Wikipedia talk:WikiProject Astronomical objects/Archive 1

General
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&deg; 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


 * No problem. I've deliberately been adding the tables very slowly, both because I don't have a lot of time and to give room for ideas to show up thanks to wider exposure. So far there's only a table on Mercury (planet), Venus (planet), Earth, Mars (planet), Luna and Phobos (moon). I'll respond to your specific suggestions tonight, when I get home from work. Bryan Derksen

I don't think adding the templates right away will hurt. The application of the country template has led to a lot of changes and different versions around, but it has also attracted more people to the discussion as when we were only working at the Netherlands article, and they have brought good additions or at least discussion. Since there is no rule for a fixed structure among articles in a group at Wikipedia, it's not a problem if the now highly structured country articles have some minor differences in style and layout with other country articles. It will eventually be fixed.

Also, I think its impossible to agree upon a template that will never change. If somebody thinks the Flora or Fauna in a country deserve a special paragraph or that the national telephone prefix should be in the table, the template may be changed. And if man starts landing on other bodies than earth and the moon, we may want to add a table entry: man set foot on: (date), etc. Even if nothing would change, most objects in a group do not all have the same properties: not all moons have an atmosphere, not all countries have a capital city (or more than one), etc.

The only thing that should be taken care of when there is at least a basic form of a template is that nobody starts to modify the template at will (well, everybody can do what he/she wants of course), but rather should make a proposal at the page where the template is maintained. Right now, this is mostly done by the originators of the templates, who "guard" the templated pages. Jeronimo

I think a Table Row saying Discoverd by... is needed. If its say Jupiter right unknown etc. If it was discovered by a satelite (Voyager 1/2) rigth that down - fonzy.


 * I don't think it is needed and frankly looks very out of place along with the physical and chemical data. Who discovered the body and where is something that is best covered in a history section. But I will let Bryan decide since this is his baby. --mav

I think it is needed maybe put it somewhere else in the table. Bt ts good quick reference. - fonzy


 * Hm... an interesting idea, and right now I'm not really sure which way I think is best. On the one hand, every item in the table describes purely physical qualities of the body in question except for the discovery items. Also, five planets and one moon don't have discoverers or discovery dates, at least not ones recorded by history; those rows should be omitted from those tables. The "atmospheric composition" section is going to be omitted from a lot of the outer solar system moons, and the lithospheric composition thing has been omitted everywhere because I can't find a good source for it, but I'd prefer to keep such omissions to a minimum in order to make the table as consistent as possible. Tough decision. I'll think about it some more; I've been adding tables at a pretty slow rate, so there's no rush to finalize anything yet. Bryan 01:42 Sep 26, 2002 (UTC)

I do realise that some planets were discoverd bt the aceints and its unkwnown who discovered them. But you can just ommit it or right unknown or put earliest recording. - fonzy


 * Yeah, I think I'll probably go with that. Bryan 13:23 Sep 26, 2002 (UTC)

I have added it to Phobos and Deimos - fonzy

about the photos. I am not really shore about thsi. Should we move the photo on to the top of table. Or have a standard place for it. - fonzy


 * I'd suggest not, since there's going to be all sorts of different photos available for these objects (or in the case of some of the outer planet moons, none except for a pixel-wide streak). If we leave the photos to the main body of the article, then there's a lot more flexibility. The table also isn't as tall that way, allowing the layout of the article to adapt better to various browsers. I'm not wedded to the idea, though, so if anyone feels strongly about adding pictures to the table I won't stop it. Bryan 18:36 Sep 28, 2002 (UTC)

Well what i really meant or wnat is som,e basic standard. Standard size,type of picture and a standard placement. - fonzy


 * Back when I was adding a bunch of planet photos, I used the general standard of having a thumbnail with a maximum dimension of 200 pixels and centering it in the page with the caption underneath. But I didn't stick to that if there were some reason not to. Bryan 18:44 Sep 28, 2002 (UTC)

I'll jsut have a test go at 1 or 2 of them on postiing pictures etc. - fonzy


 * Something you might want to try is enclosing the image in this:
 * Image
 * instead of using a single-cell table. It's a much tidier way to align images, and better style. Bryan 18:55 Sep 28, 2002 (UTC)

ok I'll try that. but do you think the layout is better iwth having image on the left?


 * Yup, the only reason "right" was in that sample code is because I cut and pasted it from Smiley. Bryan 18:57 Sep 28, 2002 (UTC)

Now thats sorted should we decide on re organizeng how the article is written.? - fonzy

I'm a little dissatisfied with it, actually. Where did the caption and the link to the larger version of the image go? I preferred the old layout over the current one. Bryan 19:15 Sep 28, 2002 (UTC)

the caprion went into teh image page. I just think a standard shoudl be put down as there seems to be none for the images, or atcual article on the planets. - fonzy What do you suggest? - fonzy


 * If there is a standard for images, I think it should be very flexible since the sorts of pictures that are available for planets vary quite a lot. I think the captions are important, other than that one should use whatever images seem appropriate to the particular article. Bryan

You see I like having things the same in a standard way, maybe its because of my AS. But I really think there should be a standard article. = fonzy altough its onyl you and me talking here. and its abit hard to judge withe 2 ppl.


 * Yeah, perhaps we should find some other talk: page to discuss the planet articles in general. This one's focus is just the factsheet table. Bryan

I have just taken out from the library the 2000 Cambridge Planetary Handbook. It is packed with tons of lists of numbers for the various planets and moons; I'm going to probably go on a massive factsheet binge sometime in the next few days. Before I do so, however, I'm considering tweaking the factsheet a little. A couple of ideas I'm kicking around:


 * temperature range as well as mean temperature
 * For some of the moons and planets, this is quite significant. Unfortunately, the book only lists temperature ranges for the planets, so some additional digging will be necessary to complete all factsheets.


 * eccentricity instead of peri/apoapsis
 * All of the major sources of information I've found about the orbits of moons only lists eccentricity, and this book also lists error ranges for eccentricity which would be a pain to translate into peri/apoapsis. Also, it saves space, reducing two rows to just one without losing any information.


 * Albedo
 * It's listed in the book for almost all the moons, so why not?

Any thoughts or feelings on these additions? I'll go through and update all the existing factsheets myself, so no extra work for anyone. :) Bryan


 * Sounds OK. However, I think having a temperature range is much more informative than an average - in fact, we should have all. Also, make a link to albedo, it's not a common term. Jeronimo


 * Yeah, I'd been planning to list it as "max/avg/min". That way I can still fit it all on one "temperature" row still and hopefully save some space. Also, I was planning to look up the formula for figuring out peri/apoapsis from mean radius and eccentricity, and put that at elliptical orbit; that way I can have a link to that as well. I don't suppose anyone knows it offhand? Bryan


 * Maybe the formula at eccentricity is of use (haven't checked)? Jeronimo


 * Unfortunately, I don't think it is; it allows you to find the eccentricity of an ellipse given its semimajor and semiminor axes, and what I need is to be able to go from a mean radius and an eccentricity to a closest-approach and farthest-approach. I'm not much of a math whiz, so I have no idea how to derive this myself; I'll probably try asking one of the sci.space newsgroups if nobody here knows offhand. Bryan


 * Just found the formulae, and put them over at elliptical orbit. They're pleasingly simple, so I think I'll update the factsheet formula to only include eccentricity alone and omit the apo/periapses. It's almost trivial to convert. Bryan

Maybe its to early to discuss this yet. But I think we should start thinking about the asteroids\meteors\comets table. - what things should be on it? - fonzy


 * Depends on the sources of information we can find. For asteroids, I suspect orbital radius, period, eccentricity, inclination, diameter and spectral class would be a good set of data to look for. Diameter information is likely to be sparse for the smaller asteroids. For comets, much the same, but with the addition of last known date of perihelion and probably without diameter - only a grand total of two or three comets have been studied closely enough to have good diameters available, AFAIK. But I'm not going to touch this until I'm done with the planets and moons, so it'll be at least two weeks and possibly more before I do any significant work on comets and asteroids. Feel free to put together a template without me, I'll make comments and stuff. :) Bryan

I dotn really know much about atseroid data. Now should the colour scheme remain as i think was originally planed so atseroids that pinky colour and light blue for comets. - fonzy

You bet! Now how are we going to deal with the fact that your max/min temps on Earth are different than what I have. Lir 05:04 Nov 13, 2002 (UTC)

Hi, some days ago I lifted the planet table from Jupiter and created the asteroid one, and didn't even know about this page! :-) Table had some different "revision" going from asteroid to asteroid, but now I think it's quite stable. I read above some debate about the discoverer, but it should stay there. At18 1 Feb 2003


 * Hi! I haven't done much with this wikiproject in recent months, real life sucked away much of my free time, but I'd always intended to one day come up with a table for minor planets. Your approach looks quite good, thanks for kickstarting it. My only suggestion offhand would be to move the "discoverer" row up to the top of the table, since that's where it is in the planetary tables. I'll do that myself, if there's no objection, next time I've got a chunk of free time. Bryan


 * No problem, change it as you wish. I'll look at some more asteroid and some stars too At18

Hi, Any suggestion for the table in List of meteor showers? -- looxix 23:34 Apr 3, 2003 (UTC)

At18, nice table for galaxies but probably too wide. -- looxix 19:21 Apr 21, 2003 (UTC)


 * Seems to be wide mainly from the text fields - keep them short and it should be OK. At18 21:56 Apr 21, 2003 (UTC)

Galaxies
The table for galaxies should specify what mass is being measured: mass of stars from visible light (with a mass-to-light ratio assumed or calculated), mass of atomic hydrogen (radio observations), or dynamical mass (from doppler shifts of stars on opposite sides of the galaxy).

I would also like to see what type of galaxy it is; i.e., Hubble or deVaucouleurs type, spiral, elliptical, and all the subcategories.

Zandperl 19:22, 20 Oct 2003 (UTC)

The category Galaxies contains articles and subcategories entitled both 'Galaxy (thing)' and 'Galactic (thing)'. Although I can't spot any duplication, a standard naming convention might assist... Ian Cairns 17:48, 9 Mar 2005 (UTC)