Talk:List of Solar System objects by mass

message: I started this page with the expectation that it would be relatively easy to find masses for the planets and their moons, and a few of the major asteroids and planetoids and so forth. The masses of the planets are fairly well known, but I had a ridiculously difficult time trying to find good, reliable sources for the masses of moons (especially those of Uranus and Neptune). I tried NASA's Solar System Exploration page, which appears to give pretty good values for most moons. As I started updating the masses to match those given by SSE, however, I noticed that the masses of many moons (31, in fact) are given as 8×1017 kg. It appears that SSE is using this number to indicate an uncertain or unknown mass rather than simply saying "unknown," which makes me question the accuracy of the other numbers. Until I can resolve that, I'm going to avoid using SSE values, so if anyone knows of other reliable sources, please post them here or update the page yourself. --Bkell 22:42, 19 Mar 2004 (UTC)
replies: text: I think those moons are listed at that number because they're all rounded to around the same size. Most of the newly discovered moons have very little known about them. I've seen orbit sizes changed by more than ten million kilometers in months. At this time, we only have very rough estimated of thir size, and the masses are probably inferred from estimating the mass of a sphere of that size with a guessed density. Anyway, I admire the effort put into this page, I've always wanted to try something like this myself, but I'd never been able to find enough reliable info on objects under the size of Ceres. --Patteroast 00:00, 6 Apr 2004 (UTC)
thread_title: Trustworthy sources for data

message: I originally started this page as a table, and then moved to an ordered list, since it seemed to me that it would be nice to be able to quickly ascertain a given object's rank in the solar system. Curps changed it back to a table today, which has its benefits, among them the fact that the masses are nicely aligned. The problem is that now the ranks are gone.
I realize that assigning rankings to some of the objects lower in the list is somewhat misleading, since it's very likely that there are larger objects in the solar system that just aren't in the list because their masses aren't well known. But I think it would be nice to have rankings for at least the first few objects; after all, I think we're fairly certain that Earth is the sixth most massive object in the solar system, so it would be nice for it to be labeled "6".
Perhaps we can just add another column down the left side of the table for the rank. Any opinions out there? —Bkell 03:50, 14 Apr 2004 (UTC)
thread_title: Formatting

message: While looking for masses for 31 Euphrosyne and 65 Cybele, I found some interesting sources which I will not be able to wikipediate all the useful content from today. These masses are given in terms of Solar masses, not in kilograms, and so will need to be converted.
*Masses of the largest asteroids
*Determination of mass of Jupiter and that of some minor planets from observations of minor planets moving in 2:1 commensurability with Jupiter
--Arkuat 23:33, 2005 Jun 23 (UTC)
:My impression was this page is not supposed to list all bodies in the solar system, rather those with mass greater than 1 billion metric tons (1015 kg). If you think that lighter bodies should be added, start with Jupiter's natural satellites, Saturn's natural satellites, Uranus's natural satellites and Neptune's natural satellites. Smartech 8 July 2005 14:42 (UTC)
1015 kg sounds like a good cutoff to me, in that we really shouldn't add anything less massive than that until we're all confident that the list is complete for more massive objects (which seems unlikely given the recent discovery of objects such as Sedna).  And by the way, oughtn't this article be titled "List of Solar system objects by mass"?  It's only a case quibble, so I hesitate to do a "Move this page" without discussing it on the talk page first. --Eric Forste 9 July 2005 08:19 (UTC)
: Yes, well technically the article should be named "List of known Solar system objects", because obviosly, we dont know all of them and most likely never will, or at least it looks like we never will now. But the point is, that applies to all articles more or less, because things are not fixed. Smartech 00:49, 11 July 2005 (UTC)
replies: text: The capitalization is fine, I had already gotten it the first time ;) If you read about the (assumed) Zipf distribution of bodies in the solar system, it is clear that the smaller the dimensions, the lower the percentage of total bodies that we know of. Smartech 05:03, 11 July 2005 (UTC)
replies: text: Why should "solar" be capitalized? It isn't capitalized in the solar system article. Yes, we're discussing a particular planetary system, but we aren't saying "the Sol system". Words such as "solar" and "lunar" usually aren't capitalized. —Bkell 20:59, 9 August 2005 (UTC)
thread_title: Other sources, cutoff size for mass, and capitalization of "Solar"

message: The French version of this article has added several large TNOs that may not have independent articles in the English wikipedia yet, and in any case probably don't have masses listed yet. Personally, I'm more interested in the missing large asteroids, but I may get around to working on these TNOs someday.  In the meantime, I thought I'd mention it here in case someone else would like to do that. --Eric Forste (Talk) 02:14, 13 August 2005 (UTC)
thread_title:  Interwiki .fr 

message: I have change the listed mass of Icarus from 1.0 to 2.9, as this is the mass listed on the "Icarus" page both in Wikipedia and on "http://www.answers.com/topic/1566-Icarus". I have never changed any-thing in Wikipedia before and is therefore not accustomed to the procedure, so I would like to apologize beforehand if this correction has been unwarranted...
allan N
:No worries, you did the right thing.  Thanks for noticing and correcting the problem! DenisMoskowitz 19:26, 10 November 2005 (UTC)
thread_title: Minor correction

message: Is there a reason the sun is listed in Spanish instead of English? (sol) | Phaldo 16:56, 1 January 2006 (UTC)
replies: text: See the Sol article. Ardric47 02:06, 27 February 2006 (UTC)
thread_title:  Naming of sun 

message: I would suggest cutting off all trans-Neptunian objects at the 1020 kg point, barring something really notable. The suggested cutoff corresponds to a diameter of 457 km (assuming the usual density guess of 2.0 g/cm<sum>3</sup>). While the population of TNOs is poorly sampled at all size ranges, this cutoff at least corresponds to about the size at which icy satellites compress to a spheroid from self-gravity. Deuar 18:42, 7 February 2006 (UTC)
replies: text: The simply truth is that we have very little idea as to the diameter (within a factor of about 2) of your average TNO, and unless a TNO is a binary object we know nothing about its density.  If we do not have an accurate diameter and only a "wiki-guessed density", the resulting mass will be a wild guess.  We still do not know the correct size of 2060 Chiron and for many years Pluto was assumed to be several times more massive than the Earth.  Most of the masses on this list are best guesses (with hopefully a reviewed paper backing them up.) -- Kheider (talk) 12:38, 13 November 2008 (UTC)
thread_title:  cutoff mass for TNOs 

message: Added information on this "10th planet". Mass is estimated on the basis of size measurements and assuming it is very similar in composition to Pluto (ref: http://www.gps.caltech.edu/~mbrown/planetlila/index.html):
Estimated mass of 2003 UB313 = Pluto's mass * [(2003 UB313's diameter)/(Pluto's diameter)]3 = 1.305*1022*(3000/2306)3 = 2.873*1022 ~ 2.9*1022 Aquirata
:Updated mass estimate on 2003 UB313 to reflect latest diameter estimate (2400 km vs 3000 km). However, I notice that the mass for Pluto in this article and the Pluto article aren't in agreement: 12.9 Yg vs 13.05 Yg. I used the 13.05 Yg value (same as the original mass estimate and the Pluto article) and rounded up 14.0 Yg, but thought I'd bring the discrepency to everybody's attention.  --Pfhreak 02:13, 13 April 2006 (UTC)
replies: text: Aren't they saying now (i.e. since the revised size measurements) that the composition of 2003 UB313 is different from that of Pluto? Ardric47 03:51, 13 April 2006 (UTC)
replies: text: I think the revised size estimate is simply based on a new measurement by the Hubble Space Telescope (http://www.gps.caltech.edu/~mbrown/planetlila/index.html#size). With that, the new estimate for how much sunlight the planet reflects was upped to 86%, but composition is still thought to be similar to that of Pluto: "Pluto, we know, has a density about midway between ice and rock, thus we think that it is made of about half and half ice and rock on the inside. The new planet, being about the same size and the same surface composition as Pluto, is probably close to the same." (http://www.gps.caltech.edu/~mbrown/planetlila/index.html, under the heading 'What is the planet made out of?' - about halfway through the article) Aquirata 23:59, 16 April 2006 (UTC)

text: Using Pluto's mass as 13.05 Yg, I get 14.7 Yg. Hence, i'm rounding up to 15 Yg. Deuar 12:26, 22 April 2006 (UTC)
thread_title:  2003 UB313 

message: Added graph showing relative masses of selected objects today in the front matter. It is very revealing to see this in graphical form rather than trying to get a feel from the actual numbers. The list includes all objects listed from the Sun to 3 Juno. The decision to have the cut-off at Juno was made for the following reasons:
* The list includes the four major asteroids
* The graph is roughly symmetrical to the Earth as the Sun is just about as many Earth masses (330,000) as the Earth is Juno masses (200,000)
* This list divides nicely into three approximately equal sets: 1) Sun to Moon, 2) rest of the objects in Yg range, 3) Ceres to Juno 
* It's hard to include more objects without sacrificing legibility
The graph will need to be updated only in case of a major change in the main lists. It is an Excel chart, which is relatively simple to update.
Aquirata 14:00, 15 May 2006 (UTC)
replies: text: Looks great! Graphs like this shouldn't be uploaded in the JPEG format, however; please see Wikipedia:Preparing images for upload for more information. Could you make a PNG version of this graph and upload that? —Bkell 07:14, 16 May 2006 (UTC)
replies: text: I have replaced the bar graph with what is known in the business as a "dot plot", while keeping, I hope, to the spirit of Aquirata's original. Del C 17:27, 6 October 2006 (UTC)
thread_title:  Graph showing relative masses 

message: I just want to say that this article is so much more helpful than the last time I edited it. You folks make wikipedia fun for me. --arkuat (talk) 04:53, 20 May 2006 (UTC)
thread_title:  fantastic work, wikipedians! 

message: I notice that some of the objects in the "Petagram range" table are actually smaller than 1 kg. Perhaps we should rename this section or change the blurb at the top to be consistent with what we want there. Matter of fact, what do we want there? Currently there is a couple of NEOs distinguished by either being the first of their orbital class or by being radar imaged from Earth. Deuar 12:06, 15 June 2006 (UTC)
replies: text: The petagram section of this list is the only list of NEOs ranked by mass on wikipedia that I know of, so I think what we want here is a short list of the most massive known NEOs in that order. It's true that there are lots of petagram-range objects in the main asteroid belt that would be ignored, but is that so wrong? (The objects that turn out to be less than 1 kg ought to be removed, of course.) --arkuat (talk) 23:50, 18 June 2006 (UTC)

text: Yeah, I don't think we want a teragram range.  The list sections we do have are all incomplete, as it is, what with all the TNOs popping up. (This is why I want a list ranked by mass divided by delta-vee-from-Earth.)  If it weren't for the "near-Earth" aspect (I am interested in keeping track of the most massive NEOs!), I'd get rid of the petagram range list too.  --arkuat (talk) 06:18, 20 June 2006 (UTC)
thread_title:  petagram range 

message: Until recently, all the images in this list have been "real" data taken by cameras or gleaned by other methods, however since a recent edit we now have artists impressions for three bodies: , (136472) 2005 FY9, 90377 Sedna, and 50000 Quaoar. Before the number of artist's impressions grows it would be good to come to some consensus on whether we want them or not. Off the top of my head, some arguments for:
* eliminates ugly white space  
and against:
* Artist's impressions tend to be misleading -- they have rarely turned out to be close.
* Having only real data gives a good indication at a glance of how much is known about the object: good images, rough pixelly images (e.g. 1 Ceres, Himalia), not properly resolved (e.g. ), very little (all the empty image boxes). With the artist's impressions, one could be forgiven for thinking we know as much about Quaoar and Sedna as about Saturn's and Uranus's moons which are right next to them on the list.  
As for me, as you can probably guess, I much prefer having an empty space to indicate very little available data because it arouses a strong sense of curiosity about the object in me. 
However, what does everyone else think? Deuar 14:42, 23 August 2006 (UTC)
replies: text: I've gone and distinguished them from the other images by a dark grey bakground (with a note in the header). Deuar 18:03, 4 September 2006 (UTC)
thread_title:  Should we have artist's impressions? 

message: wonderful page
there are two columns for mass: yotta and kilo.  Would it be possible to have a column in plain old grams, which, after all, is the unit of weight before we start with metric prefixes or scientific notation to scale it.  This would make direct plugins of these numbers into other formulas more likely to be accurate.  Thanks.
:I believe the mass unit that is the widely used standard (at least in astronomy) is kg, rather than g.  Deuar 12:37, 25 August 2006 (UTC)
replies: text: Yes, the kilogram, not the gram, is the SI base unit of mass. The gram is actually a derived unit. —Bkell (talk) 13:01, 25 August 2006 (UTC)
thread_title: would it be possible to have a grams column ?

message: Just wondering − why do we have brackets around all the numbers in the mass column, and why do we repeat "kg" despite pointing out in the header that it's in kilograms? I'm tempted to remove this, but don't want to charge off into such a tedious business if its going to be reverted ;-) Deuar 17:57, 4 September 2006 (UTC)
replies: text: I haven't figured out the reason for all the parentheses (brackets) yet either, so go ahead and remove them.  I'd say hold off on removing the "kg"s.  My experience with teaching science to adolescents is that we must abhor naked numbers, and taking away the kg's would render all those numbers absolutely nude. Besides, it would be prejudicial against those of us who prefer daltons as a unit of mass. I'm still ruminating over your excellent remarks about the mass-vs-deltavee proposal. --arkuat (talk) 07:53, 10 December 2006 (UTC)

text: Done.  :)  I'm still thinking about your questions about how to do the m-Δv table. --arkuat (talk) 04:19, 3 July 2007 (UTC)
thread_title:  spurious brackets and units 

message: In the Solar System article, it says: "Jupiter and Saturn account for more than 90% of the system's remaining mass"
However, with the figures in this article you can calculate that Jupiter and Saturn account for less then 10% of the solar system's mass (not counting the Sun).
LEitK 03:19, 5 January 2007 (UTC)
replies: text: The figure for the whole of the solar system mass does look a bit too high. If you add up all of the figures barring the Sun, you'd get something like ~92% for Saturn & Jupiter combined - with Neptune & Uranus making up ~7% of the remaining. Richard B 03:51, 5 January 2007 (UTC)
replies: text: I removed "Solar system" from table until this discrepency is resolved. The difference is far too vast for the information to remain until verified. Serendipodous 13:28, 9 January 2007 (UTC)
thread_title:  Solar System Mass 

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thread_title: Fair use rationale for Image:Xenaandgabrielle-cropped.jpg

message: http://aa.usno.navy.mil/faq/docs/asteroid_masses.php --arkuat (talk) 22:28, 14 April 2008 (UTC)
thread_title:  another source 

message: Should we list 52 Europa by the Baer/Chesley (2008) estimate of 1.9 kg placing it below 9 Metis or should we leave it at 3.6 averaging it with the old Michalak (2001) estimate of 5.2? -- Kheider (talk) 19:59, 16 November 2008 (UTC)
thread_title: [[52 Europa]]