need a person good at computer graphics - fonzy

Fortunately, I fiddle around with raytracing (POVRay program) occasionally as a hobby, and there's a site out there somewhere which has "skins" for all the planets and some of the moons. I should be able to whip up decent original graphics if need be, especially since most of the planets and moons would be pretty small and low-res in such images. I could even do animations pretty easily, though I'll have to read up on some of the maths involved.

But I think I'd like to think about that later, after I finish with the tables. :) Bryan Derksen

I vote for simply breaking down composition by compound and link each of those compounds to articles and then state and link the elements in the compound articles. Compounds have emergent properties that are oftentimes far different than their bits and pieces so I don't think it would be too useful to list the elements. Kelvin should be used instead of celcius because this is the SI standard and is used a great deal in astronomy. Kelvin is also always positive values and tells you far more useful information about space objects -- it is a measure of the average heat content of the body. Celcius also has its 0 and 100 based on the melting and boiling points of H₂O at standard pressure -- which is only found on Earth at sea level. Celcius therefore has limited utility. However, Kelvin should be linked and conversion factors placed on that page (just like with the element tables). I also like the idea of simply using a negative sign to indicate retrograde motion however this will be non-obvious to the vast majority of our visitors so I suggest we sublink retrograde under the minus sign. Then a person viewing the table could simply pass their mouse pointer over the link and presto! The word "retrograde" pops up in a mouse-over text box. Then if they need additional info they can click through (this is similar to the link; kJ/mol in the elements table). --mav

Good advice and ideas, all. And if all else fails, there may be room in the data column to have both Kelvin and Celsius, with Celsius in brackets. I imagine the table cells containing distance information will get somewhat large (in fact, it may be prudent to remove the AU parentheticals to keep the width down). As an experiment, I'm going to do up a planet with this table shortly to see how it looks with real data in it. Bryan Derksen

Also maybe next to the body name put the astronomical symbol for it (if its got one) - fonzy

As for the proposed colours, I have some different ones:

rocky: grey - that's the colour most people associate rocks with
ice: white - that's the colour of water ice (I know there are others)
gas: lightblue (as it is)
stars: yellow

I propose to use the real predefined HTML values for these. Jeronimo

I don't think white makes a good header color, since the default background color on most browsers is white; there'd be nothing to distinguish it. As for the grey, that was actally my first thought for rocky bodies so I'm game. Bryan Derksen

Yes, so the table is in fact transparent, that shouldn't really matter? Well, I guess it's just personal preferences here, so it doesn't really matter. I would however really prefer to use "color="yellow" " in stead of this one for the stars. Jeronimo

I think we will have to create a completel different table for stars. - fonzy

I just added a filled-out copy of the table to Venus (planet) as a "live" example to work with. As I had suspected, the (AU) information in the orbital radius cells added a lot of width to the table, so I'm going to take those out. Also, I couldn't find a convenient source of lithospheric composition, so I temporarily removed that from Venus' table. I'll put it back once I find a source. Bryan Derksen

The format of this table seems to have stabilized, there haven't been any new points raised in a few days now. I think the only outstanding issue is whether to go with pink or grey for the terrestrial planets (and maybe change the ice planet color, too). If there are no further problems or suggestions, then, I think I'll probably pick one of those colors and then start creating these factsheet tables in various articles around thrusday. Bryan Derksen 16:07 Aug 20, 2002 (PDT)

Oh, I have one: over on the Venus article the parenthetical (Gs) for gravity and (atm.) for atmospheric pressure are now the width-determining extras. It might be a good idea to just get rid of those and stick with the SI units, in the interest of saving a little more space. Bryan Derksen

Before we go too crazy about adding the table to many articles we may want to consider adding images to the top of the table of the bodies being described. This seems to work very well for the organism articles and saves valuable horizontal area. Another thing to consider is somehow tweaking the table to more distinctively distinguish planets from moons. Perhaps this can be done by having planets have a wider (or otherwise different) table border. The countries' template was applied way too fast after initial creation and the result now is that there a number of countries with a format that is not in sync with the current (hopefully mostly final) table and heading format. --mav