Talk:List of trans-Neptunian objects

Untitled

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

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 (talk • contribs) 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?

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

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

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)

Diameter of the moons

Some of the diameters of the moons may be accidental be of the primary instead. I fixed the value for "26308 I", the other values might still be wrong. Tony Mach (talk) 12:13, 27 January 2016 (UTC)

Thx for noticing. As the figures displayed in this table are plausible and there is no indication for a systematic error, I removed your {{Contradict}}ion hatnote Rfassbind – talk 12:26, 21 September 2016 (UTC)

List of trans-Neptunian objects – unmaintainable?

I have concerns whether this TNO list will be maintainable. As of August 2016, there are only 332 numbered TNOs, but it seems this number could significantly change in the near future. Just look at the newly numbered TNOs (in #-range 470,000–473,000):

• (470027)
• (470083)
• (470308)
• (470309)
• (470316)
• (470443)
• (470523)
• (470593)
• (470596)
• (470599)
• (471137)
• (471143)
• (471150)
• (471151)
• (471152)
• (471155)
• (471165)
• (471172)
• (471196)
• (471210)
• (471272)
• (471288)
• (471318)
• (471325)
• (471921)
• (471954)
• (472231)
• (472232)
• (472235)
• (472262)
• (472271)

Proposals

1. Remove template {{TNO list}}, which is used as a row-template in this table. It is a burden, completely undocumented and not used elsewhere. This limits the number of potential editors.
2. Orbital parameters (a, q, Q, e, i) and magnitude (H) are already outdated and should no longer be displayed. A link to the corresponding MPC/JPL websites, and/or to the "list of minor planets" (which has a MPC-link) should be suffice.
3. What about the columns "Diameter" and "Notes", that are already sparsely populated and its source is not given? I presume the data is sourced from the johnstonsarchive, which includes info for column "dynamical class" (which is otherwise hard to find). These columns do not seem to be maintained either.
4. The list should be split-up in numbered and unnumbered TNOs.
5. There are ways to generate a list automatically (based on MPC/JPL/johnstonsarchive data files).

In any case, the structure (data fields) of this table should be reconsidered and simplified. I think it needs to change now, not in 1 or 2 years. If no one replies to this proposal, then I might be tempted to implement such version myself. Rfassbind – talk 17:23, 21 September 2016 (UTC)

"1930 BD" for Pluto

I get that this is included for correct sorting, but surely we should not be so prominently putting up a made-up designation? Double sharp (talk) 08:09, 13 July 2017 (UTC)

Absolutely, 1930 BD is not a valid designation (MPC) and should therefore be removed. If the template {{TNO list}} has a sorting problem, then it needs to be fixed differently. Actually I don't like this template, as described in my post from 2016 (above). I just have updated 47171 Lempo, but the template links to Lempo instead... Rfassbind – talk 11:37, 11 October 2017 (UTC)

Split article

As suggested in November 2017, the article should be split due to its size. I propose to break it up into two lists:

• List of trans-Neptunian objects (numbered objects only)
• List of unnumbered trans-Neptunian objects

as done with the MP-catalog. Rfassbind – talk 12:14, 9 December 2017 (UTC)

Managing the tables and selecting data

Yes, these lists are already too long, but I do not think a split between numbered and unnumbered objects makes sense. For one thing, this is a distinction which readers are very unlikely to care about or take into account when looking for information about TNOs. Also, this hasn't solved the issue anyway.

For this page to be useful, it needs to restrict itself to selected TNOs. The number of entries should not come anywhere close to a 4-digit number. Selecting information is an essential function of an encyclopedia - copying extensive databases isn't. Those few readers who need access to a complete list of TNOs can follow the appropriate links to the page's sources.

The current incarnation of this page actually seems a large step back to me, being on one hand overloaded with data, while on the other omitting essential information. I propose the following:

1. Focus on a few hundred selected TNOs, prioritizing named objects, likely dwarf planet candidates, objects with well-known physical characteristics (especially mass and diameter), objects with unusual orbits or orbital elements, objects of special interest for various reasons (for example, early discovery or disputed classification), and objects that are typical for a class of objects (specific resonances, collisional families etc.)

2. Merge the lists for numbered and unnumbered objects. That distinction only serves to make information harder to access and compare.

3. Leave out superfluous information, as well as information that is not interesting to compare. In the current list, the year of discovery is superfluous if the provisional designation is given (which is already the case by all unnamed objects, and it should be added to named objects as well). Places of discovery and names of the discoverers do not belong into such a table, because people are not going to compare them - they might be interested in the circumstances of a specific object's discovery, but those will be just one click away.

4. Add (back) information which enables readers to understand the role an object plays in the solar system, and which allows for interesting comparisons and sortability: Orbital period, semi-major axis, perihelion, aphelion, eccentricity and inclination are essential orbital elements - without these, this table seems to serve almost no purpose anymore. Also essential are absolute magnitude, estimations of diameter and mass (if available), and the names of moons.

Error discovered. I have not been here for a while, so I hope I am not vandalizing. However I found a suspected error,474640 Alicanto, date discovered is listed as 2004, however all the nearby entries are 2014. and it is by date discovered. So logically speaking it is 2014. I would edit it. But I have learned that even a minor edit would require approval. So would a mod get on that. — Preceding unsigned comment added by 76.210.254.132 (talk) 18:33, 13 December 2023 (UTC)

5. Explain data that is not easy to understand. The current list, for example, uses color index abbreviations without any explanation of even the most general kind (especially that they refer to the object's color index!). Other such data that could be useful, but need some explanation, are argument of perihelion, longitude of the ascending node, mean anomaly, mean motion and estimated albedo.

Keep in mind that the point of a Wikipedia page is not to provide a complete reference for experts, but to present an accessible, understandable and insightful overview for interested laymen! — Preceding unsigned comment added by 85.179.110.144 (talk) 19:16, 9 December 2017 (UTC)

It seems to me you are interested in a List of notable trans-Neptunian objects, with a "selected few hundred" bodies, based on a set of criteria. As per WP:LISTCRITERIA, these selection criteria should be unambiguous, objective, and supported by reliable sources. Can you provide such criteria to determine which TNOs should be part of such list and which not? Best, Rfassbind – talk 00:01, 12 December 2017 (UTC)

The very next paragraph also notes: "As Wikipedia is an encyclopedia and is not a directory, repository of links, or means of promotion, and should not contain indiscriminate lists, only certain types of list should be exhaustive", and "common sense is required in establishing criteria for a list". So, I appeal to your common sense here!

As for inclusion criteria that are not enitirely unambiguous (like having an official name), I find the following quote from your linked page relevant: "In cases where the membership criteria are subjective[...]it is especially important that inclusion be based on reliable sources given with inline citations for each item." (Without doubt, the MPC and JPL sources you already use qualify as reliable.) So, Wikipedia _does_ acknowledge that membership criteria for lists can be subjective by necessity (which is again just common sense, resulting from the basic function of an encyclopedia).

As for the notability of objects, there is de facto already a selection process which governs if a TNO has its own Wikipedia entry. If you just follow that lead, you will probably get very close to a good selection. Skimming over the current tables, I get the impression that removing all objects without their own entry would get that list down to a manageable number, while leaving out very few objects, if any, of specific interest (and if so, they can be re-added, preferrably while also creating an entry for them).

If it seems especially important to you to have a list of all TNOs in one place, in the vein of the lists of numbered and unnumbered minor planets already existing on Wikipedia (which I feel makes the maintenance of an additional exhaustive TNO list unnecessary, but your mileage may vary), you should split this page into a list of selected TNOs which provides all important information (especially orbital characteristics), and an exhaustive list on another page which serves the same, more basic function as the MPC lists (being exhaustive and providing links). That list then can be as long as needed, just like the MPC list, but I wouldn't expect it to get too many hits, while the shorter, but more information-dense list would be helpful again. — Preceding unsigned comment added by 77.180.135.222 (talk) 01:17, 12 December 2017 (UTC)

Quaoar, Sedna and Orcus as recognized dwarf planets?

Guys the edit I'm going to make is a bit controversial but in the article. It said Quaoar, Sedna and Orcus are recognized dwarf planets? The IAU only recognized 5 dwarf planets but why is it suddenly 8? The IAU haven't announced it yet. My planet is Homlos (talk) 01:02, 5 October 2025 (UTC)

@My planet is Homlos: Wikipedia is not necessarily following IAU in what objects are considered dwarf planets. We have arrived at a working policy here. The short version of that is that anything in Wikipedia:Featured topics/Dwarf planets is considered a dwarf planet as far as Wikipedia is concerned. The long version is more complicated, see the guideline as described at Wikipedia:Naming conventions (astronomical objects)#Dwarf planets. Renerpho (talk) 02:00, 5 October 2025 (UTC)

Well, It said "all of them being officially recognized as dwarf planets by the IAU" But that's not true. My planet is Homlos (talk) 10:51, 6 October 2025 (UTC)

@My planet is Homlos: Please don't take that quote out of context. The article says: The largest known trans-Neptunian objects are Pluto and Eris, followed by Haumea, Makemake, Gonggong, Quaoar, Sedna, and Orcus, all of them being officially recognized as dwarf planets by the IAU except for Gonggong, Sedna, and Orcus

In addition, there's this from List of possible dwarf planets: The International Astronomical Union (IAU) defines dwarf planets as being in hydrostatic equilibrium, and notes six bodies in particular: Ceres in the inner Solar System and five in the trans-Neptunian region: Pluto, Eris, Haumea, Makemake, and Quaoar. [...] Smaller trans-Neptunian objects have been called dwarf planets if they appear to be solid bodies, which is a prerequisite for hydrostatic equilibrium: planetologists generally include at least Gonggong, Orcus, and Sedna. Quaoar was labelled as a dwarf planet in a 2022–2023 annual report [by the IAU].

Renerpho (talk) 13:12, 6 October 2025 (UTC)

Oh sorry I didn't read the last part I thought it's only"except for Gonggong". Really sorry My planet is Homlos (talk) 13:31, 6 October 2025 (UTC)

Source for diameters

@My planet is Homlos: Please note that our list uses Johnston's Archive as the source for the diameters, and will probably revert back to it with the next update of the list. Please don't change the diameters to something used elsewhere without actually adding a reference for that directly in the list. There are cases where using a different reference is justified (Johnston's Archive isn't perfect), but Sedna is probably not among them.

You seem to struggle with adding citations (indicated by these edits). While Orcus doesn't actually need a reference in the lede, because we are using the same reference for it than for most of the objects, a change to Sedna definitely would need a citation. The next time you need technical help with this, just ask. Renerpho (talk) 18:07, 13 October 2025 (UTC)

Oh sorry I thought Nrco0e thinks using Johnston's Archive is not a good idea, I think I might have misread it. My planet is Homlos (talk) 22:49, 13 October 2025 (UTC)

Maybe they do... @Nrco0e? Renerpho (talk) 23:19, 13 October 2025 (UTC)

Eh, Johnston's Archive tends to be outdated. For example, it hasn't updated its orbits and diameters for Huya and Haumea. It would be nice to use up-to-date sources for each object, but finding and citing all of these individually rather than from a unified database like Johnston's becomes extremely tedious (not to mention that people can easily change numbers, lie about sources, and fail source verification). I wouldn't be surprised if this is the reason why we chose to use Johnston's for this list. Nrco0e (talk • contribs) 23:52, 13 October 2025 (UTC)

Yes, I believe it is mostly so that the table can be updated a bit more easily. I wouldn't be opposed to having a different source for the diameter of individual objects, but there should be a citation in the table, directly with the number. Renerpho (talk) 00:36, 14 October 2025 (UTC)

Mad respect for your recent edit, This must have taken a long time. Even though some of their diameters are extremely off (1995 SM "701km and in its article not even 200 km) I am still ok to Johnston's Archive My planet is Homlos (talk) 08:38, 14 October 2025 (UTC)

@My planet is Homlos: The diameter of 186.7±1.8 km for 1995 SM55 (corresponding to an extremely high albedo of 0.80) comes from a stellar occultation. That result was only published in August 2025, after Johnston's Archive's latest update from June. Before that change, the article listed Johnston's number as one of several possibilities. Johnston generally assumes an albedo of 0.44 for Haumea family members of unknown size, like this one. I don't know why his table lists an albedo of 0.04, but this is clearly in error.

This is one of those cases where a change to the table would be completely fine. Feel free to change cases like this, but make sure to add a reference directly at the diameter in the table, so it is clear that this number comes from somewhere else. When you do, make sure to change the albedo accordingly, those numbers belong together. Renerpho (talk) 13:07, 14 October 2025 (UTC)

This list use to be somewhat useful for the larger TNOs, diameters were based on scientific sources. Recently someone updated with disproven and nonsensical values that has made this list useless as a resource. ~2025-31181-94 (talk) 14:23, 4 November 2025 (UTC)

@~2025-31181-94: That someone would have been me. If you could point to a concrete example where the data is "disproven and nonsensical", that may help us fix the problem, and to make the list as useful as possible while adhering to Wikipedia's standards regarding verifiability. Renerpho (talk) 15:17, 4 November 2025 (UTC)

Rd's

184314 Mbabamwanawaresa redirects to the MP list, but 472235 Zhulong redirects here. Does it matter? (I haven't checked where variants of those names go.) — kwami (talk) 21:20, 24 January 2026 (UTC)

@Kwamikagami: There was a deletion discussion at Wikipedia:Articles for deletion/184314 Mbabamwanawaresa in October 2025, resulting in a redirect to List of trans-Neptunian objects (and explicitly not to List of minor planets: 184001–185000). However, about a month later, User:MrPersonHumanGuy changed the redirect target to List of minor planets: 184001–185000 (see Special:Diff/1321922122), claiming it to be the "more helpful target" in their edit summary. I am not watching the redirect page, so I didn't notice the change.

I believe that all TNOs should be redirected to the List of trans-Neptunian objects; and that possibility was explicitly added to the WP:DWMP guideline in October 2025, following the deletion discussion for 184314 Mbabamwanawaresa (Special:Diff/1315464719). Given that there was a recent consensus that contradicts MrPersonHumanGuy's move, I would have appreciated a discussion if they disagree with the change to the guideline, rather than a unilateral change. I can only suspect that MrPersonHumanGuy was unaware of the previous discussion. Renerpho (talk) 23:16, 24 January 2026 (UTC)

Probably. I'll rd the various names of both to here. — kwami (talk) 23:18, 24 January 2026 (UTC)

I was about to revert the change to 184314 Mbabamwanawaresa myself, but if you're already at it, go ahead. Renerpho (talk) 23:21, 24 January 2026 (UTC)

By "more helpful", I mean that Mbabamwanawaresa's MP entry can be seen right from the get-go at my proposed alternative target, whereas with the current community-preferred target, a reader has to scroll down quite far to find Mbabamwanawaresa's entry, and they may miss it too easily if they scroll too fast. I tried adding an anchor, but that caused the entry to be obscured behind the top row, so it didn't seem "helpful" to me either. – MrPersonHumanGuy (talk) 00:06, 25 January 2026 (UTC)

Yeah, that is a problem.

I linked to the ID of the object 2 rows above, and that seems to work well. — kwami (talk) 00:35, 25 January 2026 (UTC)

I tested both and the ranges of numbers visible to me without scrolling are 275809–315530 for Mbabamwanawaresa and 495613–500856 for Zhurong.

In case you're wondering, I use Vector 2010 on a maximized browser window on a 1920x1080p desktop. – MrPersonHumanGuy (talk) 01:32, 25 January 2026 (UTC)

I can confirm both of those ranges (I use the same settings as MrPersonHumanGuy). I'm not sure why the anchors are working properly at List_of_minor_planets:_184001–185000#314, while List_of_trans-Neptunian_objects#184314 leads to the entry for 208996 Achlys, but the redirect to List of trans-Neptunian objects#183964 leads to the entry for (275809) 2001 QY297 in the completely wrong part of the table. A bug? Renerpho (talk) 06:01, 25 January 2026 (UTC)

I made the links to the 2nd object above the targets so that they would be visible to the reader, per MrPersonHumanGuy's comment above. — kwami (talk) 06:27, 25 January 2026 (UTC)

@Kwamikagami: I understand, but that doesn't seem to work, since the link points to the wrong section of the table (about 10 rows too far down). Renerpho (talk) 07:54, 25 January 2026 (UTC)

Ah, I suppose it depends on which column the table is sorted by. I don't know why it would sort differently by default for different people. — kwami (talk) 08:15, 25 January 2026 (UTC)

@Kwamikagami: I don't think it's about sorting. I think the table is sorted the same way for everyone. I'm not sure what the issue is about, since the pointers work just fine for the Lists of minor planets. One difference between those, and the list of TNOs, is the use of a sticky header in the list of TNOs. I just tested if that makes a difference; and indeed, it does, but it doesn't solve the problem. It does however cause the redirect to land at a different row (different by a couple of rows), compared to the version with the sticky header. Renerpho (talk) 16:51, 26 January 2026 (UTC)

It sounds like for you the link does not land on the row with the anchor, so there might be a bug either in our software or your browser, or maybe it's a matter of CPU allocation. For me, it always lands on the target row, it's just that that row is masked by the sticky header. — kwami (talk) 00:29, 27 January 2026 (UTC)

Yes, and it lands on the exact same wrong row as it does for MrPersonHumanGuy. Renerpho (talk) 05:36, 27 January 2026 (UTC)