Talk:List of trans-Neptunian objects

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Untitled[edit]

What order is this list in? Size? Distance from the Sun? Date of discovery? It's not clear. The Singing Badger 17:36, 7 Feb 2005 (UTC)

Well, if some editors (such as The Tom) insist on splitting the number from the rest of the name, the table columns need to be correctly titled. For example, the "permanent designation" of (15760) 1992 QB1 is "(15760) 1992 QB1", not "15760". I don't see how to fix this without merging the columns back. Urhixidur 22:42, 2005 August 4 (UTC)

"(15760) 1992 QB1" cannot by definition be considered a "permanent designation" because it is ultimately in line for replacement. The number is certainly locked in for eternity, but the year/letters/number part simply cannot be justifiably placed in a permanent column. mpl- is simply a cosmetic shortener so objects that have been assigned numbers but not yet names can be placed in a table row with no duplicate or inappropriately-placed information. Also, there's no ironclad reason year/letters/number designations have to mated-in-perpetuity with permanent numbers for every single occurrence: astronomers frequently shed the leading numbering on unnamed objects for convenience's sake (even within academic contexts) just as they'll often refer to the planetoid as "Sedna" instead of "90377 Sedna" --The Tom 23:07, 4 August 2005 (UTC)

Suggestions[edit]

How do people feel about re-arranging this in terms of mass? As far as usefulness goes, I think this makes the most sense. We list the mass and perhaps also list "Pluto masses" to provide a baseline comparison. Marskell 10:08, 13 March 2006 (UTC)

Unfortunately, the masses are unknown, except for a few objects which are binaries or multiple systems (i.e. have at least one satellite), so the mass of the system could be calculated from Kepler's laws. The diameters are also unknown, except for large objects where the disk could be measured by HST or the albedo established via the thermal method and using the absolute magnitude (calculated from the apparent magnitude (the only thing really measured) with the distance known from the observed orbit and Kepler's laws). In other words, there’s not much to order this list. Even the discovery date is bit fishy because some objects had been observed earlier but not recognised as such, for instance 2003 UB313 has been actually discovered in 2005. Regards Eurocommuter 13:04, 13 March 2006 (UTC)
For the larger bodies mass is not absolutely unknown. We can provide a range. We know how big Sedna is, more or less. We know that 2003 UB313 is bigger than Pluto... Mass stikes me as eminently more useful than (putative) discovery dates (think in the "school project" sense). Perhaps not rearranging this list but making another one. I think a placeholder listing, say, the top ten bodies relative to Pluto mass makes good sense. Marskell 22:19, 13 March 2006 (UTC)
Well, I’m surprised that the mass is being put forward. Firstly, the size estimation from the albedo alone is to a factor of 3 or worse. Secondly, the densities (except the cases mentioned above) are not known, i.e. the density may easily represent another uncertainty of 2! Next; who remembers whether say (our) Moon is denser than Enceladus? As result, the comparison of the mass can easily mislead about the size. Finally, if told that the mass of a satellite is a bit more than 1% of the primary, how many people will think: 'wow, it is quite big!'? (well, it is big; it is again our Moon compared with Earth). Having said that, I’m, like you, unhappy about the discovery date. If asked, I would vote for the absolute magnitude. Given the differences in albedo it can mislead into overestimating a small-but-bright over a big-but-dim, but IMHO magnitude is more expressive than mass. The only problem with the magnitude is that it's logarithmic, so for a wide public, a TNO one magnitude dimmer or brighter than Pluto does not necessarily mean much. Regards Eurocommuter 19:23, 15 March 2006 (UTC)
What about plain old (estimated) diameter? It's equivalent to the magnitude sorting for the majority of objects, apart from a few cases where we have more accurate data (which is even better). This seems the best compromise between wide applicability and understanding by readers. It gets used in e.g. List of solar system objects by radius, List of noteworthy asteroids. Deuar 14:43, 18 March 2006 (UTC)
I agree, this table would be far more useful if it included both mass and diameter, at least for the larger named objects, if not all. As to the accuracy of the figures (referenced above), scientific information is always going to be limited to the best current observations. It's better, in my opinion, to include the best current information, with a note concerning the potential veracity of the figures, than to give no information at all. 7:52, 14 October 2013 (UTC) — Preceding unsigned comment added by 96.50.0.245 (talk)
The list is arranged by MPEC filing date because other minor planet lists are also sorted that way. A (rough) size-based list appears on trans-Neptunian object, Kuiper belt and scattered disc. The Tom 00:15, 16 March 2006 (UTC)
I would order the TNOs simply by number, as is done in List of asteroids as well. This would also put Eris to the right place. (Those TNOs without a number should be at the end of the list or even completely removed IMO) —Preceding unsigned comment added by Roentgenium111 (talkcontribs) 17:59, 19 September 2008 (UTC)
I think ordering by distance from the sun makes the most sense, and maybe use a colour code for size. At the very least, add a few more columns for AU and kg. —Preceding unsigned comment added by 99.239.198.13 (talk) 02:22, 6 March 2009 (UTC)

Why so many unnumbered?[edit]

Why are so many of the TNOs given unnumbered, although they have been discovered a long time ago and their orbits seem to be well known (according to their Wiki pages)? Or may they have a permanent number, only none of the editors knows it? (No offense!) Unfortunately I cannot search the TNOs in List of asteroids, since it is not a single page. --Roentgenium111 (talk) 21:57, 21 August 2008 (UTC)

Minor planet receive a number when it orbit is well-known. Minor Planet Center established Uncertainty parameter U. When U is 1 or 2, minor planet will receive its number and, possibly, name. You can learn if certain MP is numbered or not at JPL Small-Body Database Browser page. — Chesnok (talk) 11:26, 13 September 2008 (UTC)
Thanks for the info. However, according to your last link, Haumea should not have a number yet, because it has U-value ("quality code") 3.--Roentgenium111 (talk) 18:01, 19 September 2008 (UTC)
Maybe there is in fact other policy of TNO numbering and naming. TNO's period is very large (hundreds of years), and we cannot observe it on long arc. So, we cannot sufficiently improve quality of its orbit anon. — Chesnok (talk) 18:22, 19 September 2008 (UTC)
It's strange: some numbered TNOs have U-value 2 or 3 (Eris, Haumea), while unnumbered 2005 QU182 has U-value 1.--Roentgenium111 (talk) 21:16, 18 July 2010 (UTC)

Technical banner Added: List is all Science Gibberish, Total Lack of Courtesy for Non-Science Readers[edit]

Posting an article in all-science lingo on Wikipedia is self-centered and rude behavior.

Wikipedia is heavily read by nonscientists and that's why Wikipedia policy stipulates that all articles should include descriptions that non-scientists can understand.

Technical language may be included but editors should have the courtesy to explain their jargon so that non-scientist readers may follow the topic as much as is possible.

71.237.102.193 (talk) 20:14, 6 May 2011 (UTC)

Size in table[edit]

Added diameter data for the named objects (in the notes). -- AJ, 26 Nov 2014 — Preceding unsigned comment added by 67.130.216.230 (talk) 03:34, 27 November 2014 (UTC)

I think it makes more sense as a separate column instead of in the notes. --JorisvS (talk) 10:44, 27 November 2014 (UTC)
I tried making it a separate column, but it always merged with the "Notes" column. I couldn't find what was wrong, so put the data into the notes for now. — Preceding unsigned comment added by 67.130.216.230 (talk) 05:31, 28 November 2014 (UTC)
I took some doing, but I've tracked down the problem to Template:TNO list and made the necessary changes there and changed the table here. --JorisvS (talk) 17:21, 28 November 2014 (UTC)