Talk:Natural satellite

Why are the asteroids included in a list of moons? They don't revolve around planets, if I recall, but around the Sun.

- montrealais

I put them there merely for purpose of comparison. They're in the same general size class as moons, and so comparing them helps get a feel for them both. Bryan

If we are going to include some of the larger asteroides in this artcle, should we also include the larger KBOs jeff8765

Sounds reasonable to me. Perhaps to save space, though, they should be combined into the asteroid column, which can then be renamed "minor planets" or somesuch and maybe moved to the right side of the table (rather than remaining between Mars and Jupiter)? I can do the work, if that sounds good to everyone. Bryan 02:45, 4 Mar 2004 (UTC)

Sounds good to me --- I think that putting the "minor planets" column off to the right partially answers Montrealais' objection & accounts for KBOs nicely. Btw, I like having the minor planets in there for comparison. -- hike395 05:38, 4 Mar 2004 (UTC)

All prepped and ready to go, but I'm just about to turn in for the night so I'm not going to add any KBOs myself just yet. I'll get to it tomorrow if nobody beats me to it. Bryan 06:17, 4 Mar 2004 (UTC)

Oh, this raises an interesting issue. Pluto itself has a diameter of only 2320 km, and Mercury 4879.4 km; both of these diameters fit into the range covered by the table. How about changing "minor planets" to "other objects" and including these two planets in with them as well? Bryan 06:27, 4 Mar 2004 (UTC)

While fewer people are considering Pluto a planet these days, Mercury's another story. I guess we'll have to wait for the IAU. - Jeandré, 2004-03-17t11:30z

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I've changed the 750-1 000 row, to 900-1 000 to cut it off at 2002 TX300. Another option would be to include "(too many to list)" below 20000 Varuna (and then order everything by size!), and change the row name to 500-1 000, since it's kind of ill-proportioned at the moment. - Jeandré, 2004-03-17t11:30z

Another alternative (which is more balanced) is to give upon listing "other objects" less than 1000km, because more and more TNOs will be discovered in that size range... Also, I think Ceres & Varuna are both >1000km? (I've seen a 1003 km estimate for Ceres). -- hike395 15:11, 17 Mar 2004 (UTC)

I agree with the 1000km cut off. Some (good?) sources: Varuna 900km (+125/-145) (http://www.ifa.hawaii.edu/faculty/jewitt/varuna.html). Ceres 950 × 920 (http://www.johnstonsarchive.net/astro/wrjs103sp.html), 930 and 970 (http://www.hohmanntransfer.com/cgi-bin/get.cgi?num=1). - Jeandré, 2004-03-17t17:12z

Agree that Ceres is <1000km (took it out already) I did some research a while ago on Varuna's diameter. The latest paper from France & Spain[1] (http://despa.obspm.fr/~tno/lellouch2002_varuna.pdf) gives a thermal estimate above 1000km. Dr. Jewitt's web page does not reflect the latest work, because it was published in 2001. In fact, the Lellouch paper cites the Jewitt paper. I'd like to stick with the latest results. --- hike395 18:29, 17 Mar 2004 (UTC)

More, from Lellouch's paper (JAE01 being the 2001 Jewitt paper) ---

We find D = 1060+180−220 km. Although our central flux value, when rescaled to 850 m, is 25–30% lower than JAE01's, our inferred nominal value is slightly higher than theirs; this is due to different assumptions on the millimeter emissivity, the distribution of temperature, and the fact that JAE01 adopted the Rayleigh-Jeans approximation (which is relatively inaccurate at 0.8 mm – about 20% error for T = 45 K). With our model, we would infer a 1220+175 −200 km diameter from JAE01's measurements. The two determinations nonetheless overlap within error bars.

So, shall we keep Varuna > 1000km? -- hike395

IANAA, but that looks good to me. I've found another link to Lellouch's 1060⁺¹⁸⁰_-220 data (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2002A%26A...391.1133L&db_key=AST&high=3d6ea7529519790) on the Johnston's Archive (http://www.johnstonsarchive.net/astro/tnodiam.html) site which I've found useful. - Jeandré, 2004-03-17t22:01z

I really think Ceres should be on that table, at the very least; it's the largest asteroid and people will be curious about how the asteroids measure up. How about modifying that (too many to list) note to (and many others), and insert a couple of notable asteroids into the sub-1000km cells? Bryan 00:43, 18 Mar 2004 (UTC)

That's a good compromise. -- hike395

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I was curious as to why Saturn's newest moons have been listed under unknown, I've been able to find figures that generally agree on Scott Sheppard's page (http://www.ifa.hawaii.edu/~sheppard/satellites/satsatdata.html) and a JPL page (http://ssd.jpl.nasa.gov/sat_props.html). Hope those are helpful, this is a very informative entry. - patteroast

Thanks! I incorporated the diameters from Scott Sheppard. -- hike395

I think there's some similar info for Uranus and Neptune's smaller moons on Scott Sheppard's site, also. It'd be nice to get rid of that unknown section. :) - patteroast

Done -- hike395

Method?

What is the ordering of moons and others in each box? It is not alphabetical, order of discovery or distance from sun. Is it random? Or are there just mistakes in the ordering? Rmhermen 04:58, Apr 3, 2004 (UTC)

It could be that several different editors each thought the ordering was based on a different characteristic, and so the combination of their additions has resulted in this confusion. :) How about we arrange the names in order of size, since the table is already ordered that way on a large scale? For the little tiny moons that are all about the same size (or as near as we can tell, anyway) we could resort to some other ordering. Bryan 19:33, 3 Apr 2004 (UTC)

Sounds good. We should mention that somewhere. Bound to more more moons discovered -but probably only small ones. Of course, the box with Sedna, Quaoar, etc. will be anyones guess as to size order. Rmhermen 20:00, Apr 3, 2004 (UTC)

I suppose a good method of arranging the smallest moons when they all have the same size is to go by discovery order. I'm cringing at the thought of seeing all those S/2003 Jx's every which way, though... patteroast

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What source is being used for the moons' sizes? I was trying to do a little editting to put some of the ones in order when I noticed several weren't in the right box in the first place. I know it depends greatly on the source, but as an example, the only source cited on the page (Scott Sheppard's Site (http://www.ifa.hawaii.edu/~sheppard/satellites)) and JPL's site (http://ssd.jpl.nasa.gov/sat_props.html) gives Himalia's diameter as well over 100 km, in fact it gives a figure larger than Amalthea! I'd go on an edit spree, but I want to know if there's a different source being used - want to keep it self-consistent. If not, I'll be happy to do some re-arranging. Also, I think I'll add JPL's page as an addition source in the article now. --Patteroast 22:01, 20 Apr 2004 (UTC)

Looks like User:Bryan Derksen started the page about 2 years ago by moving the table from some other page. I am not sure we can track down a single source used for sizes. Probably best to find the most reliable source we can and make whatever changes are necessary. Rmhermen 13:53, Apr 21, 2004 (UTC)

I recall creating the table in the first place, but darned if I can remember what the specific source of the information was from. I believe (not certain, but fairly confident) that I took the information from existing Wikipedia pages. Some of that information would have been placed there by others, so I can't tell where it came from, but I recall that at the time I was expanding a lot of planet and moon pages with information gleaned from nineplanets.org (http://www.nineplanets.org/). You might concievably find an earlier version of the table in the history of moon, since it was about that time when I split it into separate articles for Earth's moon and moons in general. Bryan 15:18, 21 Apr 2004 (UTC)

Well, if nobody minds, I'm going to update them. I'm using JPL's SSD information except where it's not available (a few of the most recent moons), in which case I'm using Scott Sheppard's data. --Patteroast 21:50, 21 Apr 2004 (UTC)

By all means. Just make sure to check the articles of the moons that need changing to avoid introducing inconsistencies that will confuse future editors all over again. :) Bryan 23:57, 21 Apr 2004 (UTC)

Okay, I went to try to do that, and.. I came up onto a few issues. 1) Some pages list the radius and some pages list the diameter. Not an unsurmountable problem, but it does cause some confusion. 2) With so many different references listing sometimes wildly different figures, which are to be trusted? For my own personal study, I've been using figures from JPL's Solar System Dynamics pages for the larger and mid-sized moons, and Scott Sheppard's page for best estimates of some other newly discovered moons. It just seems strange to change it to what I think is right without say. Perhaps there should be an agreed upon reference? 3) Finally, for irregular bodies, I've seen that the longest axis seems to be the favorite to be listed as the diameter or radius, instead of an average of all axes. I think this method's preferable, as it more accurately shows the volume of the object. Anyway, I could just start changing things, but I figured mentioning it somewhere would be a good bet, beforehand. Thoughts? :) --Patteroast 22:43, 24 May 2004 (UTC)

If you are going to be working on them, standardizing them all on either radius or diameter would be great. I don't care which but could we get them all to the same standard. Rmhermen 14:48, May 25, 2004 (UTC)

Right. I've started work on a new standard, using the mean diameter, using figures from JPL's SSD page where possible, and any info not available there being provided from Scott Sheppard's page. --Patteroast 15:23, 22 Jun 2004 (UTC)

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I'd like to bring up a question.. would it be appropriate to create pages for unnamed moons? We have virtually the same amount of information about many of them as some recently discovered named moons.. and there are pages for un-numbered asteroids, which is sort of the same thing. I realize many would be named, but that may take years.. especially for objects like S/2000 J11 and S/1986 U10 which have been passed over for naming several times. I'd take up the task of creating the pages, and when they're named to change links and move them. How's that sound? --Patteroast 15:23, 22 Jun 2004 (UTC)

I'd say go for it, no reason not to. -- Curps 16:29, 22 Jun 2004 (UTC)

Seconded. That's what the "move this page" function is for. :) Bryan 00:29, 23 Jun 2004 (UTC)

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I moved Charon to be a moon of Pluto. I know all about the controversy over whether or not Pluto is a planet, but I think it is still usually accepted as one. In addition, given that Charon is its moon (whether or not it is a planet) Charon should still be considered a moon. If the consensus is that this is wrong and that Charon really should be under "Other Objects" then it should be footnoted to explain why this is the case for the reader. Mfriedma 15:45, 25 Dec 2004 (UTC)

Jupiter's less-than-10km-diameter satellites

Back when I first implemented this table layout there were a whole lot fewer of these, but now that one cell is stretching the table hugely. Anyone object if I collapse it down to "too many to list, see Jupiter's natural satellites?" The downside is that there would no longer be a link for every moon in the solar system here, but I'm not so greatly worried about that now that there are categories and navigation footers and whatnot to keep track of them with. Bryan 00:58, 26 Jan 2005 (UTC)

Sounds fine to me. -- Patteroast 02:11, 26 Jan 2005 (UTC)

Ok with me. -- hike395

Make that "at least XX, see Jupiter's natural satellites" and I'll be happy.

Urhixidur 04:36, 2005 Jan 26 (UTC)