Talk:Pluto/Archive 5

Use the CORRECT name instead of the colloquial name
This celestal body doesn't have any other name that 134340 Pluto. There are tons of examples of Wikipedia articles about celestal bodies using the complete name with the number: 99942 Apophis, 90377 Sedna and way too many to list all of them. Redirects are there to ensure that those looking for it under its old name will find it under its new name. Even though it remains ordinary known as Pluto this article should use the correct name. Canjth (talk) 02:13, 26 November 2007 (UTC)
 * Check through the archives; this has been discussed at length on numerous occasions, and a consensus was developed in conjunction with a guideline for handling dwarf planets. Incidentally, the name of the object is simply "Pluto" - the "134340" is a numeric designation, and doesn't change the name. In a similar fashion, "90377 Sedna"'s name is "Sedna", and its numeric designation is "90377". If Sedna is recategorized as a dwarf planet, the article will be moved to Sedna or Sedna (dwarf planet). Hope this helps. --Ckatz chat spy  03:35, 26 November 2007 (UTC)

The *correct* name would be Pluto (dwarf planet). To be known as Pluto is to incorrectly suggest it is a (dynamically dominant) major planet. The correct name for Ceres is Ceres (dwarf planet) even though it is also known as 1 Ceres. I do think Pluto should be moved and re-directed to the correct Pluto (dwarf planet). Pluto may never get its major planet status back. -- Kheider 17:59, 4 December 2007 (UTC)
 * The only purpose of moving to Pluto (dwarf planet) would be to disambiguate. There does not appear to be a need to add the disambiguation suffix.  Pagra shtak  18:20, 4 December 2007 (UTC)
 * Agreed. Ceres would be at Ceres if not for the need to disambiguate; in the case of Pluto, the astronomical object is by far the dominant use of the term and as such claims the undisambiguated title. (The title doesn't make any suggestions about the status, in the same way that Mercury's location at Mercury (planet) shouldn't be taken as a suggestion that it any is less important than the other (undisambiguated) planets.) --Ckatz chat spy  20:59, 4 December 2007 (UTC)
 * How about the article about the RMS Titanic? Nobody ever refers as such to the Titanic, but Wikipedia still uses the correct name. Note that in the RMS Titanic article, it is only designated "Titanic" in the article, which would also be correct for Pluto (to avoid complicating the designation and confusing readers) but the title should respect the correct name assigned to celestal bodies. Canjth (talk) 03:21, 12 December 2007 (UTC)
 * Except that Pluto's correct name is not "134340 Pluto", it is "Pluto". It also happens to have the number 134340 in the Minor Planet Catalogue.  For small solar system bodies, Wikipedia has the convention that the article should be listed along with its Minor Planet number.  However, this convention does not hold for Dwarf Planets: after extensive discussion last year, it was decided that Dwarf Planets should be disambiguated via the term "(Dwarf Planet)" after their name, instead of via the Minor Planet number.  At the same time it was decided that Pluto did not need disambiguation. Bluap (talk) 04:21, 12 December 2007 (UTC)


 * Oh, leave it friggin BE! It got it's planet's status taken away from it.. Jeez, just cuz some stuffy people felt the need to reclassify the friggin thing and confuse the heck out of a lot of people for no reason other than inflated-ego self-satisfaction (And that IS why, because honestly, who does it effect to keep calling it a planet?) doesnt mean you have t change the wiki page too. Just let it go, already.--98.18.57.173 (talk) 11:50, 18 December 2007 (UTC)
 * Um, it's "affect", not "effect". [grammar geek mode off] The decision wasn't about ego, it was about coming up with a definition of planet that would prevent the Solar System being swamped with new worlds. If Pluto is a planet, then so are Eris and Ceres. If Eris, Ceres and Pluto are planets, then so are Quaoar, Sedna, Orcus, Ixion, Varuna and potentially hundreds of other unnamed and undiscovered objects. Are kids supposed to memorise all of them at school?  Serendi pod ous  17:51, 18 December 2007 (UTC)

✅
 * Support move to proper name, 134340 Pluto--Heliac (talk) 13:22, 10 January 2008 (UTC)
 * ❌ ...and I moved it back. Please get consensus before making this move. --Onorem♠Dil 13:32, 10 January 2008 (UTC)

Oppose. Dwarf planets such as Ceres are not listed by their minor planet designations, as per long-established Wiki consensus.  Serendi pod ous  13:33, 10 January 2008 (UTC)

OMG LOL please add this image
http://img140.imageshack.us/img140/706/poorplutoxp4.jpg lol please someone find a way to add this image to the article, maybe under the planetary status controversy paragraph, or you can add it to the 2006 definition of planet article —Preceding unsigned comment added by SquallLeonhart ITA (talk • contribs) 21:01, 6 December 2007 (UTC)
 * Doubt we could, since a) it's probably not public domain and b) it would have to have some noteworthiness beyond just being funny.  Serendi pod ous  05:14, 9 December 2007 (UTC)

I'd say it's note-worthy.. Thats certinly how _I_ felt when those stuffy ba$tards took away it's status. I dont care WHAT they say, Pluto is Pluto not 2356456w465pluto or any other crap. It is and always will be a planet, and they can go to Venus.--98.18.57.173 (talk) 11:45, 18 December 2007 (UTC)


 * If anyone wants to determine the availability (legally) of the photo, I support, albeit mildly, it's inclusion in the controversy section. It's just too good to pass up. atakdoug (talk) 21:45, 8 January 2008 (UTC)
 * It can't be included; it is copyrighted. If we got the permission of the original artist, then yes we could include it, but we'd need some kind of academic rationale to do so, and I can't think of an academic reason to include it.  Serendi pod ous  13:56, 10 January 2008 (UTC)
 * Facebook marketplace go follow me on facebook and my grandpaw joe he loves tiktok and ice cream with pickles ,and john wayne caseroul. Bold 2600:387:C:2D11:0:0:0:1 (talk) 15:33, 25 April 2022 (UTC)

name
we should probably say something about when Pluto received the MPN designation 134340, since if it had been numbered in order of discovery, it would have the number of 1164 Kobolda. — kwami (talk) 01:20, 29 December 2007 (UTC)
 * Moved a setence from Definition of planet over here. Simpler because it's already cited. Serendi pod ous  02:35, 29 December 2007 (UTC)

When is something NOT a planet?
Let me see if I understand this: Pluto, and on a related topic Ceres and Eris are NOT planets because they're too small. Isn't that a bit like saying midgets aren't human? Scientists can't just change the definition of a word because they feel like it. By the original definition, if it orbited the sun it was a planet, so who's really to say Pluto isn't? Zillakilla (talk) 14:59, 9 January 2008 (UTC)
 * So, the Cassini spacecraft was a planet when it orbited the Sun, and ceased to be a planet when it entered orbit about Saturn? We have to draw the line somewhere. If scientists cannot change the definitions of words, then we should restore the meaning of the word planet, not to your definition, which some scientist came up with, but to its true original meaning: "a light that wanders in the sky". The Sun and the Moon are therefore planets. kwami (talk) 23:08, 9 January 2008 (UTC)
 * (e/c) See 2006 definition of planet - it's not the size for the sake of it - poor Pluto fails the condition to have "cleared the neighbourhood" (which is somewhat related to the body's mass, but not solely dependent). Миша 13 23:09, 9 January 2008 (UTC)


 * It's all a conspiricy you know. The IAU is being cleverly manipulated by dieticians who are using poor lil Pluto as nothing more than a pawn in thier campain against obesity.  You see when Pluto was rightfully a planet, My Very Excellent Mother Just Served Us Nine Pizzas, now My Very Excellent Mother Just Served Us NOTHING!  Those evil bastards!  —Preceding unsigned comment added by 87.194.30.174 (talk) 02:18, 13 May 2008 (UTC)

Radius, Diameter differ in citations used
Information in the article differs from the citations used:

Since the sciencemag.org article is from 1987, perhaps its citation could be dropped. Of course, this is assuming NASA keeps their information up-to-date. Fehlschlag (talk) 15:22, 20 January 2008 (UTC)


 * Oh, nevermind! Once I actually spent time carefully reading, I realized the second one is a historical citation. Guess I should always have a nice microbrew before reading. On the bright side, I learned how to use a basic wikitable..., Cheers! Fehlschlag (talk) 02:36, 22 January 2008 (UTC)

Picture
Should this image be used? I noticed that the same image was removed from List of solar system objects by radius for not being a free use pic, should it also be removed from here? Sethhater123 (talk) 03:02, 22 January 2008 (UTC) Sethhater123
 * This article can make a case for fair use, since it is the best picture of Pluto currently available. That doesn't really apply to the radius article.  Serendi pod ous  04:14, 22 January 2008 (UTC)

Free concept image available


I uploaded a concept image of Pluto to Commons, which I cropped from Image:Plutonian system.jpg. The image is in public domain, as it was created by NASA, and I think it should replace the infobox image of Image:Pluto.jpg, which is non-free. Regardless, it should be in the article somewhere, but I'm not sure where exactly. – Dream out loud (talk) 02:17, 25 February 2008 (UTC)
 * A free concept image is not better than a non-free photograph. The image in the infobox should stay. Agree that the concept image should be somewhere in the article though. --GW_SimulationsUser Page 02:26, 25 February 2008 (UTC)
 * That looks like Ganymede! It's fantasy: Why should we include it? Unless we have a section on representations of Pluto in art? kwami (talk) 02:41, 25 February 2008 (UTC)
 * I prefer real photos. We should not give readers the false impression that we have high resolution photos of Pluto.  Ganymede (moon) seems to be used often as a stand in for Pluto.  But if you want fake Pluto's you can also use Iapetus (actual photo) and Oberon (with Pluto overlayed on it). -- Kheider (talk) 04:29, 25 February 2008 (UTC)
 * Agreed. It's fantasy. It has no encyclopedic value, and, as Kwami pointed out, it looks like Ganymede, which would be misleading.  Serendi pod  ous  08:38, 25 February 2008 (UTC)

Get a Different Image!
Please get a different picture of Pluto. That crappy picture look like a freakin' disco ball for heaven's sake. —Preceding unsigned comment added by AaronV28 (talk • contribs) 23:02, 8 March 2008 (UTC)
 * You're looking at the best science has to date. It will be updated as soon as possible... but that won't be until 2015, when New Horizons gets to Pluto. --Ckatz chat spy  23:38, 8 March 2008 (UTC)
 * Exactly, if anyone want's a better one, why don't they build a spaceship, fly out there and take one themselves, the whiny bums! —Preceding unsigned comment added by 87.194.30.174 (talk) 02:07, 13 May 2008 (UTC)

Planets Suck?
This "celestial body" SHOULD be a planet. The definition of a planet is if it owns the space around it. It is thought to be that pluto does not own the space around it, well, i disagree....I am 99% positive that if an asteroid passed close enough Pluto would suck it in (per say) because it is the 10 largest thing in within a certain area of the sun. So that brings us to the question of space Pluto should not have the same spacial area as ANY of the other planets because it is much smaller. The space it owns should be considered as 1/9 of the size of the of Earth's. It is my belief that they are giving Pluto the same formula of the AMOUNT of space owned by it as they are the other planets.Blackstar66 (talk) 04:34, 3 April 2008 (UTC)


 * Any asteroid passing too close to a larger, more massive body will be sucked in. That does not make the larger body a planet. -- Kheider (talk) 04:47, 3 April 2008 (UTC)
 * In fact, Blackstar66 is pretty close to the reason why Pluto is not a planet. The 8 planets "own" a space that stretches all the way round the sun in their whole orbit (plus other potential orbits nearby).  Pluto, on the other, is a lot smaller, and its orbit is a lot bigger.  This means that the size of space that Pluto "owns" isn't big compared with its own orbit, and is therefore classified as a Dwarf Planet.  A better example is Ceres: in order to be a planet, Ceres would have to "own" the entire asteroid belt.  This concept of "ownership" is described mathematically by the Stern-Levinson parameter (see the table in Cleared the neighbourhood): roughly the size of the region where the body is gravitationally dominant, divided by the size of the orbit.  You can see that there is a huge gap in values between that of Mars (the least dominant "planet"), and Eris (the most dominant "dwarf planet"). Bluap (talk) 19:13, 3 April 2008 (UTC)

Trimming
The article is getting long. There is a fair amount that can be trimmed. In Pluto, there is too much discussion of KBOs that do not apply to Pluto directly. "Rudolf" and "Easterbunny", while amusing, add nothing to the discussion of Pluto. It's enough to say that there are other moons without a detailed listing. The Pluto section could also be cut, relying on the main article. I'd like to suggest that a few things be done. Novangelis (talk) 16:41, 24 April 2008 (UTC)
 * 1) Keep things concise and let the main articles carry the lesser details.
 * 2) Break the KBO data into pre and post 2006 IAU sections. Any data available after the decision could not have impacted the decision making process. The newer discoveries should be subjected to a stringent "is this relevant to Pluto?" test.
 * 3) Consider the new article Pluto's Planetary Status to focus the debate and stabilize the main article.

I agree that this article is long, but I wouldn't say it's getting longer. It is still shorter than Uranus, and has held steady at 82-84 K since its last major expansion in November. None of the KBO data are post-2006, so that's not a problem (there haven't been any major discoveries since Eris). I agree that the EL61 info is fairly redundant and can be removed. There are already two other articles dealing with the definition of planet debate; Definition of planet and 2006 definition of planet, so I don't think we need a third. I've trimmed the "Planet X" section a bit, but I don't think a proper history of Pluto's discovery can work without discussion of Planet X, since Planet X was Pluto's name for a while; it's even called Planet X on Tombaugh's discovery notes.  Serendi pod ous  17:52, 24 April 2008 (UTC)
 * Thank you. I guess I failed the standard of be bold, but sometimes discretion is the better part of valor.  I agree with everything you said, and your trimming definitely was surgical. Novangelis (talk) 21:53, 25 April 2008 (UTC)

Eccentric orbit?
The article says:


 * It has an eccentric orbit that takes it from 30 to 49 AU (4.4–7.4 billion km) from the Sun, and is highly inclined with respect to the planets. As a result, Pluto occasionally comes closer to the Sun than the planet Neptune does.

This makes it sound like the inclination is the reason it sometimes comes closer than Neptune. Isn't it really the eccentricity which causes that? Also, (almost) all orbits are eccentric. What makes this one interesting is the degree of eccentricity. Would it better to say:


 * It has a highly eccentric and highly inclined orbit. The eccentricity takes it from 30 to 49 AU (4.4–7.4 billion km) from the Sun, causing Pluto to occasionally come closer to the Sun than Neptune.

-- RoySmith (talk) 18:07, 5 May 2008 (UTC)
 * Works for me.  Serendi pod ous  18:10, 5 May 2008 (UTC)

Requested move
Pluto → Pluto (dwarf planet) — Its classified as a dwarf planet now. —  Electrical  Experiment 01:58, 25 May 2008 (UTC)

Survey

 * Feel free to state your position on the renaming proposal by beginning a new line in this section with  or  , then sign your comment with  . Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's naming conventions.


 * Oppose I oppose doing this. The planet Pluto is the primary topic of the term Pluto.  Primary topics do not need disambiguated titles. Miami33139 (talk) 02:51, 25 May 2008 (UTC)


 * Oppose. This title was decided upon after a long and tedious edit war. I have no interest in sparking another one. Leave it be.  Serendi <sup style="color:#bb0000;">pod ous  07:20, 25 May 2008 (UTC)


 * Oppose No reason given for unnecessary disambiguation. WP:POINTy. JPG-GR (talk) 07:37, 25 May 2008 (UTC)


 * Comment are you claiming that the dwarf planet is not primary usage? 70.51.9.216 (talk) 08:43, 25 May 2008 (UTC)
 * No; the claim is that Pluto is so well known as a planet (or dwarf planet) that it doesn't meed to be disambiguated. The idea is that hardly anyone typing "Pluto" into Wikipedia's search engine will be looking for the Roman god of the underworld or Mickey's dog.  Serendi <sup style="color:#bb0000;">pod ous  08:46, 25 May 2008 (UTC)
 * First-level bullet, my comment was for the proposer of the move, Electrical Experiment, not JPG-GR's response. Does the proposer claim that Pluto (dwarf planet) means that the dwarf planet is not the primary meaning in English. 70.51.10.75 (talk) 11:29, 25 May 2008 (UTC)


 * Oppose The article is not currently called Pluto (planet) so why move it to Pluto (dwarf planet)? This Pluto is clearly the primary use. — Lincolnite (talk) 16:14, 25 May 2008 (UTC)
 * Oppose This is clearly the most common usage of the word "Pluto". There was a large series of naming discussions shortly after Pluto was re-classified as a dwarf planet.  After much anguish, the current naming scheme was adopted.  I see no reason to change it. Bluap (talk) 19:49, 25 May 2008 (UTC)


 * Oppose - per previous discussion. This is the most common usage, there is no need to disambiguate. In what way is the current title inappropriate for a dwarf planet? I also move to close under WP:SNOW. --<font color="#115566">GW_SimulationsUser Page 21:39, 25 May 2008 (UTC)


 * Oppose I don't think we need to go through this again. I completely agree with Serendipodous on this one. shaggy (talk) 21:43, 25 May 2008 (UTC)


 * Oppose We don't say "Jupiter (planet)", and I think the same logic applies here. Wwheaton (talk) 23:44, 25 May 2008 (UTC)


 * Oppose. Pointless addition of a redundant disambiguator. Andrewa (talk) 06:58, 26 May 2008 (UTC)


 * Oppose No need for a disambiguate. All for GW Sim's suggestion of a snow close. Narson (talk) 14:24, 26 May 2008 (UTC)
 * Oppose It's status is irrelevant. WP:COMMONNAME applies. --Stephan Schulz (talk) 14:32, 26 May 2008 (UTC)


 * Oppose - It's alraedy been said, but this is a pointless disambiguation, Pluto's status is irrelevant to the title of the article, and this is a divisive move that should be prevented per WP:SOAP. Wilhelm meis (talk) 20:24, 26 May 2008 (UTC)


 * Oppose - people look for "Pluto", not for "Pluto (dwarf planet)". GrzegorzWu (talk) 08:32, 27 May 2008 (UTC)

Discussion

 * Any additional comments:


 * Unless this move is also to move Pluto (disambiguation) to Pluto, the there is no point to renaming this article to Pluto (dwarf planet). There is no need for the parenthetical phrase unless this is also about the planet no longer being the primary topic. older ≠ wiser 02:12, 25 May 2008 (UTC)

At least this time it was raised at WP:RM. The reason there's a redirect at Pluto (dwarf planet) is that a couple of years ago it was unilaterally moved. You need to dig pretty deep into the history to find this move but here it is. It was quickly moved back.

And there was at least one subsequent unilateral move, to a different location but on much the same rationale. There's another redir at (134340) Pluto, the story is a little more complex for this one but see Talk:Pluto/Archive 7, and the resulting redir was deleted but later recreated. And another move that was pure and explicit vandalism and doesn't even rate a link. Interesting. Andrewa (talk) 07:28, 26 May 2008 (UTC)
 * not so much interesting as it is the result of a very contentious discussion on where exactly someone should be able to find the article for the (now) minor planet 134340 Pluto. The general consensus was that "Pluto" had pointed to the planet, and that a reclassification to dwarf planet doesn't mean the object is any less notable. Someone searching for "Pluto" is going to be looking for the planet/dwarf planet most of the time, and a redirect/move doesn't do anything but raise a lot of tempers. Leaving it the way it is works, and saves us a lot of pointless arguing. shaggy (talk) 09:56, 26 May 2008 (UTC)


 * Well, it may not be interesting to you. But hopefully, this RM will provide some guidance as to the wisdom (or not) of further unilateral moves, and spare us more contentious discussion. Andrewa (talk) 09:12, 27 May 2008 (UTC)

I think it's time we closed this up. I'm planning to archive this page and then add a template about frequently raised discussions. That should, I hope, resolve this issue for the future.  Serendi <sup style="color:#bb0000;">pod ous  10:05, 27 May 2008 (UTC)
 * Good idea. kwami (talk) 10:14, 27 May 2008 (UTC)

Plutoid
Pluto was just named as a Plutoid, a small roughly spherical object orbiting beyond Neptune. It and Eris are the only two so far discovered. This page should be updated to reflect the new terminology. —Preceding unsigned comment added by 71.7.147.138 (talk) 20:56, 12 June 2008 (UTC)


 * It has already been added.(prototype) Being an official dwarf planet in hydrostatic equilibrium is far more important than being a plutoid (want a be dwarf planet) that has an absolute magnitude of (H<1) as observed with a telescope. The term Plutoid was created to simplify the requirement for creating a dwarf planet-like category. -- Kheider (talk) 22:56, 12 June 2008 (UTC)


 * Since Pluto is a Plutoid by definition, describing Pluto as a Plutoid in the lead seems about as useful as describing the Earth as an Earthoid. It remains to be seen if the general public or astronomers will adopt the term plutoid since it is merely a sub category of 'dwarf planet'. The category Plutoid was created in 2006,(Resolution 6) it just was not named until recently.(Plutoid chosen as name) -- Kheider (talk) 09:24, 20 June 2008 (UTC)
 * Well, Earth is a terrestrial planet, and all terrestrial means is "of or like the Earth."  Serendi <sup style="color:#bb0000;">pod ous  14:57, 20 June 2008 (UTC)

Pluto belongs to many categories: Former Planet, Dwarf Planet, Plutoid, Trans-Neptunian object, Kuiper belt object, Plutino, and Minor planet. It has also been referred to as an asteroid and comet. In the lead it is only important to mention 'dwarf planet'. -- Kheider (talk) 20:57, 20 June 2008 (UTC)

Who did it
MPC and his head Brian Marsden added Pluto to the MPC list of minor bodies (doing their own interpretation on IAU recommendation), so this was extension (some perceive it as overturning the vote which stated that Pluto is not minor solar system object) clearly unanticipated after the vote. GrzegorzWu (talk) 08:32, 4 June 2008 (UTC)
 * Sources? I have never heard of this particular controversy. It would be pretty silly to keep Pluto out of the catalogue, since if all dwarf planets were to be excluded, then Ceres would be too, and since Ceres is #1 in the catalogue, that would mean that every single object in the catalogue would have to be re-numbered, and thus that every scientific paper on every minor planet would instantly be made inaccurate. Since that was obviously impractical, I can't see how anyone could object to the move.  Serendi <sup style="color:#bb0000;">pod ous  09:01, 4 June 2008 (UTC)

IAU Dead Link
Under Pluto (Ref 96): "IAU 2006 General Assembly: Resolutions 5 and 6" is dead. This link is also used under dwarf planet (Ref 3) "Definition of a Planet in the Solar System: Resolutions 5 and 6" and cited 6 times. This does not help compare the definition (or background) of Plutoid and Dwarf Planet. Have I found the correct replacement link at: http://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf ? -- Kheider (talk) 17:51, 15 June 2008 (UTC)
 * I can't read it, since I don't have Photoshop, but if it resembles this press release, then yes.  Serendi <sup style="color:#bb0000;">pod ous  18:29, 15 June 2008 (UTC)
 * It's a pdf file; so you don't need Photoshop to view it, just the free Adobe Reader program. Jmsloderbeck (talk) 22:59, 19 June 2008 (UTC)

Rings on Pluto?
Does pluto even have rings. It seems like it does not have rings though, since no spacecraft ever visit Pluto we don't even know if pluto have rings or not. One of Saturn's moon Rhea might have rings.-- Freewayguy Call? Fish 21:40, 24 July 2008 (UTC)
 * We don't know. Some have speculated that it may be a possibility, given Pluto's violent past, but there's no evidence to support the idea.  Serendi <sup style="color:#bb0000;">pod ous  05:46, 25 July 2008 (UTC)
 * You should read this . Ruslik (talk) 10:30, 25 July 2008 (UTC)

Text-squeeze
The majority of the images in this article are in contravention of the manual of style: avoid sandwiching text between two images facing each other. There are so many images here that it is impossible to avoid this problem without removing some. Is it possible to cut down the images for the sake of readability, or is this just a compromise that the page-layout will have to live with?  Plasticup  <font color="#2A8E82">T /<font color="#2A8E82"> C 04:21, 24 August 2008 (UTC)
 * Fixed.  Serendi <sup style="color:#bb0000;">pod ous  19:33, 31 August 2008 (UTC)

Discovery of Pluto
This is indeed just a small side note, but the discoverer of Pluto was actually Percival Lowell. —Preceding unsigned comment added by 134.114.63.148 (talk) 15:43, 27 October 2008 (UTC)
 * No he wasn't. The article should make this clear. If it's not clear, then please let me know what you don't get, so I can rewrite it.  Serendi <sup style="color:#bb0000;">pod ous  17:09, 27 October 2008 (UTC)

Percival Lowell did not discover Pluto get that straight or I will copy paste the article that proves that wrong.Mrs.shipley (talk) 23:50, 27 October 2008 (UTC)


 * Once a question like this has been asked and correctly answered, can't we take it out? 70.19.50.219 (talk) 02:24, 14 January 2009 (UTC)Larry Siegel

Tombaugh discovered the Pluto through telescope in 1930. But before the actual discovery, the presence of Pluto was predicted by an Indian Teacher "Vyankatesh Bapooji Ketkar" in 1911. His paper was published in french magazine. The predictions about the distance from the Sun, mass of planet etc. were 99% correct. No other predictions match this accuracy.Gsuhas (talk) 03:50, 4 September 2008 (UTC)
 * No one predicted the existence of Pluto. Many people (not just Katkar) thought they had predicted the existence of Pluto, but it was later revealed that Pluto is too small to exert any noticeable gravitational influence. As it turns out, those "predictions" were based on faulty measurements of Neptune's mass. Pluto is tiny; its mass is only one five-hundredth that of the Earth. There is simply no way other than blind luck that anyone could have determined a mass that small without measuring it directly.  Serendi <sup style="color:#bb0000;">pod ous  06:14, 4 September 2008 (UTC)
 * I've added a mention of Ketakar's planet (actually planets) to a footnote in Planets beyond Neptune. Ketakar's predictions had nothing to do with mass, and Ketakar made no reference to mass at all. Serendi <sup style="color:#bb0000;">pod ous  10:43, 4 September 2008 (UTC)

On the Secret Doctrine, Blavatsky wrote about Pluto 100 years before it was invented. The citation is on page 408. I hope that is of relevance. --64.9.241.158 (talk) 23:14, 6 April 2009 (UTC)
 * Neither page 408 in the first volume of The Secret Doctrine, nor page 408 in the second volume mentions an undiscovered planet.  Serendi <sup style="color:#bb0000;">pod ous  08:23, 7 April 2009 (UTC)

"sacred to Pluto...Jupiter...and Neptune." The Romans wrote about it way before Blavatsky. She indirectly states Marcellus new about pluto in 212 and Prosperpine new about it. Prosperpine must have been an Atlantean.--64.9.241.158 (talk) 17:05, 8 April 2009 (UTC)

So because she mentioned the *god* Pluto, she predicted the *planet* Pluto? Okaaayy....  Serendi <sup style="color:#bb0000;">pod ous  18:09, 8 April 2009 (UTC)

Main image of Pluto
I suggest to show the image of Pluto in a smaller resolution in the article (maybe half the size it has now, or even smaller). This would not remove much (if any) information since the original has such a bad "resolution", and it would be much more pleasurable to look at. The fact that no better resolution exists is just as well illustrated by a small picture without visible resolution limits as by the current larger one. --Roentgenium111 (talk) 16:22, 26 September 2008 (UTC)


 * The image is the default size for an infobox; to reduce it there would look odd. That aside, the image also speaks to the fact that Pluto's distance limits what we know about it. --Ckatz <sup style="color:green;">chat <sub style="color:red;">spy  17:25, 26 September 2008 (UTC)

Why not add a black border so the image can stay the same size while reducing Pluto by half? I agree it would look better. kwami (talk) 22:24, 29 September 2008 (UTC)


 * That's a good suggestion. Could you do it? (I don't know how to edit images.)--Roentgenium111 (talk) 14:48, 30 September 2008 (UTC)

I just noticed that the direct image of Pluto (and Charon) from Hubble (given in the "Physical Characteristics" section) has a slightly better resolution than the main image: a square box around one of the photographed Plutos is about 60x60 pixels, while the main image has about 50x50 mono-coloured boxes. So we could just swap the positions in the article to have a nicer "main image", which would even include Charon. --Roentgenium111 (talk) 17:17, 30 September 2008 (UTC)


 * I just noticed that the image that claims to be Pluto and Charon from Hubble doesn't seem to actually include Charon, just mislabeled... --Patteroast (talk) 22:45, 30 September 2008 (UTC)
 * How do you know? --Roentgenium111 (talk) 14:56, 1 October 2008 (UTC)


 * He's right. The NASA text said nothing about Charon. Although they didn't actually label the two images, the point of the article was how much better the Hubble images were than anything which had come before. Also, the resolution of the two images was different. My inference is that the small image was pre-Hubble, or perhaps Hubble before its optics were fixed. kwami (talk) 17:51, 1 October 2008 (UTC)

Always night on Pluto
Is it always what we call "night" on Pluto. YouthoNation (talk) 21:56, 29 September 2008 (UTC)
 * No. At any time, half of Pluto faces the sun. Bluap (talk) 22:07, 29 September 2008 (UTC)


 * Given its axis at 120°, at high latitudes in winter, night must be decades long. kwami (talk)


 * But, to us Earthlings, it would still be night, even when the sun is out, because it's dark like night. YouthoNation (talk) 18:11, 30 September 2008 (UTC)


 * That's like saying it's always night in a cave. Not normally what people mean by the word. Dark like night, yes. kwami (talk) 00:34, 1 October 2008 (UTC)
 * And anyway, the Sun's still pretty bright at Pluto's distance; brighter than the full moon, so you can't really say it's always night.  Serendi <sup style="color:#bb0000;">pod ous  19:03, 1 October 2008 (UTC)

Please

 * In Russian section Pluto is featured article. Please add in article a template "link FA|ru". Article is protected...Startreker2 (talk) 00:02, 8 October 2008 (UTC)


 * Done. Congratulations! kwami (talk) 01:42, 8 October 2008 (UTC)
 * Many thanks. It is my article, I plan to translate into Russian all articles about planets of Solar system. Our articles on these themes bad...Startreker2 (talk) 06:32, 8 October 2008 (UTC)

Needing help with references
It seems all references here are to webpages. I need one done for a book that shows that Pluto was being doubted as a planet as far back as 1978. —Preceding unsigned comment added by MrInitialMan (talk • contribs) 16:33, 26 October 2008 (UTC)
 * See here, from December 1978 issue of the US magazine Astronomy: http://myweb.tiscali.co.uk/ianridpath/Pluto.pdf. It was the discovery of minor planet Chiron in the outer Solar System that first raised serious doubts about the status of Pluto, and that was back in 1977. Ian. 79.66.80.248 (talk) 11:02, 17 April 2009 (UTC)


 * In 1978, James Christy discovered Pluto's moon Charon, which allowed astronomers to measure Pluto's mass, and thus learn how small it was. That told them that Pluto was not Planet X, but I can't think of anyone who doubted it was a planet. That only started happening after 1992, when the Kuiper belt was discovered. Before then, there were a number of astronomers who decided that Pluto would be better described as a large comet rather than as a planet, but they were a small minority.  Serendi <sup style="color:#bb0000;">pod ous  16:43, 26 October 2008 (UTC)


 * Actually a lot astronomers doubted it was a planet when it was discovered because it was not large enough to show a disk like all the other planets. -- Kheider (talk) 16:57, 26 October 2008 (UTC)

Mass & Size
Article mentions (in Mass and size section)

 but at less than 0.2 lunar masses it is also smaller than seven of the moons

is it smaller in terms of size or mass or both? Padalkar.kshitij (talk) 18:00, 31 October 2008 (UTC)
 * Mass.  Serendi <sup style="color:#bb0000;">pod ous  18:15, 31 October 2008 (UTC)

Can somebody please dig through this complicated article, pick out (since I couldn't) the *actual diameter* of Pluto in layman's terms (say in miles, or feet, or even km would do), and then put that information at the top of the article? Talk about getting lost in the details. Science geeks, sheesh! Ya gotta admit it's pretty comical that this likely single most sought after bit of data has been *completely buried* and as far as I can tell doesn't even appear in the article! Heh heh. --99.245.216.229 (talk) 16:01, 5 November 2008 (UTC)
 * Well, Pluto's stats are listed right there in the infobox at the top of the page.  Serendi <sup style="color:#bb0000;">pod ous  16:23, 5 November 2008 (UTC)


 * Looking at the table of contents I think you want to read a section called Mass and size. -- Kheider (talk) 16:35, 5 November 2008 (UTC)

Well, just one thing about Planet X.
If Pluto did't make it as a planet, shouldn't we still look for another Planet X. It only makes sense. Not dollars, sense. :) I still think Pluto shouuld still be a planet.  My opinion. Sir gladwyn (talk) 18:45, 23 November 2008 (UTC)
 * Planet X doesn't exist, at least not the Planet X that Lowell speculated about. So there's no need to go looking for it.  Serendi <sup style="color:#bb0000;">pod ous  15:16, 28 November 2008 (UTC)

The thing is, the mass required to fit the criteria of a "planet" increases the farther you get away from the Sun. If there were a mass large enough out there, we would have found it by now, so no... we don't need to look for Planet X any more. We will continue to look for dwarf planets and other small bodies, but we are now certain that the Solar System only as 8 planets. Nathan McKnight -- Aelffin (talk) 19:57, 12 January 2009 (UTC)
 * That isn't strictly true; an object the size of Pluto or Ceres beyond the orbit of Neptune could be considered a planet if it was far enough away from other similarly-sized objects; it's just that from what we think we know about the outer Solar System, such an object seems unlikely to be found. It is however certainly true that if Lowell's Planet X (Ie an Earth-sized planet located roughly at Pluto's distance) existed, Mike Brown, at least, would have found it.  Serendi <sup style="color:#bb0000;">pod  ous  03:11, 14 January 2009 (UTC)
 * I thought the issue was that a Pluto- or Ceres-sized object wouldn't have enough mass to have cleared its orbit, and any object large enough to have done so would be obvious. Nathan McKnight -- Aelffin (talk) 02:09, 15 January 2009 (UTC)
 * Ceres and Pluto do not have the mass required to control/clear their orbits, but if their orbits did not have similar sized objects in them, one could argue that they were planets. -- Kheider (talk) 06:32, 15 January 2009 (UTC)
 * Hmm. I suppose, but since the IAU definition reads that the object in question "has 'cleared the neighbourhood' around its orbit" rather than "occupies a cleared orbit" or somesuch, the way I read it, the definition seems to be saying that the planet itself has done the clearing, thus implicitly must have the mass to do so. An academic distinction perhaps. Nathan McKnight -- Aelffin (talk) 12:20, 19 January 2009 (UTC)
 * I think the concept of "clearing the neighborhood" makes an implicit assumption about Solar System formation that any object in an empty orbit must be massive enough to have cleared it. By the logic of the formulators of the phrase, we would never find an object the size of Ceres or Pluto in an empty orbit, which would mean we'd have to scrap the definition if we ever did.  Serendi <sup style="color:#bb0000;">pod ous  12:35, 19 January 2009 (UTC)
 * I'm pretty sure the idea of clearing the neighborhood is based on Stern & Levison's calculations of gravitational scattering (Λ=kM^2/P), which gives it a little more theoretical weight than the circular reasoning you suggest. As far as I can tell, their logic doesn't imply that an object with a critically small Λ-value cannot be in an otherwise empty orbit, merely that the orbit cannot have been cleared by that object--they don't rule out, for example, later capture of a small object into a previously empty orbit--making the act of clearing the orbit by the body, and therefore the body's critically large Λ-value, to be the crucial factor, rather than simply the presence of the body in a cleared orbit. So, if an object too small to have cleared its orbit were found in a cleared orbit, it still wouldn't be a planet. Nathan McKnight -- Aelffin (talk) 15:50, 19 January 2009 (UTC)
 * Computer simulations suggest that our solar system is dynamically full, with no room left to insert another planet in a stable orbit between the existing ones. (Soter, The Utility of the Dynamical-Based (IAU) Definition, last paragraph) This is a fundamental concept that separates the required objects from the not so required objects. -- Kheider (talk) 17:05, 19 January 2009 (UTC)
 * True, but this concerns objects beyond Pluto's orbit, where the gaps have yet to be filled in.  Serendi <sup style="color:#bb0000;">pod ous  21:08, 19 January 2009 (UTC)
 * The Nice model seems to suggest that the proto-planetary disk must have been truncated at roughly 30 to 35AU so that Neptune would stop migrating at its observed location of 30AU. The Kuiper belt region as observed today would have originally been devoid of most of the current objects. So for the time being it does not appear that any solar system body beyond Neptune dominants it's region. -- Kheider (talk) 22:38, 19 January 2009 (UTC)

near-circular orbit about 33 AU from the Sun
The article does not seem to mention the fact that Pluto was likely captured into a 3:2 resonance when Neptune migrated outward. Somewhere under the Orbit section, I would like to add a statement that says something a long the lines, "It is possible that Pluto had a near-circular orbit about 33 AU from the Sun before Neptune's outward migration started to perturb Pluto into a resonant capture." REF: The origin of Pluto's orbit (Malhotra 1995) (See Leftside middle of Page 6) -- Kheider (talk) 18:50, 12 January 2009 (UTC)
 * This publication is too old, and the model used in this article is rather simplistic. It is not possible to find out what orbit Pluto had had before Neptune started to migrate. Orbital evolution of Pluto during migration was chaotic. Ruslik (talk) 20:21, 12 January 2009 (UTC)


 * Yes and no. Pluto would have formed in a circular orbit like other bodies of the solar system.  Given that it is an intermediate sized body, it would not have been perturbed too much by other bodies until Neptune started pushing it around.  The exact evolution Pluto's orbit took is unknown.  But the current theory is that Neptune migrated outward and it is almost certain that Pluto started out with a semi-major axis closer to ~33AU (give or take) than the current semi-major axis of 39AU. I still think something should be mentioned about the likely migration of Neptune and where Pluto may have been before the migration. 1995 is not that old of a paper, and for a general overview you only need a simplistic model.  Many of the references used in the orbit section actually come from even older papers. -- Kheider (talk) 21:22, 12 January 2009 (UTC)

Line in the article referring to Pluto as a planet in passing should be fixed
I'd do it myself, but the page is protected. The line is the last one in the paragraph describing Pluto's name in other languages:

Vietnamese also uses the Vietnamese name for Yama (Diêm Vương) as the name of the planet.

I think in this case the entire "as the name of the planet" clause is redundant given the context.

Cheers.209.112.199.164 (talk) 00:52, 4 February 2009 (UTC)
 * reverted.  Serendi <sup style="color:#bb0000;">pod ous  08:24, 4 February 2009 (UTC)

Pluto! What happened to him???
Recently sientists classified Pluto as a dwarf planet and not a real planet. Some scientists stil disagree with this decision I also being an informed 12 year old agree. Now teachers cannot teach the same curriculm in the area of outer space. I wish pluto was still a planet because now we cannot say My Very Excelent Mother Just Sent Us Nine Pizzas to remember Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto!!! —Preceding unsigned comment added by 71.156.87.75 (talk) 20:52, 6 February 2009 (UTC)
 * I would recommend watching this documentary, made before the IAU's definition. It covers a lot of the issues:, , , ,  Serendi <sup style="color:#bb0000;">pod  ous  21:03, 6 February 2009 (UTC)

Planet status legislated by Illinois
Illinois has passed a resolution declaring Pluto to be a planet. http://www.chicagotribune.com/news/nationworld/chi-talk-pluto-07-mar07,0,1105188.story I'm not really up to speed on whether or not this kind of current event/novelty warrants inclusion here so I will leave it to the WikiNatives to include or not.


 * This is by the US Gov in a field they known nothing about.  Besides the US Gov is not a reliable source for anything to do with thinking. -- Kheider (talk) 11:10, 8 March 2009 (UTC)
 * First, WP:OR has nothing to do with. WP:OR is when somebody tries to use Wikipedia as a primary point of dissemination for "knowledge" not previously published elsewhere. The fact that this resolution was passed has been adequately mentioned in reliable non-Wikipedia sources that we can report it if we find it relevant.
 * Second, the United States government has nothing to do with it; it's purely an Illinois thing.
 * Third, the Illinois legislature is not used as a source here, so its reliability is not relevant. It is the subject of the report. –Henning Makholm (talk) 13:03, 8 March 2009 (UTC)
 * It's already been added. So now Pluto is a planet in the two states Tombaugh called home, New Mexico and Illinois, but, oddly, not in the state where he was born, Kansas, although to be fair, given that state's record with accepting science, they probably think that, since planets aren't mentioned in the Book of Genesis, to even acknowlege their existence is to engage in heathen sky-worship.  Serendi <sup style="color:#bb0000;">pod ous  12:21, 8 March 2009 (UTC)
 * This is just a non-binding resolution of the state's senate. It means nothing. Any group of people can gather together and declare what they want. Ruslik (talk) 12:35, 8 March 2009 (UTC)
 * Irrespective of how scientifically irrelevant these resolutions are, they still have encyclopedic interest, being representative of the scale and spread of the planetary-redefinition controversy outside scientific circles. On a scale from "crazy guy with an Internet petition addressed to noone in particular" to the Indiana pi bill, I'd say we're more than halfway there. That counts as notable in my eyes. –Henning Makholm (talk) 13:03, 8 March 2009 (UTC)

Direct images
I don't think the images captioned "Direct images of Pluto from the Hubble Space Telescope" actually deserve that description. Is it realistic that Hubble would be able to resolve Pluto's circular contour this sharply without giving better resolution of surface details? The Hubblesite describtion, as far as I understand it, says that an albedo map was derived from a series of different Hubble images, and that the image in the article is a digital projection of that map. I wouldn't call that "direct", though I'll concede it is more direct than the occultation-derived image in the infobox. –Henning Makholm (talk) 18:01, 16 March 2009 (UTC)
 * I used the language from that article in the caption, but on second thought, the nature of what is meant is not clear. It is changed to be more specific now, but we probably need an article describing these modern imaging techniques. Fotaun (talk) 15:29, 17 March 2009 (UTC)

The "Cultural history" section
This section needs to be restored back to its original locations. The demise of Planet X is not "cultural", it is an important scientific discovery that needs to be made clear at the top, because there still are people out there who think Planet X exists. The debate about Pluto's planet status should have its own section, as it is the one thing most people know about Pluto.  Serendi <sup style="color:#bb0000;">pod ous  15:55, 17 March 2009 (UTC)
 * I moved the Plant X section back, but I still think the article was better the way it was. The debate about Pluto's planet status shouldn't be a subsection.  Serendi <sup style="color:#bb0000;">pod ous  16:12, 17 March 2009 (UTC)

typo
In the Classification section there is a typo than is spelled: thant —Preceding unsigned comment added by 92.235.181.3 (talk) 13:34, 20 March 2009 (UTC)

Pluto structure picture
That picture is way older than 2009, and I'm not sure I believe it, since it flies in the face of what we think we know about the Kuiper belt. That Pluto contains rock is almost certain, but that it contains iron or nickel seems virtually preposterous. And since noone knows what Pluto's internal structure is like, it seems better to stick with current consensus.  Serendi <sup style="color:#bb0000;">pod ous  16:39, 20 March 2009 (UTC)
 * The image is from NASA, while the other has no source. Fotaun (talk) 17:07, 20 March 2009 (UTC)
 * But it doesn't reflect what is in the article. If you can find me a credible source that says that Pluto has a core of nickel/iron then that picture can be included. Other than in that picture, I have never encountered that hypothesis before, and I don't see it in the image's source page. All its says is that Pluto has a surface of methane ice.  Serendi <sup style="color:#bb0000;">pod ous  17:11, 20 March 2009 (UTC)
 * I don't think its very good either, but the other picture has no source. Fotaun (talk) 17:14, 20 March 2009 (UTC)
 * It has no source because it was created by a wiki user using information in this article. Ergo it reflects information in this article. NASA is primarily an engineering organisation. Their solar system site is notoriously unreliable and contains a lot of factual errors, so I wouldn't trust anything from there.  Serendi <sup style="color:#bb0000;">pod ous  17:19, 20 March 2009 (UTC)
 * The image was created by the NASA funded Lunar and Planetary Institute, according to NASA. The other image was created by a Wikipedia user from a Wikipedia article, according to another Wikipedia user. Fotaun (talk) 18:19, 20 March 2009 (UTC)
 * It doesn't matter where that picture came from. It is what it is saying that I have a problem with. No source I can find backs up that picture's claim that Pluto has an iron/nickel core. This article says that Pluto has a core of rock and ice, which that picture contradicts without offering an alternative explanation. Unless an alternative explanation can be found, then I don't want it in the article.  Serendi <sup style="color:#bb0000;">pod ous  18:22, 20 March 2009 (UTC)
 * Where an image comes from does matter, and the work of a professional science organization is a more credible and responsible choice for this article. Fotaun (talk) 19:17, 20 March 2009 (UTC)
 * The picture from LPI grossly misrepresents the structure of Pluto. The core's radius should be about 70% of that of Pluto (I added a source and numbers). The LPI's picture shows less than 10%, which is plain wrong (such a core would have the mass less than 0.1% of Pluto's). In addition, while it is true that any rocks contain Fe/Ni, there is no evidence that they have separated from silicates inside Pluto, as that picture implies. So LPI' picture should not be in this article. Ruslik (talk) 09:50, 21 March 2009 (UTC)
 * The LPI image was produced by a professional science organization, and deserves to be shown in the article. Fotaun (talk) 18:44, 21 March 2009 (UTC)
 * Not every image from LPI deserves inclusion into articles. This one definitely not. Ruslik (talk) 18:56, 21 March 2009 (UTC)
 * Ruslik, I understand your points about LPI and the latest research on Pluto's structure, but I can't in good conscious support an image with no sources and of unknown origin. What I would actually prefer, is if we made a new image incorporating the latest research, but that clearly lists its sources. Fotaun (talk) 19:09, 21 March 2009 (UTC)
 * Images are not required to have sources, they are exempt from WP:OR. In any case the new image will be virtually indistinguishable from the current image. This image only demonstrates approximate proportions of different layers inside Pluto, and you in principle can not draw anything better. Ruslik (talk) 19:18, 21 March 2009 (UTC)
 * I think we could make a better image, at least one with actual references. Even if its not required, its bad science and bad research not to. Fotaun (talk) 19:35, 21 March 2009 (UTC)

We can replace the img w st better if and when we have st better. Meanwhile we can keep the existing img. It corresponds to RS's on the composition of Pluto. I agree that we shouldn't have an img that contradicts RS's regardless of whether it comes from NASA. kwami (talk) 19:42, 21 March 2009 (UTC)
 * The other image came from the Lunar and Planetary Institute not NASA. Fotaun (talk) 20:01, 21 March 2009 (UTC)

As a temp fix, should we photoshop (or wiki-combine) the two images into a single image showing both models, ie:
 * LPI's image was probably made ~30 years ago, when the density of Pluto was thought to be about 1 g/cm3. Ruslik (talk) 20:26, 21 March 2009 (UTC)
 * Ouch. I did not realize that it was that old. Do you have a cite showing how old the image is? -- Kheider (talk) 20:32, 21 March 2009 (UTC)
 * I will try to find. Ruslik (talk) 20:36, 21 March 2009 (UTC)
 * It looks a simplified depiction of the undifferentiated ice/rock model for Pluto, which is less favored but sometimes mentioned. (such as in this book). Fotaun (talk) 22:22, 24 March 2009 (UTC)
 * Those images show a core substantially larger than the one in the image, and of rock, not iron/nickel.  Serendi <sup style="color:#bb0000;">pod ous  22:24, 24 March 2009 (UTC)
 * Its an example of the two models, not a reference for the LPI image. There is variation in differentiated models for Pluto's interior as well. Fotaun (talk) 17:53, 26 March 2009 (UTC)
 * But nowhere is there any reference to the completely bizarro idea that Pluto has an iron/nickel core. That may have been an idea back in about 1977, when we still thought Pluto was a terrestrial planet, but it's certainly not true now. Pluto having an iron/nickel core completely contradicts every modern hypothesis on Pluto's formation and evolution. It's simply not accepted now. You have yet to provide anything, apart from this one image, that says that this idea is supported by anyone.  Serendi <sup style="color:#bb0000;">pod ous  18:09, 26 March 2009 (UTC)
 * I have tried to avoid suggesting how well either theory is supported, I was just trying to present material from a professional source to the reader. Fotaun (talk) 18:45, 26 March 2009 (UTC)
 * Please see the term Appeal to authority. Science is evidence-based. It doesn't matter who has an idea about anything in science, if there is no evidence to back it up, it has no scientific value.  Serendi <sup style="color:#bb0000;">pod ous  18:59, 26 March 2009 (UTC)
 * This perspective was for writing an encyclopedia, not making a scientific judgment. Fotaun (talk) 19:04, 26 March 2009 (UTC)
 * The MO for writing this encyclopedia is to back up our claims with citations and references. The only citation you have provided for that image says nothing about its iron/nickel core. Without such information, the image is unreliable. Serendi <sup style="color:#bb0000;">pod ous  19:17, 26 March 2009 (UTC)
 * It says "iron-nickel alloy, rock" which is not the same thing as a "iron/nickel core". I have not provided citations for either image, this was to point out there are two main theories about Pluto's structure, and that the differentiated model is favored. Fotaun (talk) 19:33, 26 March 2009 (UTC)
 * Yes, but where did the iron/nickel come from? There's nothing about it in any dusssion of KBOs I've ever read, so to be included there would have to be some kind of explanation to back it up. It is mentioned nowhere in the article and I can't find any papers discussing it. This image contradicts everything modern science says about the Kuiper belt. It makes an extraordiary claim, and so needs extraordiary evidence.  Serendi <sup style="color:#bb0000;">pod ous  19:45, 26 March 2009 (UTC)
 * I think I finally understand our disagreement. To summarize, I found this image interesting for the same reason you object to it- it is 'different'. However, I put aside my personal judgment about the source to be objective, in the same way we must have some faith in any source (or scientific study for that matter) to include it. At the same time, if the LPI did not base this image on real research, they have done us both a great dis-service by wasting our time, and spreading unscientific images to the general public (the image can be found on other websites also). Fotaun (talk) 20:20, 26 March 2009 (UTC)

[outdent] Well, just to be clear, I would be perfectly happy to include that picture, if a scientific paper explaining this alternate hypothesis could be found. Right now the only evidence this picture presents for its hypothesis is itself. I don't know if the information presented in that image is "unscientific", though it is almost certainly outdated.  Serendi <sup style="color:#bb0000;">pod ous  20:44, 26 March 2009 (UTC)

Does anyone have a link to the full "Subsurface oceans and deep interiors of medium-sized outer planet satellites and large trans-neptunian objects" article. Fotaun (talk) 22:22, 24 March 2009 (UTC)

No Editing?
why cant we edit this page contains controversial topics and should allow insight from users

i had something i wanted to say and i cant —Preceding unsigned comment added by Spyguysaac (talk • contribs) 15:30, 18 May 2009 (UTC)
 * It is only semi-protected. I think this means any registered user can edit it. So with your new username you should be able to edit now. HumphreyW (talk) 15:35, 18 May 2009 (UTC)
 * You need to have been editing for four days first, so Wikipedia knows it can trust you. This page, like you said, is controversial, so it gets a lot of edits from very angry people who just want to vent, and needs to be screened. What is it you wanted to say? If you tell me I can add it for you. BTW, please sign your posts with 4 ~ marks. Thx.  Serendi <sup style="color:#bb0000;">pod ous  15:37, 18 May 2009 (UTC)

Omg! Why can't we edit? I still think Pluto is a planet and now my voice is being stifled. I am a legitimate scientist, I got my degree at Concordia University in Montreal. They only protected the article so that they could better censor the TRUTH. —Preceding unsigned comment added by 24.201.11.29 (talk) 21:31, 3 November 2009 (UTC)
 * Register and then edit unlocked pages for four days, and you can edit here.  Serendi <sup style="color:#bb0000;">pod ous  21:35, 3 November 2009 (UTC)
 * As Serendipodous said, register and edit away. Just please remember to provide a reliable reference for controversial edits. -- Kheider (talk) 23:00, 3 November 2009 (UTC)
 * I wasn't aware that legitimate scientists began requests to edit with "OMG"... but I did note that the IP's second edit was this one. --Ckatz <sup style="color:green;">chat <sub style="color:red;">spy  01:03, 4 November 2009 (UTC)

Requested move
Pluto → Pluto (dwarf planet) &mdash; There are numerous items of interest with the name Pluto, most notably the Roman God and the Disney character. I don't see any reason for this to be the automatically directed article, now that it is no longer in the news. Thus "Pluto" should redirect to the disambiguation page, and this should be a separate page.

According to wikipedia conventions:


 * "Disambiguation is required whenever, for a given word or phrase on which a reader might use the "Go button", there is more than one Wikipedia article to which that word or phrase might be expected to lead."


 * "If there are three or more topics associated with the same term, then a disambiguation page should normally be created for that term"

I think both are clearly the case for "Pluto". I also can not see how it can be defined as the primary topic when it gets about 4,000 hits a day, compared to 400 for the Disney character and 300 for the Roman God, 200 for the manga, 600 for Sailor Pluto and around 70 for several other topics on the disambiguation page. Thus probably 40-50% of Pluto hits are not for this article, and that's considering this page gets a lot of hit for being the one that comes up when you type in Pluto! Additionally, the first five pages of Google results, for both web and image searches, come up with all sorts.

The Enlightened (talk) 10:28, 11 August 2009 (UTC)


 * I'm afraid that I can't be bothered to find the archives of the various discussions that we've already had on this topic. Suffice it to say that it had already been discussed multiple times, and every discussion has led to a consensus that the page should remain at its current title Pluto.  Bluap (talk) 13:05, 11 August 2009 (UTC)


 * Er, you can't see how it can be defined as the main topic when it gets seven times as much traffic as the next down the list? Given also that Sailor Pluto seems more popular than Mickey's dog, I don't really see which subtopics are currently so notable as to cause confusion.  Serendi <sup style="color:#bb0000;">pod ous  13:12, 11 August 2009 (UTC)


 * Strong oppose. &mdash; CIS (talk | stalk) 03:52, 12 August 2009 (UTC)
 * Oppose. The planet dwarf planet is a way more common search target than any of the others. Jafeluv (talk) 06:50, 12 August 2009 (UTC)
 * Oppose. At this point, this isn't even worth discussing. Sorry. — V = I * R  (talk) 07:05, 12 August 2009 (UTC)
 * Oppose. It was the most obvious choice even before it stopped being news. Peter Isotalo 10:39, 12 August 2009 (UTC)
 * 400+300+200+600+70 = 1570 non-dwarf-planet hits. Proportion non-dwarf-planet hits = (non-dwarfplanet hits)/(total number of hits) = 1570/(4000+1570) = 0.28.  Talk of "probably 40-50%" hits being for non-dwarf-planet topics is just wrong.  70% of hits being for this topic is a pretty good indication of WP:PRIMARYTOPIC status.  Oppose. Knepflerle (talk) 11:09, 12 August 2009 (UTC)
 * This has indeed been discussed before - see the article header. The archive of the last discussion for this exact move is at Talk:Pluto/Archive_9. --Stephan Schulz (talk) 11:28, 12 August 2009 (UTC)

equatorial surface gravity ?
I was wondering if the estimated gravity on pluto is correct here on the wiki page, as far as i know you caculate the gravitation like this : g = g*M/r^2 and by using the data for pluto for this equation i seem to get 0.66 m/s^2 what have i done wrong ? —Preceding unsigned comment added by Borupdk (talk • contribs) 07:17, 4 September 2009 (UTC)
 * I changed to the correct value. You seems to have found an error on the NASA page for Pluto. Ruslik_ Zero 07:44, 4 September 2009 (UTC)
 * Please do not change from a sourced to a self-computed value. If you do anyways, please do remove the attribution to the given source! I've looked over the web, and there are widely varying numbers out. NASA's "Pluto fact sheet" at has 0.58 m/s2. I've found values from 0.4 to 0.81 (our current source, also NASA ). We should probably pick up all the data from one source, and preferably one that is consistent. German Wikipedia uses the NASA Pluto fact sheet, and that looks good to me. --Stephan Schulz (talk) 09:04, 4 September 2009 (UTC)
 * I always self-compute such values. There is no need to reproduce obvious errors. Ruslik_ Zero 10:35, 4 September 2009 (UTC)
 * Then you violate WP:OR. How do you know that of the three values diameter, mass, surface gravity the surface gravity is wrong, not one (or both) of the others? The solution is not to compute these values (from uncertain assumptions), but to find a better source. --Stephan Schulz (talk) 11:16, 4 September 2009 (UTC)
 * This is (if you do not know) called routing routine calculations. How do I know that the mass and radius are not wrong? It is because I read reliable sources, not strange fact sheets of dubious quality. The ref 4 contains all necessary information for calculation of g. Ruslik_ Zero 11:51, 4 September 2009 (UTC)
 * I got rid of NASA fact sheet. Ruslik_ Zero 12:11, 4 September 2009 (UTC)
 * (ec) Ref. 4 also contains the inconsistent value for surface gravity. Why do you think it's reliable for one, but not the other? The "strange fact sheet of dubious quality" is from NASA's National Space Science Data Center, while ref 4 (the Solar System Exploration site) is a PopSci outreach program. A priori I would assume that both NASA sites are reliable, but if one is internally inconsistent, and the other one is a) consistent and b) a dedicated science data repository, I'd go with the later. --Stephan Schulz (talk) 12:12, 4 September 2009 (UTC)
 * I meant the article of Buie et al, which now (after I removed the NASA fact sheet) is ref 2. Ruslik_ Zero 12:44, 4 September 2009 (UTC)

Venitia Burney misspelled
The caption for her picture in Pluto - Name 1.1 reads "VenItia Burney" everywhere else it is VenEtia Burney, which agrees with Google.


 * ✅ Quite right! I corrected it here, thanks! ~ Amory <font color="#555555"> (user • talk • contribs) 23:42, 19 September 2009 (UTC)

About the main image and infobox..
I don't think it's very good, the pixels are huge and it looks more like a disco ball than a planetoid and the neon green is wrong, it's just wrong. I hope you'll agree and I offer three different alternatives, an explanation of their origin can be found on their pages and note that they are all proximately the same age as or newer than the current image. I think  this color  is good for the heading bars with these images (it'll appear darker in the bars). It's too bad we can't have pictures taken of Pluto at different points in its orbit: I′d※<3※Ɵɲɛ (talk) 01:08, 22 October 2009 (UTC)

These images look nice. I do have some notes and questions:
 * The resolution seems to be about the same as the current image (just a blurring technique instead of pixelation)
 * This is a featured article: Can we verify the source and/or that these images are Fair use?
 * I doubt these are true color. It is likely a simulated color generated by a computer program.

I also suspect the image File:PlutoColorMap HST2002-2003.jpg is a simulated color. -- Kheider (talk) 03:41, 22 October 2009 (UTC)

Yes, I'm sure a close-up picture of Pluto will be much different than these (I suspect the orange is clouds and maybe the blue is Pluto's surface, notice that the older picture which was taken when Pluto was closer to the Sun seems to have more orange). They're screenshots of a graphic that was made/taken by the Hubble, so it should be fair to use. These are parts of the documentary that I got the shots from (approx. 6:19; 3:44 of the second proves that the image was made with the Hubble), sadly I can't find credits. --I′d※&lt;3※Ɵɲɛ (talk) 04:02, 22 October 2009 (UTC) I credited the creator(s?) on the Commons versions as best I could, not positive I spelled the name correctly. --I′d※&lt;3※Ɵɲɛ (talk) 04:41, 22 October 2009 (UTC)


 * I seriously doubt that little Pluto has clouds that can be seen by Hubble. Even clouds on larger Triton were hard to see with the Voyager spacecraft. Around 2:10 into the 1st video they mention nothing about visible clouds. Around 5:15 they mention Pluto behaving like a comet. :) -- Kheider (talk) 05:07, 22 October 2009 (UTC)


 * The images are the work of Marc W. Buie. I suspect that they only qualify for "Fair Use" on the English Wikipedia and will probably have to be removed for commons due to copyright issues. -- Kheider (talk) 05:07, 22 October 2009 (UTC)

But Pluto is only just now coming out of perihelion, it has been closer to the Sun than Triton for more than a decade, so it's surface has probably been heated a bit more than Triton which could've caused some of Pluto's methane ice to melt more than Triton's is what I was thinking, but since this was "created" who knows. Venus is also comet-like from what I understand. At any rate I've corrected the spelling of his name on the Commons versions for whatever that's worth and I'll correct it on the Wikipedian. --I′d※&lt;3※Ɵɲɛ (talk) 05:39, 22 October 2009 (UTC)

As regards fair use, we can't really argue it for not swapping the current picture out, as the current picture is justified under fair use as well. It is kept here because it is, as far as we know, the best picture of Pluto yet taken. If the picture above is fair use, then I would say leave the current picture be, as that picture is not an accurate representation. If we must use a free image, I would prefer this one to that. Serendi <sup style="color:#bb0000;">pod ous  07:20, 22 October 2009 (UTC)
 * That pic is basically just a b/w version of the ones to the right. None of them show much detail or definition and all are fuzzy, the Hubble pretty much had to squint to take these, but this is apparently a quote "true color image," so I think it's more informative. --I′d※&lt;3※Ɵɲɛ (talk) 15:57, 22 October 2009 (UTC)
 * I seriously doubt that those pictures are true colour. Pluto is very bright, about as bright as day-old snow. Such dark pictures are misleading at best. Serendi <sup style="color:#bb0000;">pod ous  16:42, 22 October 2009 (UTC)

I'm fairly sure the scientific consensus is that the color variations are surface features. Also, I believe the green headers are standardized for icy objects by the relevant WikiProject. If it came to a vote, I prefer the current image, in my opinion the pixellation shows more accurately the level of resolution. The blurred ones just seem less realistic to me. --Patteroast (talk) 16:26, 22 October 2009 (UTC)


 * I e-mailed Marc. According to Marc, this is a preliminary result from 2005 and the final results are being readied for publication in the Astronomical Journal. We may want to wait for the final product.  I am somewhat concerned that others will also see "clouds" where there are none visible at this resolution. -- Kheider (talk) 17:16, 22 October 2009 (UTC)


 * Pluto is the only "dwarf planet"/KBO article I've seen with this green color. Well I was only saying I was wondering that, Pluto afterall is now moving away from the Sun, so if it DID have clouds it would be now and over the last decade and a half since from what I understand they would be made of sublimated methane from Pluto's temporarily warmed surface (that comet thing again), but we won't really know until New Horizons reaches it, and that'll only last a day.


 * I get how they could seem less real, like someone just painted them in an imager or something, but if they truly are Pluto as it appears from what we can see than it is what it is. I think it's slightly better magnification than the currently used one, which to me looks like it was taken in small zoom and just stretched, which prevented it from getting the contrasted colors of the images I added, but I definitely understand the objections. --I′d※&lt;3※Ɵɲɛ (talk) 17:48, 22 October 2009 (UTC)

Since these images are not yet published, it is difficult to properly interrupt them, ie the possible assumptions of visible clouds, volcanoes, and vegetation. Until the final product is published, we may want to hold off on using it. The good news is that the final product is of a higher resolution. But perhaps others will want to use the preliminary version. -- Kheider (talk) 18:07, 22 October 2009 (UTC)
 * I agree, I think the main picture should bechange ASAP. It dosen't even slightly resemble Pluto. I thought Pluto was made of Rock and Ice, So shouldn't it be Blue and Grey? Not White like the Current picture shows it?! —Preceding unsigned comment added by Austinrok1919 (talk • contribs) 02:11, 17 December 2009 (UTC)
 * Part of the problem is that we simply do not know what Pluto truly looks like. No telescope has ever resolved it at a high enough resolution.  The surface of Pluto may be partially covered in tholins since it does not have a thick enough atmosphere to fully protect the surface from irradiation. -- Kheider (talk) 07:39, 17 December 2009 (UTC)


 * New Pluto pics at Hubblesite.org - get to it folks! :) - Gobeirne (talk) 22:56, 4 February 2010 (UTC)

So is pluto a planet in some jurisdictions?
So it seems Pluto is considered a planet legally in California, New Mexico, and Illinois among other jurisdictions in the US alone. Are there any other locations where Pluto is considered a planet as well? Gateman1997 (talk) 05:15, 12 November 2009 (UTC)
 * What do you mean by "considered a planet legally ..."? Are you suggesting that it is illegal to call Pluto something other than a planet? HumphreyW (talk) 07:49, 12 November 2009 (UTC)
 * The USA is just one country and does not own the global conscious. What you call or do to inflatable Pluto's in your bedroom is your own business. :) -- Kheider (talk) 16:14, 12 November 2009 (UTC)
 * Not saying it's illegal, but at least 3 US states have passed resolutions stating that Pluto is a planet in their borders. I'm just wondering if they're alone or if other jurisdictions have done the same. If there's enough of them it might be cause for an addition to the article. Gateman1997 (talk) 17:24, 12 November 2009 (UTC)
 * States' laws have nothing to do with science. Science operates according to a strict set of stringent shared definitions that have next to nothing to do with the outside world. It has to; different people need to be able to read others' papers and understand exactly what they're referring to, otherwise experiments can't be repeated and science can't work. The International Botanical Congress has an official definition of "berry" that includes avocados, bananas and peaches but excludes raspberries, strawberries and blackberries. But I have yet to hear of "Save the strawberry" protests. Serendi <sup style="color:#bb0000;">pod ous  17:42, 12 November 2009 (UTC)
 * If that's the case then the 4% of astronomers argument would be even stronger. Doesn't seem like it is a shared definition yet. Just one that 4% of astronomers foisted on the other 96%. To say nothing of the rest of the scientific community and general public. And it's a definition that has been considered laughable by many within even the community of astronomers. Gateman1997 (talk) 17:47, 12 November 2009 (UTC)
 * The whole "4 percent" thing is really a red herring. The IAU is the body assigned with arriving at astronomical definitions. That's its job. Just because only 4 percent of astronomers were there at the meeting doesn't mean that a) the other 96 percent disagree, b) that their opinions supercede the IAU (the MPAA represents a microscopic percentage of the film industry, but that doesn't mean I can take a ten year old to see Showgirls) or c) there's anything they could do about it if they did. All this talk about the IAU's authority being undermined or of planetary scientists forming their own congress is just Alan Stern venting. He's got a Pluto mission to cheer on, so of course he's upset, but I guarantee you he's still going to submit the names for any new features discovered on Pluto to the IAU.  Serendi <sup style="color:#bb0000;">pod ous  17:52, 12 November 2009 (UTC)
 * To coin a definition that strips off planetary status from Earth and Jupiter among the others is much worse, it's total compromitation. That's why they had to append a list of the planets by name at the end of it. GrzegorzWu (talk) 09:49, 13 November 2009 (UTC)
 * No. No no no no no. The IAU's definition in no way strips Earth or Jupiter of it's 'planet-hood'. On the contrary, the definition clearly includes them. The requirement for 'clearing the neighborhood' means that any objects near a planets orbit must either be A) of insignificant mass to the planet and in an unstable orbit or B) completely gravitationally dominated by the planet. The near Earth asteroids taken together are a mere speck compared to Earth, and almost all destined to eventually impact Earth or be pushed into different orbits... and the Trojan asteroids are in narrowly defined areas where they are kept by the influence of Jupiter. This line of argument is simply incorrect. --Patteroast (talk) 00:12, 14 November 2009 (UTC)
 * This is getting dangerously off-topic. We should be focusing on the article. If there is anything the OP feels the article currently lacks, please let me know.  Serendi <sup style="color:#bb0000;">pod ous  01:37, 14 November 2009 (UTC)
 * Actually, you CAN take a 10-year-old to see "Showtunes". The MPAA is in no way legally binding and is a private group. 75.118.170.35 (talk) 19:35, 14 December 2009 (UTC)
 * In the United States, Showgirls was taken back to the editing room to be recut for an R rating. -- Kheider (talk) 22:10, 14 December 2009 (UTC)

Grammar Fix
On the second paragraph, the following should be changed:

This causes Pluto periodically to come closer to the Sun than Neptune.

changed to:

This causes Pluto to periodically come closer to the Sun than Neptune.

or

This causes Pluto (periodically) to come closer to the Sun than Neptune.

I think even the last suggestion should have 'periodically' come after 'to'.
 * See split infinitive. Someone obviously cared. Don't really give a toss myself, but I won't begrudge anyone their idiosyncrasies.  Serendi <sup style="color:#bb0000;">pod ous  02:25, 13 December 2009 (UTC)


 * Fixed, or changed back. "periodically to come" isn't normal English. kwami (talk) 22:21, 31 December 2009 (UTC)

Broken Reference
The following citation links to a broken page:

^ "New Horizons, Not Quite to Jupiter, Makes First Pluto Sighting". The John Hopkins University Applied Physics Laboratory. 2006-11-28. http://pluto.jhuapl.edu/news_center/news/112806.htm. Retrieved 2007-03-20

Anyone know if this article still exists somewhere? —Preceding unsigned comment added by 74.47.145.4 (talk) 11:20, 25 December 2009 (UTC)


 * The article is at http://pluto.jhuapl.edu/news_center/news/112806.php and I've corrected the links in both Pluto and New Horizons.---Glenn L (talk) 01:41, 26 December 2009 (UTC)

New Horizons is now halfway to Pluto
This site: [Fox] writes that New Horizons is now halfway to Pluto.Agre22 (talk) 21:18, 31 December 2009 (UTC)agre22

Name/nomenclature
There are two sections giving completely contradictory origins for the name Pluto (the 11-year-old girl picked it based on the mythological Hades alernate name, and the other origin says it was meant to nvokew the intials PL.  Which is it???  THe second one sounds made up, so I'm removing it. 162.136.193.1 (talk) 21:55, 5 January 2010 (UTC)
 * The name was suggested by the girl, but was chosen by the Observatory partially due to the "P-L" coincidence.  Serendi <sup style="color:#bb0000;">pod ous  21:58, 5 January 2010 (UTC)

Status as planet
The summary at the top of the page incorrectly identifies Pluto as the largest object in the Kuiper belt, Eris is in fact larger


 * Eris is indeed larger, but it is not part of the Kuiper Belt. Eris is a member of the Scattered Disc. HumphreyW (talk) 15:53, 19 March 2010 (UTC)

I just came across some information that was new to me, and I thought I would share it here in case some of the editors who helped Pluto reach featured status thought it merited inclusion. Apparently, within a month of discovery of Pluto, there were questions as to its status as a planet. For two examples near Pluto's discovery, see this news item and journal article, as well as the more current review. Now, there are a couple of sentences already in the article saying "Once found, Pluto's faintness and lack of a resolvable disc cast doubt on the idea that it could be Lowell's Planet X. Estimates of Pluto's mass were revised downward throughout the 20th century." That is a bit weak though, and leaves out what seems like an interesting story of how it came to be accepted as a planet in the first place, and the fact that even in 1930 there were astronomers speculating about the possibilities that Pluto was just one of many trans-Neptunian objects. James McBride (talk) 10:17, 17 January 2010 (UTC)
 * Those are some excellent sources, and they could be incorporated into the article on Pluto's discovery, Planets beyond Neptune.  Serendi <sup style="color:#bb0000;">pod ous  11:00, 18 January 2010 (UTC)

See image discussion at

 * Talk:Pluto/Archive 11
 * New Pluto pics at Hubblesite.org - get to it folks! :) - Gobeirne (talk) 22:56, 4 February 2010 (UTC)
 * Is this image really in false colors ? It is said at Hubblesite: "Hubble's view isn't sharp enough to see craters or mountains, if they exist on the surface, but Hubble reveals a complex-looking and variegated world with white, dark-orange, and charcoal-black terrain. The overall color is believed to be a result of ultraviolet radiation from the distant Sun breaking up methane that is present on Pluto's surface, leaving behind a dark, molasses-colored, carbon-rich residue." Cochonfou (talk) 06:49, 5 February 2010 (UTC)

The Pluto image gallery needs to be made into a thumbnail. Right now it's too obstructive.  Serendi <sup style="color:#bb0000;">pod ous  09:17, 5 February 2010 (UTC)
 * You could try File:Pluto-map-hs-2010-06-a-faces.jpg -- Kheider (talk) 09:49, 5 February 2010 (UTC)
 * I still think that image is too dark. Could that object really have a 50%+ albedo?  Serendi <sup style="color:#bb0000;">pod ous  14:10, 5 February 2010 (UTC)
 * Pluto might be what you would get if you put Callisto (albedo 22%) and Rhea (albedo 94%) into a blender. -- Kheider (talk) 19:38, 5 February 2010 (UTC)
 * It's possible that the darkness of the image may be viewed as a representation of the object's distance from the Sun, rather than a reflection (so to speak) of its albedo. Perhaps it might be illustrative within the article to describe how luminous Pluto would appear from the surface of Charon, and compare that to the brightness of the Moon as seen from the Earth. Such a value might be difficult to cite though.&mdash;RJH (talk) 22:37, 6 February 2010 (UTC)
 * I added a reasonable amount of discussion to the Appearance and surface section. Iridia (talk) 11:56, 10 February 2010 (UTC)

Physical characteristics of Pluto
Any opinion on moving the big Physical characteristics of Pluto into its own article?? Any objections?? Georgia guy (talk) 16:25, 19 February 2010 (UTC)
 * The article is long, but it's not really any longer than the other planetary articles. Eventually, when the New Horizons probe gets to Pluto, this article is going to be massively expanded, and when that happens, subsections will have to be split off, but not now.  Serendi <sup style="color:#bb0000;">pod ous  16:30, 19 February 2010 (UTC)
 * I second Serendipodous's opinion. Besides there is still a lot of debate about Pluto as a planet, and I do not think "Joe Q. Public" reads sub-articles too often. -- Kheider (talk) 18:20, 19 February 2010 (UTC)
 * they misquoted the article in giving the radius of pluto. But also a few paragraphs before stating the radius of the core being 1700km, which is larger than Pluto's approximate radius of 1145km.  I don't have access to this article but this value is obvious in contradiction. Tiasusnmt (talk) 04:04, 9 March 2010 (UTC)

1905/1906?
Reference #16 (Space.com 2005) of the article on Pluto, states: 'Lowell Observatory's search for a ninth planet was begun by founder Percival Lowell in 1905.'

While in Wikipedia's article states the year 1906:

'In 1906, Percival Lowell, a wealthy Bostonian who had founded the Lowell Observatory in Flagstaff, Arizona in 1894, started an extensive project in search of a possible ninth planet, which he termed "Planet X".[16]'

The Wikipedia article is therefore incorrect. Please edit the Wikipedia article to reflect the necessary and correct change. (i.e. 1906 to 1905) —Preceding unsigned comment added by 98.202.193.61 (talk) 20:54, 21 February 2010 (UTC)
 * Clyde Tombaugh's account says 1906. I'm not sure which source to trust here.  Serendi <sup style="color:#bb0000;">pod ous  21:09, 21 February 2010 (UTC)
 * True, but he does bring up a good point, the article does not reflect what the reference says the date was. I would agree with the change to 1905 unless a better source showing that the observation campaign did begin in 1906 can be found.  --Volcanopele (talk) 02:10, 22 February 2010 (UTC)
 * Percival Lowell (start class article) does suggest 1905. -- Kheider (talk) 02:32, 22 February 2010 (UTC)
 * Then 1905 appears correct.  -RadicalOne •Contact Me•Chase My Tail 02:34, 22 February 2010 (UTC)
 * Clyde Tombaugh's own peer-reviewed account of his search program might be more authoritative than a Space.com article. See the first page of |this, which says 1906. Iridia (talk) 03:11, 22 February 2010 (UTC)
 * Okay that's what I was waiting for. I've gone ahead and switched the date back, and added the new reference.  --Volcanopele (talk) 03:24, 22 February 2010 (UTC)
 * That's a good find Iridia. I always wondered what size telescope(s) Lowell had used. Now I know that Lowell started a search program in 1906 using a camera 5 inches in aperture and that from 1914 to 1916, a 9-inch telescope was used. -- Kheider (talk) 04:01, 22 February 2010 (UTC)
 * It is rather fun reading how it was done. I was looking at that article a few weeks back, so it was easy to pull out again. Iridia (talk) 04:11, 22 February 2010 (UTC)

According to Leuschner (1932 top of page 198), "Preliminary observational tests began as early as 1905." So I don't think there is a perfect answer. -- Kheider (talk) 04:47, 22 February 2010 (UTC)

colour
pluto is a mixture of brown black and a dark gold —Preceding unsigned comment added by 119.12.225.141 (talk) 06:32, 2 March 2010 (UTC)

Merge with Atmosphere of Pluto
This article hasn't been substantially expanded in months, and, I think, has only served to keep important information, such as Pluto's atmospheric temperature and pressure, off the main page. In time, (5 years in fact) we will have enough data to justify a separate article, maybe. But we don't now, and that information needs to be on here.  Serendi <sup style="color:#bb0000;">pod ous  17:35, 4 March 2010 (UTC)
 * Support - Currently the Atmosphere on Pluto article is just a copy of the information in the Pluto article, plus information that should be in the main article, like temperature and pressure. I don't think there is enough information at present to do an expansion of Atmosphere of Pluto to justify it at the moment.  --Volcanopele (talk) 04:34, 7 March 2010 (UTC)
 * I went ahead and did it. There are some sourcing problems with the additional information, but I'll deal with those later.  Serendi <sup style="color:#bb0000;">pod ous  10:20, 8 March 2010 (UTC)
 * Aaannd... Headbomb recreated it. Strange, since after the merge it has even less reason to exist than it did before. Still, I'm sick of edit wars, so I'll let this one go.  Serendi <sup style="color:#bb0000;">pod ous  15:22, 8 March 2010 (UTC)
 * Support. The nice piece of space art that is the main illustration for the Atmosphere article is currently under nomination for deletion due to copyright breach, as well. Though - with Pluto going through the galactic plane, there might be a few more occultations on the way, and more atmospheric data, before 2015. Iridia (talk) 01:04, 9 March 2010 (UTC)
 * I didn't see this thread requesting for a merge, so apologies for undoing your edit. I've reverted myself. Headbomb {talk / contribs / physics / books} 01:56, 9 March 2010 (UTC)

OK; I think I found a source for the unsourced material. But I'm having trouble understanding it. It seems to be saying that methane is responsible for the temperature inversion in Pluto's atmosphere, but also that there is more methane at the surface, which seems paradoxical, since methane would make the lower atmosphere warmer, right?  Serendi <sup style="color:#bb0000;">pod ous  17:02, 1 April 2010 (UTC)
 * Methane heats the lower atmosphere due to greenhouse effect, but it also heats the upper atmosphere because it is a good absorber of Solar UV radiation. In between there is a minimum of temperature. So we have the temperature inversion. Ruslik_ Zero 19:35, 1 April 2010 (UTC)

Other stuff in Pluto's orbital trajectory
As it is currently written, the beginning of the article fails to mention the REASON Pluto is no longer considered a planet, which is, there is too much other stuff in the orbit. In order to qualify as a planet, you have to have absorbed and assimilated all the other mass in your orbit besides yourself; Pluto has not, there's lots of other rocks and ice in it's orbital trajectory.

Should be changed to mention this early in the article. —Preceding unsigned comment added by 207.237.243.185 (talk) 04:17, 11 March 2010 (UTC)


 * Actually to be a planet you only need to dominate your region. Obviously you will not accrete all of your moons or nearby asteroids/comets.  You only need to be capable of scattering temporary interlopers that enter your region.  Pluto happens to have almost exactly the same semi-major axis (average distance from the Sun) as dwarf planet candidate 38628 Huya.  They both have a 2010 Epoch with an average distance from the Sun of 39.44AU and are both dominated/controlled by Neptune.  The 2nd sentence of the lead does mention that "Pluto is now considered the largest member of a distinct population called the Kuiper belt." -- Kheider (talk) 17:00, 11 March 2010 (UTC)

"Pluto protesters?"
The pictures of "Pluto protesters" shown in the article need more explanation because they give a completely false impression of what actually happened in 2006. The so called "protest" is actually a satirical annual event intended to promote a non-profit organization called 826 Seattle. This organization helps children with creating writing. It has an office called the "Greenwood Space Travel Supply Company" in Seattle's Greenwood neighborhood where I live. Please update the article to show that the event is intended to be satire.

This blog entry helps explain that the event is not really intended to be taken seriously as a protest: http://www.phinneywood.com/2010/03/08/pluto-protest-at-greenwood-space-travel-saturday/ --Rondo66 (talk) 11:36, 25 March 2010 (UTC)

Pluto Concept
I'd like to add an image of the Pluto system to this page since it lacks one and obviously no real ones will be available for several years. The first attempt is the file Pluto for wiki.jpg

This is broadly in line with other professionally created simulations see for example File:Pluto concept.jpg

Some users have raised objections to the look of the image so I would like to have a discussion here to modify the image to achieve a broad consensus. I would especially welcome input from those with actual knowledge in the area.

One objection is the ring. I agree we have no idea if it will have one or not though the article text states the possibility so we should be consistent between image and text.

Timwether (talk) 23:25, 17 May 2010 (UTC)


 * The image is good, but artist impressions are always a touchy subject on Wikipedia simply because they can easily be misleading. I think the rings would have to go simply because they are "unknown".  I suspect that you put Nix and Hydra on the inside part of their orbits so that they would be more visible, but this will also give the lay person the impression that they orbit inside of Charon. -- Kheider (talk) 00:47, 18 May 2010 (UTC)
 * What frustrates me is I don't know which picture is more correct, the one at the top or that one. Pluto is supposed to have the most contrasting surface in the Solar System after Iapetus, but also an albedo as bright as dirty snow. So which is it?  Serendi <sup style="color:#bb0000;">pod ous  05:34, 18 May 2010 (UTC)
 * There's already an artist's impression of the system down in Atmosphere. The image at the top of the article is as good as it's going to look until New Horizons arrives, and that image is at comparable resolution to that which we see on the full Moon. Timwether, if you wish to refine your image, I would suggest contacting Marc Buie directly and asking him for comment. Iridia (talk) 05:51, 18 May 2010 (UTC)

Thank you for the input. Yes perhaps the ring should go it is purely speculative. I’ve created a revised image in the commons moving Nix and hydra to better represent their placement (within the confinement of a reasonably condensed picture). I’ve also increased the contrast. This is a tricky subject locally because the planetary scientist I created this image with feels that the contrast would be rather less that the Hubble map suggests for various reasons that are rather too extensive to go into. As you suggest, I’ll see if Marc Buie would mind giving some input too.

The question of having a “conceptualization” in the Pluto article at all is a very valid one and I have no particular axe to grind on it. I’m a professional scientist mostly retired from research now and run an educational magazine for one of the major Australian Universities. Wiki is very valuable to me so when I create images for the magazine that I feel may be of value, I like to post them to give something back. If the consensus is that a simulation would add to the article I’ll happily make this one as good as it can be, if not that’s fine too.

What I find in my outreach work is that a nice exciting image can often stimulate the imagination of youngsters - though clearly we wouldn’t wish to convey false impressions in the process.

Timwether (talk) 05:21, 19 May 2010 (UTC)
 * Hi Tim. I thought you would be glad to know your revised image is being used for Hydra (moon). -- Kheider (talk) 16:35, 24 May 2010 (UTC)

A number of scientists continue to hold that Pluto should be classified as a planet
I think this part should be removed (but I didn't want to mess up the formatting/have a orphan footnote). The quoted scientists in the article seem to be disagreeing with the name 'plutoids' and preferring 'dwarf planet'. Does not represent a current view that pluto should be a planet rather than a dwarf planet. Jimbowley (talk) 11:01, 19 June 2010 (UTC)


 * I assume that the plutoid/DP mixup was a misunderstanding of the reporter. You can't expect a newspaper to get anything technical right.
 * My objection to it is that it reports on what "will" happen in 2008, whereas by now we should have some follow up. If this is all we have, I agree that it should be deleted. — kwami (talk) 11:13, 19 June 2010 (UTC)

"minor planet 2060 Chiron"?
Is that terminology correct? Shouldn't it be "the planetoid Chiron?" —Preceding unsigned comment added by 74.83.46.251 (talk) 05:20, 9 August 2010 (UTC)
 * Minor planet and planetoid mean the same thing; minor planet is the more academically accepted term.  Serendi <sup style="color:#bb0000;">pod ous  05:59, 9 August 2010 (UTC)

Astrological Symbol
Does anyone else feel like Pluto's astrological symbol does not really belong where it is in this article? Chaleur (talk) 20:26, 24 August 2010 (UTC)
 * Given that both its astronomical symbol and its astrological symbol are currently of equal use to astronomers, I see no reason why they shouldn't reside next to each other.  Serendi <sup style="color:#bb0000;">pod ous  20:35, 24 August 2010 (UTC)

Self-ref
I'm undoing Serendip's undo (summarized "This doesn't appear to have improved it") of my addition of and attendant minor rewording: Appearances can be deceiving, and this suggests they are unaware of WP:Self reference, -- and of the effect of selfref, which in this case is to remove the implicit claim that Wikipedia conventions are relevant once the article is copied onto a page that is not part of Wikipedia (but to effect such removal only when it is so copied). (This raises, however, a larger question that i take the time to address only now that it has already been forced onto this discussion page: Wikipedia observes conventions stated in the MoS (such as which year begins a century other than the 1st century -- whether CE or BCE -- or the name for the first decade of a century or the formatting of titles of written works other than pages or sections on Wikipedia); each reflects our consensus on what the accepted convention in that area is. I haven't examined the "convention" about Pluto, but whether or not it is a desirable convention for us to use, it amounts to OR to explain something that conforms to it as a WP convention. The basis for it should be investigated and explained on this discussion page, and it almost certainly should be reworded to refer instead to the most authoritative non-WP body that follows that convention. --Jerzy•t 10:05, 25 August 2010 (UTC)


 * I reverted back again. I think the malformed note #9 creates a worse problem than you are trying to solve. HumphreyW (talk) 10:20, 25 August 2010 (UTC)
 * Instead I would be happy to see the entire note removed, or in some way reworded to avoid the reference to Wikipedia. HumphreyW (talk) 10:27, 25 August 2010 (UTC)


 * Agree with Humphrey W re: malformed note. As regards the endlessly recycled issue of convention, in this case it is simply one of necessity. There is, at present, no agreed definition of the Kuiper belt. One astronomer's definition will be different from another astronomer's definition, and which definition you choose will determine whether Pluto is or is not its largest object. Some astronomers (like Mike Brown) say that Eris is the largest member of the Kuiper belt, because they include the scattered disc as part of the Kuiper belt. Others, like Alessandro Morbidelli, contest that the scattered disc is separate from the Kuiper belt and that Pluto is therefore the KB's largest member. The closest thing we have to an authority on the issue, the IAU's Minor Planet Center, divides the outer Solar System's minor planets into two populations: "trans-Neptunian objects" (by which it means the Kuiper belt as defined by Morbidelli et al.) and "scattered objects". "Scattered objects" in this context means not just the scattered disc but the Centaurs, a group of minor planets which lie within Neptune's orbit, and that no astronomer considers part of the Kuiper belt. The established convention therefore, was an attempt to find a happy medium between the authority of the MPC and the overwhelming astronomical consensus.  Serendi <sup style="color:#bb0000;">pod ous  10:29, 25 August 2010 (UTC)


 * To make matters more complicated for the laymen, I have overheard Mike Brown refer to centaurs as KBOs since that is where they originate from. Though he may have marketed it as such since it is easier to take the spectrum of a centaur 23AU from the Sun than 30+AU from the Sun. -- Kheider (talk) 17:16, 25 August 2010 (UTC)
 * Odd; he told me in an email on no uncertain terms that the centaurs weren't KBOs.  Serendi <sup style="color:#bb0000;">pod ous  17:29, 25 August 2010 (UTC)
 * I suspect he was trying to sensationalise his "record for the faintest spectrum of a Kuiper belt object". :) -- Kheider (talk) 17:33, 25 August 2010 (UTC)

Dead link for telegraph article
The 12th source no longer links to the telegraph article. The correct link is http://www.telegraph.co.uk/science/science-news/3349184/Pluto-should-get-back-planet-status-say-astronomers.html —Preceding unsigned comment added by 137.165.169.120 (talk) 17:46, 18 October 2010 (UTC)


 * ✅. -- Kheider (talk) 17:53, 18 October 2010 (UTC)

There are still 3 dead links. Newone (talk) 09:49, 7 March 2011 (UTC)

Size?
Is there a consensus on the exact size of Pluto? This article gives diameters of both 2306 and 2320km, while on recent web articles I've also seen 2342 and 2344 km diameter claims, and the error bars don't overlap (±20 resp. ±10km). (With Eris' size estimate reduced to "probably <2340km", it'd be interesting to know which is larger in size.)--Roentgenium111 (talk) 15:31, 10 November 2010 (UTC)


 * We don't really know the size of Pluto either. This is much like the old debate between the asteroids 2 Pallas and 4 Vesta.  Pallas was discovered first and Vesta was known to be more massive, but it was years before they were somewhat confident that Pallas was larger. And remember the preliminary result of Eris<2340 figure comes from small scopes using long exposures with poor timing resolution and larger than wanted error bars.  The Eris vs Pluto volume issue can not currently be solved, but Eris is still the more massive and dense body. -- Kheider (talk) 16:16, 10 November 2010 (UTC)

Clarity of Expression
In the second paragraph, Pluto is said to be "relatively small". Small compared to what? Certainly not other Kuiper belt objects. Shame the article has to be locked. Stivc (talk) 18:11, 10 November 2010 (UTC)
 * I see your point but the sentence does go on to compare Pluto to Earth's Moon, and I really don't think adding anything would make the sentence clearer.  Serendi <sup style="color:#bb0000;">pod ous  18:16, 10 November 2010 (UTC)
 * I wasn't suggesting anything should be added. I would suggest replacing `and is relatively small' with a period.  Removing vagueness would make the rest more clear.  I'm going out of my way to achieve a stylistic fix on a locked page-- is this a waste of time? Stivc (talk) 23:48, 10 November 2010 (UTC)
 * Only if you think so. Personally, I disagree that that information should be removed. But then, Wikipedia is built on consensus, so let's see what others think.  Serendi <sup style="color:#bb0000;">pod ous  08:22, 11 November 2010 (UTC)


 * I support the replacement suggest by Stivc. Vagueness is never a good thing. HumphreyW (talk) 02:39, 18 December 2010 (UTC)


 * As long as the comparison to Earth's moon is left in, I don't mind. Pluto is small compared to the moon and HUGE compared my desk. -- Kheider (talk) 02:48, 18 December 2010 (UTC)


 * Actually why even have the comparison at all, it is arbitrary. Within Pluto's own class of dwarf planets it might well be the largest, at the very least currently the second largest. HumphreyW (talk) 02:55, 18 December 2010 (UTC)


 * The moon is a good frame of reference for the common reader. Many people still do not known that Pluto IS smaller than our moon. -- Kheider (talk) 03:45, 18 December 2010 (UTC)

Pluto *may be* larger than Eris!
Many are now reporting that Pluto is infact larger than Eris.

Here is one article..

http://blogs.chron.com/sciguy/archives/2010/11/surprise_plutokilling_eris_is_actually_smaller_tha.html

Space.com also has a nice one as well. The article needs to be changed, as does the Eris one. —Preceding unsigned comment added by 67.187.252.143 (talk) 08:09, 11 November 2010 (UTC)
 * Results are currently too preliminary to draw any firm conclusion as yet. And anyway, Eris is demonstrably more massive than Pluto, however big it is.  Serendi <sup style="color:#bb0000;">pod ous  08:21, 11 November 2010 (UTC)
 * Pluto has been estimated to be as low as 2290 km. Bruno Sicardy was using 2340km for Pluto.  So if Eris is 2340ish, it could still be the larger body.  The numbers are to close with to large of an error bar to accurately call.  We need to wait for more official results.  See above Size section. -- Kheider (talk) 17:13, 11 November 2010 (UTC)

For God's sake!
This has gone way too far. So far we have a set of extremely preliminary results that haven't even seen the inside of a peer-reviewed journal, giving a diameter for Eris that may or may not be smaller than Pluto, for which we don't have a precise diameter either. Why are we rewriting these articles to suggest that Eris is smaller than Pluto, when we have no confirmed evidence that it is?  Serendi <sup style="color:#bb0000;">pod ous  17:56, 12 November 2010 (UTC)


 * Bruno Sicardy does seem to be the leader in TNO occultations There is enough data that the articles do need to adjust some. And as I said on my talk page, if we do not wiggle some, the anon-IPs will make major edits claiming things such as Pluto is at least 4 meters in diameter larger than Eris. -- Kheider (talk) 19:21, 12 November 2010 (UTC)

Edit request from VeganLoverOfScience, 17 November 2010
The wikipedia article indicates that Eris is larger than Pluto, but this has can under dispute in the past couple of weeks. In short, recent measurements suggesting the size of Eris is actually 1,454 miles in diameter, while the current accepted value for Pluto’s diameter is 1,456.5 miles, thus Pluto is arguably the largest dwarf planet.

Source:
 * http://www.scientificamerican.com/blog/post.cfm?id=is-pluto-the-biggest-dwarf-planet-a-2010-11-08
 * http://cosmiclog.msnbc.msn.com/_news/2010/11/07/5426255-plutos-rival-gets-downsized
 * http://blogs.discovermagazine.com/80beats/2010/11/08/new-bragging-rights-for-pluto-it-may-be-the-biggest-dwarf-planet/

VeganLoverOfScience (talk) 07:18, 17 November 2010 (UTC)


 * Eris is more massive than Pluto. The diameter (volume) debate is mentioned in note #9 and the bottom of the Pluto section. We have already discussed this twice in the Talk:Pluto and Talk:Pluto sections. -- Kheider (talk) 08:00, 17 November 2010 (UTC)

Mike Brown size estimate
Brown's meta-analysis puts both at ~ 1165 km (Pluto ± 25, Eris ± 15 km). I don't want to change anything, because of the other figs which depend on this, but would this be a reasonable figure for both articles, given that the more specific numbers don't agree all that well, and seem to have underestimated their errors? — kwami (talk) 05:48, 23 November 2010 (UTC)
 * I have added this to the main article to help explain that Eris and Pluto are the same diameter, but I am not sure this is something we want (or need) to add to the infobox. -- Kheider (talk) 13:23, 23 November 2010 (UTC)
 * No, I don't think we want the details there, but I thought it might be good to use Brown's estimate as our primary number. That is the latest figure we have, it includes the older data, and accounts for reliability of that data from someone who has some idea what he's talking about. — kwami (talk) 01:40, 24 November 2010 (UTC)
 * Or someone could replicate and add to both articles the figure, citing the error bars to the papers involved, and then we could say that the blog's meta-analysis suggests this number, with the error bars, which aren't currently mentioned in the article.
 * Then the completely-rumour Eris occultation number can be shown in its proper context. (The main problem with this whole kerfuffle on the two articles has been a drive to view numbers without error bars as meaningful, and preliminary unpublished results off announcements as citable.) Iridia (talk) 04:09, 24 November 2010 (UTC)
 * The only problem here is that Mike's error diagram is copyrighted by him so we can not legally upload it as creative commons without getting his specific permission in an e-mail. We can always add the error bars to the text (and infobox).  I have not added the error bars to the text yet simply because I have dumbed it down to the least common denominator for any reader. -- Kheider (talk) 12:42, 24 November 2010 (UTC)
 * Since his numbers rather felicitously turned out to be the same for the two planetoids, I think we could just use 1165±xx km, and mention that, within the margin of error, they are about the same size. — kwami (talk) 20:40, 24 November 2010 (UTC)

formatting error
For some reason, it looks like reference 9 cuts off and the following part of the description is left hanging off somewhere in the margin "belt, so Pluto becomes the largest Kuiper belt object." Does anybody else see this? I would fix it but I don't know what's wrong or how to unmake it. I'm on chrome/OSX. - DaoKaioshin (talk) 00:58, 4 December 2010 (UTC)
 * Note 9 looks good under Firefox. -- Kheider (talk) 02:34, 4 December 2010 (UTC)
 * The problem seems to be in Chrome, since Safari, Firefox and IE are all fine.  Serendi <sup style="color:#bb0000;">pod ous  08:29, 11 January 2011 (UTC)

Pluto artist's conception
This was composed as part of a presentation, but perhaps it could be of some use here?

http://commons.wikimedia.org/wiki/File:Pluto.jpg — Preceding unsigned comment added by C m handler (talk • contribs) 12:32, 15 December 2010 (UTC)
 * Nice, but we tend to stay away from artists' conceptions, especially since New Horizons is on its way.  Serendi <sup style="color:#bb0000;">pod ous  09:10, 11 January 2011 (UTC)

Edit request from 67.169.72.25, 11 January 2011
edit semi-protected

Please change The web page http://en.wikipedia.org/wiki/Pluto which shows Pluto's radius Physical characteristics Mean radius 1,153 ± 10 km[2] (0.18 Earths) 1161 km[3](solid) and also shows Radius estimates for Pluto: 2007 1161 km Young, Young, & Buie [3]

and also it states under: Mass and size Pluto's mass is 1.31×1022 kg, less than 0.24 percent that of the Earth,[71] while its diameter is 2,306 (+/- 20) km, or roughly 66% that of the Moon

The new estimate should be listed as shown below

"The radius of Pluto, according to NASA researcher Dr. David R. Williams, dave.williams@nasa.gov NSSDC, Mail Code 690.1 NASA Goddard Space Flight Center Greenbelt, MD 20771 is 1195 km according to the web page http://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html dated 17 November 2010                                  Pluto          Earth      Ratio (Pluto/Earth) Equatorial radius (km)	           1195           6378.1        0.187

which would make the diameter 2390 km

Also, the NASA web page http://www.jpl.nasa.gov/solar_system/planets/pluto_index.html states the following for Pluto's diameter

Diameter 2,390 km (1,485.08 miles) (not the 2330 km in diameter shown on the Wikipedia page)

67.169.72.25 (talk) 06:20, 11 January 2011 (UTC)


 * You might find this article interesting.  Serendi <sup style="color:#bb0000;">pod ous  08:25, 11 January 2011 (UTC)


 * Even though that NASA page was recently updated, we do not know when the diameter was last updated. the 2,390km figure is just one of MANY estimates in the last 20 years. Many estimates are smaller than 2,390km.  Results from mutual event data place Pluto's radius at R=1160 km.  Though I like David R. Williams NASA page, I also know from personal experience that it does not always have show the most recent research results. Besides with Alan Stern so emotionally involved with Pluto being a planet, it is remotely possible that NASA's website is biased in favor of the largest estimates. The exact diameter of Pluto is just a best guess at this time. -- Kheider (talk) 17:26, 11 January 2011 (UTC)

Not done: There doesn't appear to be consensus for this change. -Atmoz (talk) 17:33, 11 January 2011 (UTC)

Date of perihelion
Hi. I suggest that the perihelion date be mentioned within the infobox based on JPL Epoch 2454000.5 data (May 8, 1989). The parameter within the infobox however causes it to be displayed as "time of periastron". The message over the template noted that discussion was required. Thanks. ~ A H  1 (TCU) 18:52, 16 January 2011 (UTC)


 * The date of perihelion is an epoch dependent calculation. The important point is that osculating elements at some epoch are always an approximation to an object's orbit (i.e. an unperturbed conic orbit or a "two-body" orbit). The Pluto-Charon barycenter actually came to perihelion on 5 Sept 1989.(set Observer Location to @sun to place the observer at the center of the sun) The Pluto-center-point came to perihelion "1989-Sep-08 03:00 29.6555658977902 -0.0004811". Do we want to use the simple barycenter version or should we go all out with the more complicated Pluto-center-point version? Using the barycenter version it is easy to see when the Pluto-Charon systems deldot goes positive (moving away from the observer=Sun). If you use the Pluto-center-point, Charon pulls Pluto around like an asteroid making the deldot jump all around. Just for the record, Charon's perihelion on 4 Sept 1989 was closer than Pluto's on Sept 8th. :-) -- Kheider (talk) 19:10, 16 January 2011 (UTC)
 * K, at this point, don't you think you should put this in the article? :)  Serendi <sup style="color:#bb0000;">pod ous  19:14, 20 January 2011 (UTC)
 * Should we add something like this as a footnote after the barycenter date? "The discovery of Charon in 1978 allowed astronomers to accurately calculate the mass of the Plutonian system. But it did not indicate the two bodies' individual masses, which could only be estimated, until the discovery of Pluto's outer moons in late 2005. As a result, since Pluto came to perihelion in 1989, most Pluto perihelion date estimates are based on the Pluto–Charon barycentre. Charon came to perihelion on 1989-Sep-04. The Pluto–Charon barycenter came to perihelion on 1989-Sep-05. Pluto came to perihelion 1989-Sep-08." -- Kheider (talk) 00:17, 21 January 2011 (UTC)
 * Seems good to me.  Serendi <sup style="color:#bb0000;">pod ous  00:20, 21 January 2011 (UTC)

length
This article's getting really really long. I've been looking for a place to trim it and I'm thinking the heaviest subsection is "Classification". I think that section to be trimmed to 2-3 concise paragraphs and the rest moved to IAU definition of planet. Any takers?  Serendi <sup style="color:#bb0000;">pod ous  15:13, 21 January 2011 (UTC)
 * Given how controversial the whole "Is Pluto a planet" topic is, the Classification section does not look that long to me. -- Kheider (talk) 16:03, 21 January 2011 (UTC)


 * The article length is not an issue to me. There isn't anything there that should not be there. HumphreyW (talk) 04:46, 22 January 2011 (UTC)
 * The prose is acceptable at 40k, trimmed the code to 100k, which is so-so. Maybe some external links could go. Materialscientist (talk) 06:03, 22 January 2011 (UTC)