Talk:Planet/Archive 5

per the IAU
In case this gets into an edit war, I changed a line:


 * According to the IAU's current definitions, there are eight planets and five dwarf planets in the Solar System.

The problem is that there are not 5 DPs; as we state further down, 5 is the number that have been accepted by the IAU. Since we aren't discussing DPs here, I simply removed the incorrect phrase:


 * According to the IAU's current definitions, there are eight planets in the Solar System.

Kheider thought this would be confusing to our readers, so he added it back in with the correction "recognized":


 * According to the IAU's current definitions, there are eight planets and five recognized dwarf planets in the Solar System.

This is better, but there are not 5 recognized DPs according to IAU definitions, as there are 8 planets according to their definitions. The IAU expects there to be many more DPs (according to their definitions, and actually everyone's definitions). Therefore I removed the word "definitions":


 * According to the IAU, there are eight planets and five recognized dwarf planets in the Solar System.

There are other ways we could word this and remain factually correct, if people find this unacceptable, though they tend to be a bit more awkward. Perhaps,


 * According to the IAU's current definitions there are eight planets in the Solar System; there are also five dwarf planets recognized by the IAU.

— kwami (talk) 12:21, 17 January 2012 (UTC)

In the lead paragraph, International Astronomical Union is written. Then IAU is written. A reader needs to work out that these things are the same. Reading the above debate, seems the correct word is not "recognised", but "known". And the words "According to", should be "Following..." or "Based on ..." 46.108.133.2 (talk) 16:38, 3 March 2012 (UTC)

NPOV
Okay, we're back to edit warring over authority vs. diversity. Per NPOV, we're supposed to provide all significant angles, without choosing sides other than by WEIGHT. Per WEIGHT, the IAU definition of 'planet' is the basis for organizing the article, which I think is right. However, some astronomers, such as Alan Stern, continue to push for other definitions. We cover that in the article, but it needs to be reflected in the lead. Anything wrong with the following wording?


 * A planet (from Greek πλανήτης αστήρ planētēs astēr "wandering star") is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and—in the definition used by the International Astronomical Union—has cleared its neighbouring region of planetesimals. [...]
 * Planets are generally divided into two main types: large, low-density gas giants, and smaller, rocky terrestrials. Under IAU definitions, there are eight planets in the Solar System. In order of increasing distance from the Sun, they are the four terrestrials, Mercury, Venus, Earth, and Mars, then the four gas giants, Jupiter, Saturn, Uranus, and Neptune. Six of the planets are orbited by one or more natural satellites, of which 19 are of planetary mass.
 * In addition, the Solar System is thought to contain hundreds or perhaps thousands of icy-rocky dwarf planets, five of which have been accepted by the IAU so far. [list in fn] Both the planetary-mass moons and dwarf planets are included as planets by some astronomers, for three types of planet (gas giants, terrestrials, and dwarfs). There are also innumerable small Solar System bodies below planetary mass.

— kwami (talk) 05:52, 2 February 2012 (UTC)


 * Kwami, this is more of your long-running efforts to rewrite pages per your personal preference. Your repeated attempts were rejected at the dwarf planet article, so please don't try to drag it onto this one. Differing opinions can be covered in the body, if consensus dictates, but your tendentious rewrites of numerous articles relating to dwarf planets is not acceptable. --Ckatz chat spy  05:53, 2 February 2012 (UTC)


 * No, Ckatz, this is not my opinion. I don't even agree with it. But it's a matter of WP policy. I'm sorry if you are unable to understand this, but we are an encyclopedia, and as such we need to reflect the breadth of opinions out there. (And it's not part of the DP debate.) Alan Stern was head of NASA and leads the Pluto mission; he is very publicly pushing for a broader def of 'planet'—and he is not alone. This is important enough to include in the body of the text, and the lead is supposed to summarize the body. Certainly in a FA. Now, do you have any factual criticisms of the proposed wording? Any comments about improving the article? — kwami (talk) 06:00, 2 February 2012 (UTC)
 * Factual? Yes, it is a fact that you are engaging in disruptive editing to push through your preferred text. You've been disrupting the dwarf planet article for months now, ignoring consensus, discussion, and your fellow editors, and you show no signs of letting up this disruptive behaviour. --Ckatz chat spy  06:29, 2 February 2012 (UTC)
 * Okay, you're clearly having a problem here, but all of that is irrelevant. I made a change to the lead, you reverted it, and now we're at Talk. How is that disruptive?
 * Again, do you have any comments on the point at hand? — kwami (talk) 06:43, 2 February 2012 (UTC)


 * Under any non-arbitrary definition, there is the category of the dominant eight, which are most commonly called "planets". Even people like Alan Stern recognize the category. We could (I'd say we should) word the lede to be clearly not about the word planet, but about the category. We could say that some lump the dominant eight+DPs(+round moons) together under the term "planet", and use a different word (e.g. überplanet) for the dominant eight. We could then state the article is specifically about the dominant eight. IMO, WP articles should be about concepts wherever possible, not words. Here, that is clearly possible. --JorisvS (talk) 10:58, 2 February 2012 (UTC)


 * That sounds reasonable. We could even develop planemo into an article that would cover Stern's concept of "planet". Any specific changes in wording? — kwami (talk) 13:28, 2 February 2012 (UTC)


 * Leave uberplanet out of it. This article is about the dominant 8 planet-mass bodies in the Solar System. I am sitting on the fence for most of this, but the intro about the 8 dominant planets (+lesser bodies) is not the place to debate Stern's concepts that are not accepted by the general public (ie: Our moon is not a "publicly accepted" planet.) -- Kheider (talk) 14:05, 2 February 2012 (UTC)


 * But we do discuss it in the text, and the lead is intended to summarize the text. True, the Moon is not 'publicly' accepted as a planet, but Pluto still is by many. (Anyway, the Moon nicely illustrates the consequences of a purely physical/geological conception of 'planet'.) Also, it's not just Stern's POV; others, including a number of the public, accept DPs but not satellites as planets (I suspect there are more in that camp, but don't have any figures). By keeping such views out of the lead, we're effectively saying they don't exist. We can say, as Jorisv suggests, that this article is about the dominant 8, and if the reader wants other views, they should go to [planemo/DP/wherever]. — kwami (talk) 15:14, 2 February 2012 (UTC)
 * I agree with Ckatz: you are again trying to push your own personal opinion at the expense of fundamental Wikipedia polices. Ruslik_ Zero 18:44, 2 February 2012 (UTC)

Do we really need to: I fail to see why we need to get too complicated (and political) in the lead. -- Kheider (talk) 22:29, 2 February 2012 (UTC)
 * Put on every major dwarf planet candidate and planet article on Wikipedia?
 * Do we really need to suggest that the Earth-Moon system is a double planet in the lead?
 * Should I tag the Earth article because it does not mention that it is a double planet (according to some)?
 * Should I edit Saturn to state, "With 8 gravitationally bound planets, the Saturn planetary system is largest in the Solar System?
 * No, hence my suggestion: Just note that some people may mean something else when they use the word "planet" (for NPOV reasons) and refer the reader elsewhere and have the rest of the article simply be about the dominant eight. This to avoid letting it get complicated. --JorisvS (talk) 23:35, 2 February 2012 (UTC)


 * Kheider, I don't think you have RS's to say any of those things. We have a very simple criterion for inclusion on WP: if noted astronomers said Earth–Luna was a binary planet, yes, we would need to say that in the lead. If they said the Saturnian system was the largest planetary system in the SS, then yes, we would report that too. But since they don't, we don't. Also, we don't cover such opinions in the articles, so it would be out of place if mentioned in the lead alone, as the lead is supposed to recap the text. In this case, however, we have a very public and protracted debate by several noted astronomers, one which is already covered (adequately, IMO) in the text. — kwami (talk) 04:17, 3 February 2012 (UTC)


 * If you do not like the idea of Earth being an obvious double planet then we do not need to spend time in the lede going into details about Stern's planet-moons. Stern's idea is reasonable (it is what Galileo used), but people have been taught that planets directly orbit stars for years. This will not be settled on Wikipedia. -- Kheider (talk) 12:38, 3 February 2012 (UTC)


 * Which is why we follow sources. Why is that such a difficult concept for you to grasp? — kwami (talk) 02:26, 4 February 2012 (UTC)


 * Per DUE, in the lede planets should orbit stars. I added the one generic comment that the lede needed. We follow sources, but we also give due weight to them, especially in the lede. -- Kheider (talk) 03:03, 4 February 2012 (UTC)


 * Agreed re. due weight, and that is an improvement. — kwami (talk) 11:42, 4 February 2012 (UTC)

Not exactly sure where to put this comment with the -outdent- above, but to comment on the original entry’s "Per WEIGHT, the IAU definition of 'planet' is the basis for organizing the article, which I think is right. However, some astronomers, such as Alan Stern, continue to push for other definitions. We cover that in the article, but it needs to be reflected in the lead." - the controversy *is* reflected in the lead, the opening paragraph closes with that. And at least to me, it seems adequate. Rwessel (talk) 06:49, 3 February 2012 (UTC)


 * Fair enough, though as I'm reading it, it isn't clear that, when we say what a planet is in the first line, it's the 2006 definition that we're using, and that the first line is the point of contention for the criticism mentioned at the end of the paragraph. (True, it's in the footnotes, but normally we shouldn't have to read the footnotes to follow the lead of an article.) — kwami (talk)


 * The IAU definition has been subject to some strong and valid criticisms. Our ideas on what planets are, how they form, how abundant, and how much variation is to be found in arrangement of planetary systems, have been in much flux in recent years since the definition was arrived at. This is a rapidly developing area of knowledge and the appropriate weight should be given in the article to these valid criticisms. The definition is too clean for what is increasingly becoming a much more messy reality. Maybe when we find a super-Earth moon around a gas giant planet this will change. Sky Machine   ( ++ ) 08:36, 3 February 2012 (UTC)


 * If Earth is not an obvious double planet, I would NOT hold your breath that a double gas giant (that can not be seen up close) will change anything. -- Kheider (talk) 03:06, 4 February 2012 (UTC)


 * Perhaps the end of the paragraph could be reworded as follows: "In 2006, the International Astronomical Union officially adopted the above definition in a resolution defining planets within the Solar System. This definition has been both praised and criticized, and remains disputed by some scientists."  Rwessel (talk) 10:03, 3 February 2012 (UTC)

Given the lack of further discussion, I put in a comment about whose definition we're using. I also removed the bit on DPs, since it's off topic and any attempt at NPOV wording causes fights. (Best estimates are that there are hundreds of DPs, not "at least five", which is seriously misleading.) — kwami (talk) 02:19, 11 February 2012 (UTC)


 * Removed, again; the fact that people have grown frustrated with your repeated attempts to modify dwarf planet-related material does not mean there is consensus for you to implement them. --Ckatz chat spy  03:50, 11 February 2012 (UTC)


 * Then we're back to tagging the article, until you get over your unhealthy authority fetish. The lead sentence is a very specific definition of "planet", that of the IAU. It's a perfectly good definition, but we need to be honest with our readers whose it is. — kwami (talk) 05:35, 11 February 2012 (UTC)
 * See, there you go again - it's always something wrong with the person who disagrees with you. Today, I have a supposed issue. Other days, it's Ruslik who is the problem, or Kheider, or whoever happens to say no to you. Tagging a featured article because you aren't getting your way is disruptive and damaging to the project. --Ckatz chat spy  06:14, 11 February 2012 (UTC)
 * Kheider I can work with, because he's willing to work with other people. Most sources follow the IAU def, and therefore so should we. But we need to reflect that there are other views out there, not just Stern and astronomers who agree with him, but historically, within astrology, etc. When we give a definition of a disputed term, it's a no-brainer that we should say whose definition we're using. — kwami (talk) 06:25, 11 February 2012 (UTC)
 * This amply demonstrates why what you are doing is POV pushing: it has been agreed for a long time that astrology has no place in scientific articles. Ruslik_ Zero 07:51, 11 February 2012 (UTC)
 * But "planet" is not inherently scientific. That's why we need to establish that this is a scientific article. Stating that we're following the IAU def establishes that. — kwami (talk) 12:09, 11 February 2012 (UTC)
 * And again, there are already two sentences *in* the lead paragraph (out of six), that say (1) where the current definition comes from, and (2) that there's a controversy. This is more than adequately covered.  Rwessel (talk) 09:51, 11 February 2012 (UTC)


 * No, it doesn't say that. You'd have to go to another article to know that the 2006 definition is the one we'd use. That's not professional. And again, we state the definition as if it were a fact, when it's actually a convention that's not even universal within planetary astronomy. — kwami (talk) 12:07, 11 February 2012 (UTC)


 * The last two sentences in the lead summarize the issue adequately. The lead is not the place to go into excess detail about what Alan Stern prefers or that the Sun and moon use to be a "planets" since they wonder across the sky. -- Kheider (talk) 14:58, 11 February 2012 (UTC)


 * You already accept that covering this is appropriate, so it's odd you would call it "excessive detail". It's only appropriate to say whose definition it is. The last two sentences only summarize this for those who already know the facts, but a lead is targeted to those who don't. — kwami (talk) 15:26, 11 February 2012 (UTC)

Work needed
Hello everyone! This article currently appears near the top of the cleanup listing for featured articles, with several cleanup tags. Cleanup work needs to be completed on this article, or a featured article review may be in order. The tags should either have the issues they refer to fixed and then the tags removed or, if they are unjustified, simply removed. Please contact me on my talk page if you have any questions. Thank you! Dana boomer (talk) 21:18, 6 February 2012 (UTC)

Incomplete ref
The ref No. 29 says just "Joseph, 408". It probably refers to a book by some Joseph, but there is no more information. Jan.Kamenicek (talk) 23:41, 2 March 2012 (UTC)
 * Searched the history to see when it was added, and no it never had a corresponding citation. So removed.  Serendi pod ous  09:40, 3 March 2012 (UTC)

One PDF is listed as a dead link, but it works. Can't say why.  Serendi pod ous  11:24, 3 March 2012 (UTC)

Here is a thought, put measurements into easily recognizable unites, like kilometers for world diameters. Using 1 Earth as astandard is pretty much meaningless to most people. 173.53.79.191 (talk) 03:01, 25 May 2012 (UTC)

Alleged medieval observations of transits of planets
The observation of transits of planets by Avicenna and Ibn Bajjah is quite improbable, if not impossible. See also the discussion at Talk:Transit of Venus/Archive 1. --Jan.Kamenicek (talk) 19:02, 13 July 2012 (UTC)

Former classifications
please split  this. make "Timeline of planetary classifications" - make it in similar to the "objects by size" set-up! heck, even add the time when Neptune and Pluto were the 9th and 8th planets — Preceding unsigned comment added by 76.127.16.19 (talk) 21:49, 15 August 2012 (UTC)


 * Well, why? — Meanwhile I wonder why the first four asteroids are separated from the next eleven. Weren't they all reclassified at the same time and for the same reason? —Tamfang (talk) 00:39, 16 August 2012 (UTC)
 * When were the first four and the next eleven discovered? People didn't feel a need to reclassify four 'planets' in the asteroid belt, but they did when it turned out there were not a few, but many bodies there. --JorisvS (talk) 09:49, 17 August 2012 (UTC)
 * The first four took longer to be reclassified than the others.  Serendi pod ous  10:13, 17 August 2012 (UTC)
 * My understanding is that all the asteroids (minor planets) got the boot in the 1850s. I am sure there was a generation of astronomers that treated the big 4 as special. -- Kheider (talk) 10:38, 17 August 2012 (UTC)
 * Yes, they all got reclassified simultaneously. Somehow the first four were discovered shortly after one another, then for a long time none were discovered, and after that asteroid discovered began to take off, forcing reclassification. --JorisvS (talk) 13:14, 17 August 2012 (UTC)

Archive reorganisation
I've just gone through the archives for this page and noted that there was a massive disparity between the largest and smallest pages. This is partly my fault and partly a legacy of the spats we had here over the definition in 2006. I've had a go at evening them out, so now they're all roughly 100k. I've also reduced the number of archives from 7 to 5.  Serendi pod ous  15:57, 28 August 2012 (UTC)

Number of DPs
Saying the SS has "at least 5 DPs" is a serious misrepresentation of our sources. No-one says that. IAU pubs estimate hundreds if not thousands of DPs. (Okay, found one from 2006 that says dozens or more; we have others around here w higher.) There are 5 individual bodies which they have accepted as DPs, but that is not a claim about the number of DPs in the SS. (If s.o. argues that "at least 5" could mean hundreds or thousands, no normal reader would interpret it to mean that.) — kwami (talk) 02:41, 10 November 2012 (UTC)
 * Reverted again, please resolve this before changing again K. I have merged your notes into the ref. Let's not have the DP argument spill onto yet another page. --Ckatz chat spy  06:47, 10 November 2012 (UTC)


 * I don't know where this comes from, since you have no reference that the estimated number of DPs is anything close to five. Since the number is not ref'd, and neither DPs nor SSSBs are the topic of the article, I've removed the sentence for now. — kwami (talk) 07:54, 10 November 2012 (UTC)
 * And that's restored as well. Seriously - you're challenging that there's at least five? Please resolve this here first, or else we have to go back to the way it was before you initially changed it. --Ckatz chat spy  11:05, 10 November 2012 (UTC)


 * Of course I'm challenging it. We could say there are "at least 20 stars in the galaxy", and if you wanted to be ridiculous you could point out that it's technically true, but it would still be a stupid thing to say. When you say "at least", you imply that is the lower boundary. Why you would edit war to restore a statement like that is beyond me. Please provide a single RS to back it up. As for "or else we have to", that would be WP:POINTY edit. — kwami (talk) 11:41, 10 November 2012 (UTC)

Color distribution
There's a NASA sourced color distribution diagram for Solar System planets in this article Do you think it would be a good addition? -- 70.24.186.245 (talk) 14:34, 10 November 2012 (UTC)

"rogue" planets don't orbit stars?
There is a news article reporting a paper published confirming discovery of a rogue planet, a planet that is not orbiting a star. This article says that planets orbit stars... see where I'm going with this? 68.174.97.122 (talk) 14:47, 14 November 2012 (UTC)
 * What is a planet depends upon it having cleared its neighborhood. If it is in direct galactic orbit, that criterion is not even applicable. Any rogue planemos (planetary-mass objects) are therefore not planets, even though "rogue planet" is often incorrectly used in place of "rogue planemo" (as does the news article). --JorisvS (talk) 14:53, 14 November 2012 (UTC)
 * "Minor planets" and "dwarf planets" are also not planets as they are more or less used as compound nouns. -- Kheider (talk) 15:14, 14 November 2012 (UTC)

Contradictory relative size in pictures
In the first picture on the page Uranus and Neptune are larger than Jupiter, in the first picture in the section "Solar system", Jupiter is the largest of the planets. This source seems to agree with the second picture; I also seem to remember Jupiter as being the largest of the planets. Also the first image doesn't include Saturn, which is strange, because it includes objects like the moon and Haumea, but this isn't really important. I suggest either removing one of the pictures, or changing the description to state that one of them is only to show the color of the planets. If there is a reason why they're not contradictory, I'd like to hear. ---Tacit(not registered) 193.190.253.144 (talk) 06:53, 1 February 2013 (UTC)
 * In the 1st picture what you think is Jupiter is Venus. -- Kheider (talk) 06:58, 1 February 2013 (UTC)
 * You're right, it is Venus. My apologies, I only glanced over the description and thought it was Jupiter because of the texture. Is the reason for not including Saturn and Jupiter in that picture, their size? ---Tacit(not registered)109.132.10.82 (talk) 15:53, 2 February 2013 (UTC)

Uwingu/IAU controversy over the naming of exoplanets
A bit of a kerfuffle has arisen over the naming of exoplanets. The International Astronomical Union apparently thinks they do, or ought to, have a monopoly on the naming. Other scientists disagree, including the planetary scientists and cosmologists behind Uwingu. Here's the link to the news story from a reliable source, the science reporter at NBC News: Who gets to name alien planets?  May be relevant to the articles re planetary naming in general, and the putative names of the many newly discovered exoplanets in particular. Cheers. N2e (talk) 13:40, 21 April 2013 (UTC) l
 * Bunch of con artists bilking money from the public, just like the International Star Registry. We need pay them no heed.  Serendi <sup style="color:#bb0000;">pod ous  15:31, 21 April 2013 (UTC)

Atmosphere of Pluto
Around the bottom of this page, there is a box about planets and their atmospheres (or lack thereof). However, this article claims that Pluto's atmosphere is temporary, though new research has proven that it is in fact permanent, as show here. 134340Goat (talk) 08:08, 8 September 2013 (UTC)

NASA Kepler telescope helps identify 715 new planets outside our solar system
Headline-1: Planet bonanza: NASA announces discovery of 715 new worlds "NASA says its Kepler telescope has discovered a bonanza of 715 planets outside our solar system, pushing the number of planets discovered in the galaxy to about 1,700."
 * http://www.foxnews.com/science/2014/02/27/nasa-announces-mother-lode-new-planets-715/?intcmp=trending

Headline-2:  ‘We Almost Doubled Just Today the Number of Planets Known to Humanity’  " "Our galaxy is looking far more crowded and hospitable. NASA on Wednesday confirmed a bonanza of 715 newly discovered planets outside our solar system." "Scientists using the planet-hunting Kepler telescope pushed the number of planets discovered in the galaxy to about 1,700. Twenty years ago, astronomers had not found any planets circling stars other than the ones revolving around our sun."
 * http://www.theblaze.com/stories/2014/02/26/we-almost-doubled-just-today-the-number-of-planets-known-to-humanity/

Headline-3: '''NASA Scientists Discover 715 New Planets — Data From Kepler Space Telescope Suggests 4 Alien Worlds Have Potential for Life''' NOTE: This is a subscription article: "NASA scientists announced Wednesday the discovery of 715 . . ." — Charles Edwin Shipp (talk) 14:09, 27 February 2014 (UTC)
 * http://online.wsj.com/news/articles/SB10001424052702303801304579407340824861278?mod=WSJ_hp_EditorsPicks&mg=reno64-wsj&url=http%3A%2F%2Fonline.wsj.com%2Farticle%2FSB10001424052702303801304579407340824861278.html%3Fmod%3DWSJ_hp_EditorsPicks

Rogue planets
I've removed the following paragraph.

"More recently, with the discovery of several rogue planets in interstellar space, a planet is no longer defined as being in orbit around a star. Although rogue planets are thought to have been originally formed in stellar orbits, later to be ejected from their solar systems. The origins of rogue planets are still however not known for certain."

The definitions used by the IAU and by exoplanet catalogs do not classify "rogue planets" as planets. There have been no discoveries of objects known to have been ejected from their system. There have been free floating planetary mass objects discovered but it is not true to say that they are all thought to have been originally formed in stellar orbits. Astredita (talk) 05:52, 22 July 2014 (UTC)

Chiron
2060 Chiron probably should be added to the 'Objects formerly considered planets' table. When it was discovered in 1977, media reports briefly called it the 10th planet. It's now classified as a Centaur asteroid. CFLeon (talk) 04:59, 21 January 2015 (UTC)
 * It was just a media speculation. The media doesn't define what's a planet or not. I'm still not quite sure if we should add that Tetra quark (don't be shy) 05:44, 21 January 2015 (UTC)
 * Agreed. The IAU defines what are planets and what aren't. Perhaps some digging on what they've said on Chiron is in order. RegistryKey(RegEdit) 05:45, 21 January 2015 (UTC)
 * Numerous people, including astronomers, disagree with the IAU, preferring their own definition of "planet". Their definitions should be in this article, as well, if notable. &mdash;  Rickyrab. Yada yada yada 18:25, 25 January 2015 (UTC)
 * I also agree. 'Objects formerly considered planets' should contain objects like Ceres and Pluto, which genuinely were widely called planets, not just a little bit of silly media speculation. Reyk  <sub style="color:blue;">YO!  07:58, 21 January 2015 (UTC)
 * People in general define what a planet is. The IAU is one voice, and their grammar is bad (they consider a dwarf planet not to be a planet! Why not call them super-asteroids, if you want to exclude them from planethood? Or, better yet, call them non-orbit-clearing bodies?) &mdash;  Rickyrab. Yada yada yada 18:25, 25 January 2015 (UTC)
 * Because those things are horrible to use. Moreover, there is a long tradition in English for parallel things: minor planets are not planets either and sea lions are not lions. --JorisvS (talk) 10:27, 29 January 2015 (UTC)

Lead images
Shouldn't we choose better images to put there? There are dwarf planets, the Moon, and even a white dwarf star there. Perhaps we should choose planet-only images Tetra quark (don't be shy) 05:51, 21 January 2015 (UTC)
 * Go ahead. The lead images have been the subject of a lot of fire, so I've basically given up taking a position. But if you want to change them, fine.  Serendi <sup style="color:#bb0000;">pod ous  11:43, 21 January 2015 (UTC)
 * It makes a lot of sense. Plus, the ones originally used were more artistic than realistic. I've gone ahead and replaced it. --JorisvS (talk) 12:43, 21 January 2015 (UTC)
 * Still don't love it, but I think a bit smaller would be better. I was playing with the sizes a bit, I think around size=300.  Rwessel (talk) 21:18, 21 January 2015 (UTC)
 * There is definitely still room for improvement. Maybe 400 is often a bit too filling, with the bottom possibly not shown when the top of the page is displayed, yet 300 may be a bit smallish. What about 350? --JorisvS (talk) 22:38, 21 January 2015 (UTC)
 * My main issue with it is that it focuses on the planets of the Solar System, which is a decidedly "20th century" outlook. Planets are no longer only a solar province.  Serendi <sup style="color:#bb0000;">pod ous  22:59, 21 January 2015 (UTC)
 * I don't think that can be called an issue. Yes, an artist image of an exoplanet would fit well, but the main problem seems to be the size. (edit: set size 300. All planets clearly visible)Tetra quark (don't be shy) 23:25, 21 January 2015 (UTC)
 * Unfortunately, there are no images of exoplanets. Maybe a graph of the number of known exoplanets? --JorisvS (talk) 09:16, 22 January 2015 (UTC)
 * As I said, an artist concept of an exoworld can be good enough. Here is a list of some Earth like planets that possibly have illustrations: List of potentially habitable exoplanets. Again, adding an illustration of an exoplanet isn't urgent or anything Tetra quark (don't be shy) 16:05, 22 January 2015 (UTC)
 * I'd prefer one with less black in it, if we decide to have one. As for a graph, what about File:KnownExoplanets-Sizes-20140226.png? --JorisvS (talk) 15:44, 23 January 2015 (UTC)
 * Well, I personally think it is too detailed for a lead image Tetra quark (talk) 15:59, 23 January 2015 (UTC)
 * Any image used should be representative of the known population. Do you have good suggestions? --JorisvS (talk) 16:20, 23 January 2015 (UTC)

List of directly imaged exoplanets Marteau (talk) 16:07, 23 January 2015 (UTC)
 * Sure, but none of these are usable for the lead here. --JorisvS (talk) 16:20, 23 January 2015 (UTC)
 * You said you prefer one with less black in it. I can crop an artistic image and upload it to commons if you wish. Just let me know Tetra quark (talk) 16:41, 23 January 2015 (UTC)
 * Aside from less black, I'd like a representative image. So, maybe one with a mini-Earth, a super-Earth, and say two types of giant planets (Sudarsky's gas giant classification). --JorisvS (talk) 16:49, 23 January 2015 (UTC)
 * I think what you're trying to say is that you want an image that represents one specific planet that couldn't be any other one. There is a NASA list of artist concepts here and a description for each image, so check it out and see if you like one any of them. Then I will crop the image and upload Tetra quark (talk) 17:01, 23 January 2015 (UTC)
 * Maybe the first of, the third of , and the class 2 and 5 of Sudarsky's gas giant classification. This gives a hot mini-Earth, a super-Earth, a hot jupiter, and a gas giant in the habitable zone. I think this shows some variety not present with the Solar System eight. --JorisvS (talk) 16:36, 25 January 2015 (UTC)

Controversy over IAU definition of "planet" in 2006 and to present day
How come there's no mention of the controversy over the IAU's definition of "planet"? It is misleading to state that "A planet is...", only mentioning the IAU definition of "planet", without pointing out that some astronomers and laypeople disagree with the IAU. At the very least, some mention should be made of alternate definitions of the word. &mdash; Rickyrab. Yada yada yada 19:25, 25 January 2015 (UTC)
 * http://time.com/3429938/pluto-planet-vote/ ...no comment.  &mdash;  Rickyrab. Yada yada yada 19:29, 25 January 2015 (UTC)
 * That article doesn't give an alternate definition; in fact one of the scientists argues there shouldn't be one, which is not particularly helpful from our point of view.  Serendi <sup style="color:#bb0000;">pod ous  21:13, 25 January 2015 (UTC)
 * A small audience at a public talk informally decide something and Wikipedia is suppose to pay attention? This meaningless 18 Sept 2014 debate has been discussed before. -- Kheider (talk) 22:39, 25 January 2015 (UTC)
 * There is controversy of course. The arguments are rooted in their failure to understand basic astrophysics from my point of view. It is claimed in this article, "It is not known with certainty how planets are formed", yet that is the problem. Once they come to the obvious conclusion that stars lose their mass by great amounts and cool/die, they will realize that a "planet" is just an ancient, evolved star which is still cooling and dying. It is actually a double whammy if you think about it. Not only do mainstream astronomers not understand how a planet is formed, but it instantaneously means they never understood star evolution itself. This is not good news for them, it is only good news for people outside of those groups. Earth is not just a bunch of water covered rocks, it is an ancient 3.5+ billion year old star at the very end of its evolution, a black dwarf. Star evolution is planet formation itself, they were never mutually exclusive objects to begin with.Wavyinfinity (talk) 08:52, 24 June 2015 (UTC)
 * Wow. I never realised I was so strong, able to move my muscles against the gravity of a collapsed dead star.  Serendi <sup style="color:#bb0000;">pod ous  08:57, 24 June 2015 (UTC)
 * Electrochemical reactions are mediated by the electromotive force, which is 1*10^36, 1*10^39 and 1*10^42 times the strength of gravitation for respective particles proton to proton, electron to proton, electron to electron. So yea, you are that strong, because the force mediating your muscles is beyond gravitation in strength. Fact is, gravity is very, very weak, it can't even hold chemical rockets to the ground. Wavyinfinity (talk) 13:56, 24 June 2015 (UTC)

The article refers to objects "that were once considered planets by the scientific community". Surely, the "scientific community" includes zoologist and pharmacists, and many other kinds of scientists who have nothing more to contribute than any layman? Either the opinion of the astronomical community or the opinion of society at large should be used, but not that of "the scientific community. — Preceding unsigned comment added by 81.107.56.165 (talk) 13:10, 15 October 2016 (UTC)


 * Plus I can go ahead and fix the mess so that the controversy can be settled:

A planet is an ancient, evolving star or stellar remnant.

It will probably be edited out of existence and my user name banned for fixing the problem though. I already get the Wikipedia game, it has to be notable, not be original research, yadda yadda. The fix is so simple though it is shocking. I'm just hoping some other astrophysicists on here see it, so that they can correct themselves.Wavyinfinity (talk) 14:22, 24 June 2015 (UTC)


 * No - the relevant policy is that such a change would need to be supported by a reliable source. And since this notion is massively WP:Fringe, there will be considerable difficulty doing that.  Rwessel (talk) 16:04, 24 June 2015 (UTC)
 * I doubt the relevant word is "fringe". More likely "troll". — kwami (talk) 17:32, 24 June 2015 (UTC)
 * I like the new definition. It agrees with John Dobson's idea that the angular momentum issue cannot be resolved otherwise, unless it is acknowledged that Jupiter's angular momentum could not have possibly come from the Sun, meaning Jupiter is a star, and that the classification of planet vs. star was never needed. Besides, I doubt someone who is trying to solve major issues rates a "troll" designation. Trilliant (talk) 18:43, 17 February 2016 (UTC)

There is controversy, and I am disappointed it is not mentioned here at all. The problem is that the article is entirely written from the astronomical point of view, but there are other disciplines, geophysics in particular, who also use the term planets. In their context, the difference between planet and dwarf planets doesn't make sense, so there is a need for alternative definitions. https://www.lpi.usra.edu/planetary_news/2017/11/06/geophysical-planet-definition-gpd-users-page/ https://www.washingtonpost.com/news/speaking-of-science/wp/2018/05/07/yes-pluto-is-a-planet/?noredirect=on&utm_term=.89130b4282eb https://blogs.egu.eu/divisions/gd/2018/07/25/thirteen-planets-and-counting.WorldsWanderer (talk) 17:33, 3 August 2018 (UTC)
 * The controversy is covered in two separate articles: Definition of planet and IAU definition of planet.  Serendi pod ous  22:20, 3 August 2018 (UTC)

Sun & Moon
Could we have a citation for the claim that the Sun and Moon were considered planets in antiquity? That's NOT what is claimed in the linked article, and hasn't been true for the last three thousand years as far as I am aware. Of course, if you define planet as something that appears to revolve around the Earth, then the claim would be true, but who used that definition?  D b f i r s   21:08, 3 March 2015 (UTC)
 * We can probably grab one from Classical planet. Rwessel (talk) 22:52, 3 March 2015 (UTC)
 * Done, from an academic book I have. The ancient Greeks and medieval Europeans defined a planet as a celestial body that moves relative the the fixed stars. A2soup (talk) 00:38, 4 March 2015 (UTC)
 * Thanks. The "seven wanderers" does indeed seem to be the origin of our modern word planet, so I withdraw my objection and my claim about not being true for three thousand years.    D b f i r s   08:21, 4 March 2015 (UTC)

Moons of Saturn and Jupiter
I'm not an expert on the subject, but I disagree with the classification of the large moons of Saturn and Jupiter as "objects formerly considered planets". It seems that their inclusion in that table is based on the fact that their respective discoverers referred to them as such in the first works that they produced documenting their discovery. There is a big difference between "objects once referred to as planets" and "objects formerly considered planets"-- this was presumably User:JorisvS's rationale for removing Eris as well. Citing Galileo or Cassini or Huygens calling the moons "planets" upon their discovery to justify the claim that they were "considered planets" in a historical sense is a violation of the spirit as well as the letter of WP:NOR. If there are no reasoned objections or reliable secondary-source citations to back up the claim that these moons were "considered planets", I will remove them from the table in a couple days. A2soup (talk) 01:20, 4 March 2015 (UTC)
 * The problem is that the major moons where considered secondary planets in many sources. -- Kheider (talk) 06:35, 4 March 2015 (UTC)
 * I believe it, but I'd like to see some secondary sources covering their historical classification so we can make an informed decision about whether they were really ever considered to be true planets. My view is that if the moons were considered "secondary planets" from the start, then they were never considered to be in the same class as the true planets-- the word "planet" was used simply because no other term for a celestial body existed at that time, not because they were seen as planets like all the others. So it is wrong to say that they were ever "considered planets" in the same way the Sun, Moon, the early asteroids, and Pluto were. Unlike the Jovian/Saturnian moons, these "real" former planets occupied the same place in the cosmos as the true planets, orbiting the Sun (or Earth, depending on the prevailing conception of the cosmos). What it boils down to is that I don't see any secondary sources clarifying the matter. In the absence of such sources, we should not assume that they were considered planets. A2soup (talk) 07:18, 4 March 2015 (UTC)
 * Even in 1782 moons were known as secondary planets. But does that mean a secondary planet was not a planet that moved against the background stars? Looking at Google Books Ngram Viewer, It looks like the terms "primary planet" and "secondary planet" both feel out of favor as the term asteroid became common in the 1860s. I am not sure blanking the term "secondary planet" from this article is in the best interest of the readers. -- Kheider (talk) 22:38, 4 March 2015 (UTC)
 * Interesting-- it's clearly more complicated than I thought at first. I still think they perhaps should go, but I'll look into it myself before I take anything out. Perhaps we can just add a clarification in the table that they were always accorded secondary status and never seen as in the same class as the primary planets? I worry that the way it is now, people will take away the impression that the moons were initially mistaken for planets, like the asteroids or Pluto were, which is very far from the truth. A2soup (talk) 00:19, 5 March 2015 (UTC)
 * I agree the term "secondary planet" needed (still needs?) some kind of disclaimer/explanation. I have added the comment, "They were known as secondary planets". -- Kheider (talk) 16:17, 5 March 2015 (UTC)
 * Thanks for that! Now if we could find a time around when the "secondary planet" terminology became deprecated in favor of "satellite" and "moon", we could make it downright informative. I don't think Google Ngrams is a good enough source, though, and it isn't very clear on the question anyways. I'll poke around and try to find something, but it will probably be quite difficult. Ah, I just followed your secondary planet link, and the linked section seems to provide all the clarification needed. Thanks again for the thoughtful clarification! A2soup (talk) 16:33, 5 March 2015 (UTC)

Greek word for planet
I have noticed the revert of a change of the Greek expression for "planet". However, Wictionary also does not say πλάνητες. It says πλάνης, πλανήτης or πλανάτας. Besides this, I am not sure if Wiktionary is acceptable as a source of information for Wikipedia. --Jan Kameníček (talk) 18:51, 10 March 2015 (UTC)

The correct term is πλανήτες you can in the Greek wiki the term is Πλανήτης Aurilios (talk) 19:04, 10 March 2015 (UTC)
 * πλάνης gives πλάνητες as its plural. There is also πλανήτης, and that has πλανῆται as its plural. This is for Ancient Greek, where the actual origin of term lies. Modern Greek πλανήτης, though, has πλανήτες as its plural. --JorisvS (talk) 19:21, 10 March 2015 (UTC)
 * Thanks for explanation. Meanwhile i found it also at A Greek-English Lexicon]. --Jan Kameníček (talk) 19:34, 10 March 2015 (UTC)

The moon as a classical planet
The IP editor is basically correct, the moon (along with the Sun, Mercury, Venus, Mars, Jupiter and Saturn) was considered one of the seven planets in ancient/medieval times. I would guess that reference #59, the one for the Sun, mentions that, but it's offline and I don't have a copy. We could probably just use reference #1 from Classical planet. In any event, the text should be formatted to match the other entries in that column of the table. Rwessel (talk) 21:24, 7 June 2015 (UTC)

Alternative lead image
Here's an alternative infobox (right side), which I consider an improvement over the existing version (left side). As it is a question of taste, I just post it here on the talk page. What do you think, anyone? -- Cheers,  R fassbind  -talk   08:02, 22 June 2015 (UTC)


 * It has the benefit of showing Saturn a bit larger, but it has more black in it. I like the new caption, which I've put directly into the article, because it is not dependent on this choice. --JorisvS (talk) 10:00, 22 June 2015 (UTC)
 * Thx, the adopted caption is very much appreciated. I've also created a framed version without resizing the images. Maybe that's some kind of compromise. -- Cheers,  R fassbind  -talk
 * I prefer a framed version to what we have now, but don't mind either way between the original sizing and resized version. Both are great. A2soup (talk) 12:16, 22 June 2015 (UTC)

OK, so let's leave the images as they are (i.e. no resizing of Saturn) and just add a frame as this corresponds to the standard layout used on wikipedia. -- Cheers,  R fassbind  -talk   18:34, 28 June 2015 (UTC)

"Planetary mass objects" section
Given that we already have an entire article, Definition of planet, devoted to the ambiguities inherent in the term, is this section necessary, or at least necessary in its current state?  Serendi <sup style="color:#bb0000;">pod ous  20:44, 30 August 2015 (UTC)

Astraea through Eunomia
Should they still be listed in the table for objects formerly considered planets? I haven't been able to find a source that lists them alongside the other planets, something the other four asteroids do have. 2601:195:1:7A71:E828:BBCD:F504:798A (talk) 03:33, 20 May 2016 (UTC)
 * Astraea through Hygiea:, which is in the article. --JorisvS (talk) 16:39, 20 May 2016 (UTC)

Split up List of exoplanets
I have asked to split up List of exoplanets into sublists, for the discussion, see talk: List of exoplanets#Split apart -- 70.51.200.162 (talk) 05:43, 3 March 2017 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on Planet. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20060916161707/http://www.dtm.ciw.edu/boss/definition.html to http://www.dtm.ciw.edu/boss/definition.html

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 15:33, 20 May 2017 (UTC)

Images in lead - are Uranus and Neptune true color?
I suspect that these images have actually been color-enhanced, as they do not appear as such in Hubble photos. In particular, Neptune is much, much lighter than this. 8.40.151.110 (talk) 01:22, 21 November 2017 (UTC)


 * You are correct. As noted in the file description for the current Uranus image, "See File:Uranus.jpg for how Uranus would look to humans in visible light." (The image is much darker.) As for Neptune, a Google search for a true colour image shows that it's far less saturated. The nearest we have to that on the Commons is this image, a derivative of File:Neptune.jpg (which has been repeatedly overwritten). I'll take a copy of the one closest to true colour and upload it as a derivative file for consideration...  nagual  design   02:56, 21 November 2017 (UTC)


 * ...Slight change of plan. I found the original source of the Neptune image at NASA JPL, which I've cropped to the same proportions as the current infobox image and uploaded. Both true colour images are shown to the right. I'll leave it to others to decide whether they should replace those in the infobox. I can add a little whitespace (blackspace?) to File:Uranus.jpg if necessary. I hope that helps.  nagual  design   03:35, 21 November 2017 (UTC)


 * I went ahead and uploaded another true colour image of Uranus with a little more whitespace, using the original NASA JPL source file, as it was easier to do that now rather than later.  nagual  design   03:54, 21 November 2017 (UTC)

Disclaimer: The file description of the Neptune image taken from the NASA JPL source page reads, "This image has been processed to enhance the visibility of small features, at some sacrifice of color fidelity."  nagual  design   04:03, 21 November 2017 (UTC)


 * I went ahead and swapped out the images since the caption underneath reads, "Shown in order from the Sun and in true color."  nagual  design   08:45, 21 November 2017 (UTC)

Semi-protected edit request on 1 February 2018
I want to fix a too big table that makes it difficult to have the entire page in your screen. G.L.Sirius (talk) 13:50, 1 February 2018 (UTC) If you would like to suggest how the table could be "Fixed", without losing any information, or becoming in-readably small, please explain here. Thanks - Arjayay (talk)
 * ❌ This is not the right page to request additional user rights.

Semi-protected edit request on 18 March 2018
Planets are actually celestial beings, not astronomical. 202.153.47.14 (talk) 05:50, 18 March 2018 (UTC)
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. –Ammarpad (talk) 06:18, 18 March 2018 (UTC)

Discussion affecting this WikiProject - The Sun
There is a discussion about whether should redirect to  or to. THe discussion is at Redirects for discussion/Log/2018 July 25. <u style="text-decoration:none;font:1.1em/1em Arial Black;letter-spacing:-0.09em"><u style="color:#7f2ed1">The editor <u style="color:#bfa6d8"> whose username is <u style="color:#7f2ed1">Z0 06:53, 27 July 2018 (UTC)

lea
lajss — Preceding unsigned comment added by 150.242.68.202 (talk) 13:03, 23 August 2018 (UTC)