# Talk:List of minor-planet groups

WikiProject Solar System (Rated List-class, Mid-importance)
This article is within the scope of WikiProject Solar System, a collaborative effort to improve the coverage of the Solar System on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
List  This article has been rated as List-Class on the project's quality scale.
Mid  This article has been rated as Mid-importance on the project's importance scale.

## asteroids

It should be made clear that when the article says the asteroids have a semi-major axis of so-and-so many AUs that this refers to the orbit of the asteroids and not the size of the actual asteroid. 134.173.94.191 09:26, 22 September 2005 (UTC)

"Minor planets (or planetoids) are objects in the solar system that orbit the Sun like planets, but which are smaller than planets and not counted among them. The most common types are asteroids, comets, and trans-Neptunian objects."

Actually this is not correct. Minor planet is the official term for an asteroid.

Jyril - 15 July, 2004

As Minor planets and asteroids are exactly the same, why not merge them into one document (asteroid) and just redirect from minor planet to asteroid???? Greetings, Jeffrey 129.125.6.1 10:59, 22 November 2006 (UTC)

Duh, see all the other discussions below. Also Asteroid should re-direct to Minor Planet (still the official term), not the other way. Tom Peters 16:32, 22 November 2006 (UTC)
Agree with merging Asteroid into Minor planet and not the other way. I will start it if noone else oppose. Öòö0 13:44, 12 May 2007 (UTC)

I don't think merging is appropriate. "Asteroid" generally refers to objects within or around the orbit of Jupiter, whereas "minor planet" is a much broader category that includes all of the little objects orbiting the Sun. Why not simply consider the Asteroid, Comet, Kuiper belt object, etc. articles to be sub-articles of the generic super-article Minor planet? Bryan Derksen 19:11, 12 May 2007 (UTC)

## asteroid group

I think this article should be renamed to "asteroid group" or something and "minor planet" to redirect to asteroids. Jyril 10:01, 6 Jul 2004 (UTC)

But this article covers all the groups of sub-planetary objects right out to the Oort cloud, not just asteroids. If not minor planet, then just what is the generic term for "not-planet Sun-orbiting object"? I think Wikipedia needs a summary article like this that covers all of them. Bryan 15:17, 6 Jul 2004 (UTC)
Indeed. Small body is good (see for example The Nine Planets). It would cover meteoroids and dust too. Jyril 15:24, 6 Jul 2004 (UTC)
Hang on, though. The definition you added to this article (whose "official definition", BTW? IAU?) says that minor planets include asteroids and trans-neptunian objects, which is exactly what this article covers anyway. I really don't see the need to rename or move anything. Bryan 15:31, 6 Jul 2004 (UTC)
Official in the sense that IAU uses the term minor planet instead of asteroid. Only thing I don't accept that comets are also included in minor planets here. Drawing the line between comets and asteroids is historical and far-fetched, but we should use the defined terms if possible and not invent own. Jyril 18:10, 6 Jul 2004 (UTC)
The only place comets are described as being minor planets is the line "If a minor body produces coma it is called a comet," in the intro paragraph. This does not say that all comets are minor planets, however, just that some minor planets are also comets. This seems to be supported by List of noteworthy asteroids#Numbered asteroids that are also comets, where there is a list of bodies that are considered both asteroids and comets. In Chiron's case in particular the key characteristic that resulted in its dual citizenship seems to have been the discovery of a coma. I'll add a clarifying note. Bryan 23:18, 6 Jul 2004 (UTC)
"Small body" is a poor name for an article, because it is ambiguous: it could refer to a human body of short stature. I'm also not yet convinced that we need to move the article. -- hike395 16:02, 6 Jul 2004 (UTC)
Doesn't the Minor Planet Center also track moons. Should those be part of the definition? Rmhermen 16:08, Jul 6, 2004 (UTC)
In a sense they are small bodies too, but that would make it too complicated. Jyril 18:10, 6 Jul 2004 (UTC)

Oh, as a side note, if the IAU doesn't consider comets (as a class) to be minor planets then Category:Comets should probably be recategorized (it's currently a subcategory of minor planets). Bryan 23:26, 6 Jul 2004 (UTC)

## Asteroid?

What is the difference between asteroids and planetoids / minor planets? -Hello World! 04:32, 2 August 2005 (UTC)

In my opinion, nothing. Here Wikipedia however asteroids seem to exclude Kuiper Belt objects and Centaurs, which is in a way justified since if one such object wanders to inner Solar system it would be called a comet (and that's what often happen). Planetoid is a somewhat outdated synonym for an asteroid. Some astronomers have proposed that the definition of planetoid should be reassigned to refer only to the largest asteroids and Kuiper belt objects. It's a pity that term asteroid became prevalent, because planetoid ("planet-like", refers to their physical properties) is more describing term than asteroid ("star-like", because they look like stars in telescopes).--Jyril 08:49, August 2, 2005 (UTC)
If "asteroids seem to exclude Kuiper Belt objects", Does it mean that comet is a kind of planetoid? Since in Chinese language, both asteroids and planetoids are translated as "小行星" (小 means small and 行星 means planets) --Hello World! 04:46, 3 August 2005 (UTC)
• Planetoid used to be a synonym for asteroid. But with the discovery of very big TNOs, the name planetoid is incresiling used by scientists, writers, media, etc to these new objects. We know that these bigger "asteroids" are different from common asteroids. So Ceres, Sedna, Quaoar, Orcus.. are planetoids. I think we should not redirect planetoid to asteroid... other wikipedias dont do it. -Pedro 23:14, 16 August 2005 (UTC)

## Separate Asteroid Family article

I'm seriously considering moving the entire part which concerns Asteroid Families to a separate article. (Including the list of families), and putting in its place a link with maybe a sentence or two. There are two reasons:

1. Quite a number of links to this article that I have encountered are just there because of the asteroid families. They are there largely because there isn't a separate article which explains the issues common to all the families.
2. A longer piece of text about the families like what I have put in today doesn't really sit well here, because this article is mostly a list of groups with only enough detail to identify what they contain.

So, i'm interested what your opinion is on this suggestion. If there is no major protest against this, I'll try to implement the move in a week or so. Deuar 22:23, 22 December 2005 (UTC)

Since there was no protest, I have carried this out. Deuar 22:06, 1 January 2006 (UTC)

## Main belt subgroups

Does anyone know where the main belt subgroups with names like Main Belt IIb asteroids come from. I've never come across them anywhere else. Is there some sub-field that they are used in? Perhaps they were introduced in a paper or two, but never caught on? (they're kind-of dull...) Does anyone have a reference for them? They look like they're never going to get an article, so if no-one stands up do defend them I would certainly suggest removing the broken wiki links, and probably deleting them outright.

While i'm on this, is there a group inwards of 2.3 AU? e.g. Main Belt O asteroids? There's a heap of asteroids around there. Why did they get the short straw? Deuar 22:37, 22 December 2005 (UTC)

I haven't heard of those groups before, but it seems that the source of the article is [1] and that page cites Clifford Cunningham's book and the MPCs. - hike395 04:19, 23 December 2005 (UTC)

## Encycolpedia or Dictionary

Hello. Wow, that's a lot of pages. But is it really encyclopedic? Or perhaps better suited to dictionary? e.g. List_of_asteroids, List_of_asteroids_(29001-30000), List_of_trans-Neptunian_objects, List_of_periodic_comets, List_of_non-periodic_comets. Is there a top-level page that discusses this project? Ewlyahoocom 13:54, 10 February 2006 (UTC)

## Resonance values need checking?

My Solar System Dynamics book says that the Hilda family is in a 3:2 resonance with Jupiter, not a 2:3 resonance as the article claims. 3:2 makes more sense since they should be completing three orbits for every two orbits of Jupiter (for comparison, Jupiter's moon Io is described as being in a 2:1 resonance with Europa and it completes two orbits for every one that Europa completes - so the inner body should have the higher number in the x:y description, surely?).

Can someone doublecheck the resonances shown here to make sure they're shown the right way round?

Thanks! Should be ok now Deuar 22:37, 23 May 2006 (UTC)

## Minor planet is not the same as planetoid ?

Minor planet is asteroid. The bodies called planetoids - the transitional bodies between planets and asteroids, which have planet-like shape and considerabl;e dimentiions, such as Sedna, Orcus, Quaoar, Xena etc. Sometimes Ceres considered planetoid.--Nixer 20:36, 5 August 2006 (UTC)

Planetoid is somewhat outdated (although more accurate) synonym for asteroid, an object officially known as minor planet. Since the discovery of large trans-Neptunian objects, Mike Brown (and perhaps others) have suggested that the name could be recoined for those almost-planet sized objects. Currently, however, the terms can be considered synonyms and no one should claim that false. Personally, I like Mike Brown's suggestion (if it's his).--JyriL talk 20:50, 5 August 2006 (UTC)

So why are there two articles on Asteroids and Minor planets? The articles claim that asteroids are a subclass of minor planets, but I do not believe that such a distinction is consistently made in old or current astronomical literature; besides, there is much overlap between the two articles. I propose to merge these, possibly under Small solar system body. Tom Peters 19:50, 25 August 2006 (UTC)

Asteroid is already 32 KB in size, and minor planet about half that. Merging them would result in an article that'd probably be large enough to warrant splitting again anyway. I don't believe there's much overlap in content, minor planet is mostly a big list of the various subgroupings by orbit and the asteroid article has only a single paragraph on that topic. Bryan 00:07, 26 August 2006 (UTC)
Minor Planet is under consideration for merging with Small solar system body in accordance with IAU recognition of that term encompassing everything that isn't a planet or dwarf planet. Asteroid might work as a sub-page to Small solar system body. As well as others, once the merge is done this should be revisted. --Exodio 02:25, 26 August 2006 (UTC)

## Small solar system bodies

If the draft definition of a planet will be adopted, the term minor planet will be no longer used. Instead, all objects orbiting a star smaller than planets are to be called small solar system bodies. That term covers objects such as asteroids, TNOs, and comets.--JyriL talk 14:21, 16 August 2006 (UTC)

Is there a difference in definition of asteroids and TNO's? I don't think so. The Centaurs for example are most likely very similar to SSSBs beyond Neptune, but by definition they are not TNO's; OTOH they are unlike the rocky major-belt asteroids. Tom Peters 15:11, 26 August 2006 (UTC)
Using planetoid would've made life so much easier... I wonder why they didn't? 132.205.93.195 21:17, 16 August 2006 (UTC)
The term seems to have been adopted happily by the IAU. I've created a stub; probably worth bulking it out quickly. Shimgray | talk | 16:43, 24 August 2006 (UTC)
Why a stub? The term used here includes asteroids and comets, exactly the same objects. Just a page move should have been enough.--JyriL talk 17:53, 24 August 2006 (UTC)
There's a total lack of evidence that the IAU intended the term SSSB to replace "minor planet". The status of the term "minor planet" isn't addressed in the IAU's resolution. IIUC "minor planet" is anything that the Minor Planet Center assigns numbers to: asteroids, centaurs, trojans, TNOs. SSSB includes most of these (per resolution) + comets and meteors.RandomCritic 08:31, 28 August 2006 (UTC)
The problem is this: If minor planets are considered as asteroids (like the IAU unofficially does), this page is redundant, but if the term "minor planet" include asteroids + comets + TNOs (like has been done here) this page is again redundant (because SSSB ~ minor planet).--JyriL talk 20:50, 28 August 2006 (UTC)
The IAU officially uses the term "minor planet" as you yourself pointed out, and according to Brian Marsden that is synonymous with "asteroid". That does include TNO's (moving specks of light without a coma that happen to orbit beyond Neptune) but excludes comets (moving specks of light with a coma that they usually develop within the orbit of Jupiter). So actual and current terminology among astronomers is that "Minor planets" are not synonymous with "SSSBs" but are synonymous with "Asteroids", so we should not merge "Minor planets" with "SSSBs" but with "Asteroids". Tom Peters 23:27, 28 August 2006 (UTC)
That's how it should be. Nobody has provided any evidence that comets are classified as minor planets. The contents of the minor planet article should be moved here, and redirect should be pointing to the asteroid article.--JyriL talk 16:22, 31 August 2006 (UTC)
There's a practical problem with this currently, in that when discussing physical characteristics, the asteroid article talks almost exclusively about rocky bodies that lie within the orbit of Jupiter. Deuar 10:50, 1 September 2006 (UTC)
This is also what the common usage of the term "asteroid" means; when most people hear the word they don't think of icy bodies in the far depths of outer space, they think of rocks caroming around the inner solar system. Keeping a separate article focused on the rocky asteroids is worthwhile on that basis alone, IMO. We should mention all these technical terminology issues of course but Wikipedia as a whole is intended for a general audience. Bryan Derksen 19:24, 12 May 2007 (UTC)

## Planetary symbols for asteroids

According to [2] there are other minor planet planetary symbols around, we should probably add it into the text (but not infobox) of the various asteroids concerned. 132.205.93.19 03:01, 25 August 2006 (UTC)

## Asteroid groups

As the majority of this article is mainly about asteroid groupings, perhaps it should be renamed to something more appropriate? Most of the remainder appears to be redundant with the asteroid article. — RJH (talk) 14:44, 17 July 2007 (UTC)

NO--121.218.164.148 04:54, 29 October 2007 (UTC)--121.218.164.148 04:54, 29 October 2007 (UTC)--121.218.164.148 04:54, 29 October 2007 (UTC)$5x690=ur mum$

## Merging stuff

There's a merging template out at the article dated Oct 2007, but none explaining why, while the previous discussions in this talk page concludes a merger to be inappropriate. Shouldn't the merge proposer talk for his (her) cause, before attaching a merge proposal? And before that, read the previous discussions at the talk page? (I agree with the result of the previous discussions - by the way - the terms are so unclear and undefined, so there is no reason for merging, on the basis that we don't know the terms' exact meaning). Said: Rursus 10:51, 10 November 2007 (UTC)

Now, this is my faulty (nonstandard, confused, subjective) opinion:
• asteroids are from between Mars and Jupiter (either being there, or have originated there), "asteroid" is a misnomer, because they're nothing like (-oid) stars (aster), but since it is outlandish, it shouldn't disturb English too much,
• "minor planets" is an old (before appropriate knowledge was available) misnomer for what should properly be called "planetoids",
• planetoids are less-than-planets, but big enough to impress us, including "asteroids",
• dwarf planet is ... (forget it),
• SSSB is an Extended TLA (ETLA).

Said: Rursus 11:06, 10 November 2007 (UTC)

Yeah, without some new discussion the template seems kind of pointless. I'm removing it. Bryan Derksen (talk) 08:48, 20 December 2007 (UTC)

## Merge or reorganization proposed

I think that asteroid and minor planet should be merged or at least substantially rearranged:

• The introductions to the articles themselves make clear that these terms are exact synonyms for a substantial number of people, especially those that use them regularly. There's no need to have two articles that describe the same thing just because there are multiple overlapping terms. When this happens, we just explain the terminology in a short paragraph, and if there is too much content, create subarticles based on coherent subtopics, rather than the less important distinctions of terminology.
• The distinction between "asteroid" and "Trans-Neptunian Object" is inconsistent with article titles like asteroid moon and asteroid family, which include TNOs.
• Things that are clearly in the wrong place:
• The section "Asteroid discovery" in asteroid applies to all minor planets.
• The section "Naming asteroids" in asteroid applies to all minor planets, including Pluto. Most of this material should be moved to minor planet names.
• After cleanup, the remaining sections in this article would be: "Asteroids in the solar system" (introductory material), "Asteroid exploration", and "Asteroids in fiction". Most of these refer to subarticles, and "Asteroid discovery", "Naming asteroids", and "Asteroid classification" would all actually refer to minor planet. We could either leave these extensive cross-references, or merge the articles. I don't think the result would be too long, especially since most of minor planet is currently a list of groups, which could be moved into a subarticle.

I thought that previous discussion here and at Talk:Asteroid was leaning toward a merge, but instead of just implementing the merge, for now I have re-added the merge tags. -- Beland (talk) 08:40, 2 January 2008 (UTC)

I do not agree that previous discussion was leaning toward a merge. In fact, it seems abundantly clear that there is no consensus, and to procede with a merge in this situation invites a rapid revert.Taquito1 (talk)
I should also note that Asteroid belt has semi-duplicative discovery and exploration sections (the history section oddly refers to Definition of planet, where more content is hidden) but is missing reference to the long list of groups here at minor planet. -- Beland (talk) 09:00, 2 January 2008 (UTC)

It amazes me that people would seriously entertain the idea of merging asteroid and minor planet! Ask anyone on the street, "What killed the dinosaurs?" Are they are likely to tell you, "A minor planet"? Of course not! How utterly pedantic to think that, because asteroids are minor planets, or vice versa, there must be just one article. Shall we eliminate the article on Africa because it is a continent? Or, more to the point, shall we eliminate the article on "house", because it is just a common, vulgar, term for the much more correct "domicile"? This reminds me of the tiresome argument over the use of the term "organic", as in "organic food" versus "organic chemistry"--the nerds always claim some imagined, exclusive right to the word; "...it must be a hydrocarbon...!", but the term "organic farming" has its own right to existence independent of the narrow limits such people would impose on it. English would be a dreary language indeed if the minor planet exclusivists had their way! And I have nothing against minor planets--it is term with meaning and usefulness. Is there overlap? Of course! And what is wrong with that?Taquito1 (talk) 19:37, 12 January 2008 (UTC)

This reasoning is almost idiotic. It does not matter what a person on a street would tell you. If you ask the same person weather Ploto is a planet he/she would most likely say yes. If you ask what are platinum or gold used for, the answer will definately be jewelry. They could not care less that because of their superficial attitude, it costs more for scientists to use platinum for the-actually-useful catalysis; they care only to show off to similarly superficial individuals. Popular/superficial culture SHOULD NOT INCLUENCE the content of an encyclopedia. Piss! Nergaal (talk) 04:32, 26 January 2008 (UTC)
Thank you for the "almost"! I hope you put more spelling care into your 8,000+ contributions (done generally at a rate of one per minute--you take the admonition to "save often" way too seriously) when they are articles instead of discussions! Is English a second language for you? Anyway, to get to the point, your example appears to be a suggestion that gold and platinum should be merged into the article on catalysts, rather than any refutation of my reasoning. And actually, I think it DOES matter what the person on the street thinks, since I do not entertain the elitist pretensions you appear to. I do not have the subtlety of knowledge to know whether "asteroid" or "minor planet" is preferred by the best scientists in the field, but I do know that "asteroid" is far more firmly entrenched in the common vernacular--and psyche--at the very least. And, perhaps more significantly, "asteroid" appears in virtually all of my text books that cover the topic, while "minor planet" does not; and where "minor planet" appears, it is generally STILL overshadowed by "asteroid". How, in this situation, could we possibly justify a merge?! And take a look at the prominence and recognition of the "asteroid" article compared to the "minor planet" article; that alone is telling. Unless someone satisfies these concerns, I will delete the merge templates when I return. —Preceding unsigned comment added by Taquito1 (talkcontribs) 05:35, 4 February 2008 (UTC)

## Groups out to the orbit of earth

Why are Vulcanoid asteroids listed in this section given they are hypothetical?? If it is considered this entry should remain then at least some explanation should be given as to why it is appropriate to include such hypothetical items. —Preceding unsigned comment added by Eldumpo (talkcontribs) 22:06, 31 January 2008 (UTC)

## No

Dont merge them these are two totaly different topics we are talking about!!!

Indeed. These are two different topics entirerly. Leave them in seperate articles.

Speaking as a completely unqualilfied layman, the merge proposal seems odd to me. Conceptually it seems to me that there must be a definitional difference between a minor planet (which orbits a star) and an asteroid (which need not). I think lay people would normally consider these to be complete different things. Everyone knows asteroids revolve around the sun in the Kuiper belt, and that some asteroids get trapped by planet gravity and become moons, but it seems to me that there is still a difference. If there was a merge, I suspect that the introduction paragraph would get hijacked providing some highly technical explanation as to why astronomers consider asteroids and minor planets to be the same thing. --Legis (talk - contribs) 12:38, 7 March 2008 (UTC)

## Merge

In order to facilitate bring the asteroid article up to FA at some point into the future, I was "bold" and took the initiative to merge the asteroid and minor planet articles. The majority of the minor planet article concerned "asteroid groups", so that has been moved into a separate article, asteroid group. What little remained was heavily redundant with the asteroid article and I saw little reason to keep them separate. But the content can be readily moved to the minor planet page, if that is the preferred direction. Thanks.—RJH (talk) 19:17, 11 April 2008 (UTC)

Since most of this material went to asteroid group and asteroid group had no history before now, I've turned this merge into a move in order to preserve edit history. Bryan Derksen (talk) 02:34, 19 April 2008 (UTC)

'Bold' again--'asteroid group' includes many populations not considered asteroids (KBOs, SDOs, etc.). Therefore 'Groups of minor planets'. ("Populations" might be better.) kwami (talk) 00:02, 29 September 2008 (UTC)

I, too, was bold: when I read the article, it struck me as a very good list article, not a C-class standard article. So, I changed the article's name to reflect its content. hike395 (talk) 17:48, 17 January 2009 (UTC)

## Thule group has grown!

It now has 3 members, see http://adsabs.harvard.edu/abs/2008MNRAS.tmp.1068B

--115.128.7.77 (talk) 10:30, 15 December 2009 (UTC)

## catch-all term?

Does there exist a catch-all term for all SSSBs/minor planets with semi-major axes smaller than those of the asteroids of the asteroid belt? --JorisvS (talk) 23:24, 31 August 2011 (UTC)

S.t. along the line of inferior planet maybe. — kwami (talk) 00:02, 1 September 2011 (UTC)