Talk:Pluto/Archive 7

Archive 1

←

Archive 5

Archive 6

Archive 7

Archive 8

Archive 9

Opening Lines

There has been confusion, at my college even, about the way the article opened previously by stating that Pluto is the largest object in the Kuiper Belt but without mentioning Eris until the issue of mass came up. As far as scientists know at the moment, Eris is a slightly larger Trans-Neptunian Object. Most people (the students here, and the professors haven't mentioned it once during classes!) do not know about the Scattered Disk, and think of all TNOs as either Kuiper Belt or Oort Cloud objects. Some scientific articles even still list Eris as a KBO, not just a TNO. The earlier wording made it SOUND AS THOUGH it were trying to say that Pluto was the largest TNO because it didn't (and still doesn't at that point) say anything about a Scattered Disk. The following statement about mass did mention Eris, but made it sound like Pluto was known to be larger than Eris, just not as massive. There is more information much later, but at that point in the reading the old wording seemed misleading. It would seem unnecessary to break down the definitions of KBOs and SDOs right in the first sentences of the article, so to clarify and avoid confusion I have slightly modified the opening wording to say that Pluto is the second-largest dwarf planet, and THEN that it is the largest KBO. This sticks to all the same facts, but orders it so as to keep relevant information easier to read and understand. MXVN (talk) 21:55, 5 May 2015 (UTC)

The definitions are broken down in the handy footnote right after the first mention. Serendi^podous 22:06, 5 May 2015 (UTC)

The scattered disc is really a quite distinct population. That said, the Kuiper belt consists of several distinct populations, with the hot-classical population possibly more closely related to the scattered disc than the cold-classical population. As for Pluto vs. Eris: Eris is 27% more massive than Pluto, but Pluto is possibly the larger of the two (we'll know for certain this summer after New Horizons has flown by. You should tell your teachers that you've learned that what they teach is too incomplete to paint a correct picture of the situation and that they should get their terminology straight: the Kuiper belt is just one region of the entire trans-Neptunian region. --JorisvS (talk) 08:42, 6 May 2015 (UTC)

Orientation of Pluto's spin axis

I'm surprised to find the article doesn't seem to mention the unusual orientation of the spin axis pointing almost towards the sun. Also the article on Pluto's moons doesn't seem to mention it either, at any rate I didn't see it, unless I'm missing it.

I'd have thought this was an important aspect that should be highlighted. Especially now in build up to the Dawn mission so that the readers can understand its unusual orientation for the mission (with one of its hemispheres currently in permanent darkness, so will need to be photographed using Charon to illuminate it).

See http://spaceplace.nasa.gov/ice-dwarf/en/

for a diagram we could use.

Also for the new horizons mission, another diagram showing both Pluto and it's moons orientation along with the spacecraft's trajectory: http://qph.is.quoracdn.net/main-qimg-8fb3242b253733195de88814ba36453a?convert_to_webp=true

I'd edit it right away, but this surely must be a very high profile astronomy article with lots of editors and watchers, so maybe I'm missing something, as it is such a significant feature of Pluto. Has it has been discussed and there is a reason for not mentioning it? Or is it just an omission, if so then we should "be bold" and just add it in. Any thoughts? Robert Walker (talk) 03:09, 24 May 2015 (UTC)

It's mentioned in the "Rotation" section. Serendi^podous 07:25, 24 May 2015 (UTC)

Oh, so it does, thanks! How about adding the diagram from http://spaceplace.nasa.gov/ice-dwarf/en/ to that section? I mean this image here:

http://spaceplace.nasa.gov/review/ice-dwarf/pluto_orbit.en.gif

It's a NASA image so should be no problem including it, and it might help draw attention to the section as well as helping the reader.

What do you think about that idea? Just a thought. Others might miss it as I did. Robert Walker (talk) 11:45, 24 May 2015 (UTC)

I moved an animated image to the location. Given that all the other images are animated, it makes more sense. Serendi^podous 12:09, 24 May 2015 (UTC)

Okay great, thanks! Yes that's fine, an image helps draw attention and to understand the concept, and an animation is even better. As observed from New Horizons which is approaching Pluto from the direction of the sun. Just a thought, but probably most readers would understand this, could say "taken by New Horizons from the direction of the sun" or some such. Robert Walker (talk) 12:14, 24 May 2015 (UTC)

Possible observation of polar ice cap

Also wondered, what about the possible polar ice cap? I did a search of the page for "ice" and didn't find it. Is it mentioned?

I'd have thought there was enough attention in the news for this hypothesis to be worth a mention, even though of course whatever we write now is liable to be changed within a few weeks, what do you think?

NASA's Best Photos of Pluto Yet Show Possible Ice Cap (Video)

Pluto may have ice cap at pole

Just a suggestion again. Robert Walker (talk) 12:14, 24 May 2015 (UTC)

Well, we'll know for sure in 50 days, so maybe just wait. Serendi^podous 12:25, 24 May 2015 (UTC)

Okay :). Robert Walker (talk) 13:14, 24 May 2015 (UTC)

NASA-Audio (06/03/2015@1pm/edt/usa) - Moons of Pluto - "Surprising" Finds.

NASA-Audio (Wednesday, June 3, 2015@1pm/edt/usa) - Panel of experts to discuss latest "surprising" findings by the Hubble Space Telescope of the Moons of Pluto. - Enjoy! :) Drbogdan (talk) 12:07, 29 May 2015 (UTC)

References

Updating inflation

The article (currently) says "£5 (equivalent to £282, or $430 USD in 2015),", whose code is "equivalent to £{{formatnum:{{Inflation|UK|5|1930|{{CURRENTYEAR}}|r=0}}}}, or $430 USD in {{CURRENTYEAR}})", which looks like the current value in pounds is updated automatically, but not the current value in U.S. dollars. I'm not familiar with these templates, but is there a way to get the US-dollar version to also update automatically using these and maybe another template? --JorisvS (talk) 16:47, 14 June 2015 (UTC)

Rock and ice fractions

The original about Pluto's density and composition said "Observations by the Hubble Space Telescope place Pluto's density at between 1.8 and 2.1 g/cm3, suggesting its internal composition consists of roughly 50–70 percent rock and 30–50 percent ice by mass.". However, its density is known much more precisely than that (which I have corrected), but this means that the mentioned rock and ice fractions do no longer correspond to the density value. Pending a proper source for these, I have hidden this part. Does anyone know of a source that can be used to this end? --JorisvS (talk) 16:22, 18 June 2015 (UTC)

I don't think that precise answer is correct; the only way to determine density is to divide mass by volume, and we don't know what Pluto's volume is, because we don't know what its radius is, thanks to its atmosphere. Serendi^podous 17:54, 18 June 2015 (UTC)

We may not know it exactly, but we do have a good estimate, as the uncertainty in the density shows: 2.03±0.06 g/cm³. The most difficult part would be which densities to use for the components. I've think I've seen 1 and 3.5 g/cm³ somewhere. This would give the equations 3.5a+b=2.03±0.06 and a+b=1, and hence a rock fraction of a=0.412±0.024 and an ice fraction of b=0.588±0.024. However, I don't know if these densities are much good, and hence not how accurate the calculated composition would be. --JorisvS (talk) 09:23, 19 June 2015 (UTC)

Combining the history section

While that is tidier, it does mention Pluto's position in the Kuiper belt before Pluto's position in the Kuiper belt is properly explained in the origins section. Serendi^podous 18:07, 25 June 2015 (UTC)

We could move it if that makes more sense. Then again, "History" sections tend to be the first section in articles. Ours does say "From 1992 onward, many bodies were discovered orbiting in the same area as Pluto, showing Pluto's place within the Kuiper belt", which should be enough for readers to understand the point, IMO (although it could be phrased better, I'll do that in a minute). --JorisvS (talk) 09:59, 26 June 2015 (UTC)

equatorial spots

Anyone want to venture they're a crater chain from the impact of an inner moon? — kwami (talk) 23:59, 2 July 2015 (UTC)

When should we start moving material to daughter articles?

This is already becoming an issue, and it will explode once the New Horizons flyby ends, so we need to start thinking about it now. Serendi^podous 08:20, 4 June 2015 (UTC)

The "Satellites" section is fairlymuch too long. It can be trimmed, with the material moved to the already existing moons of Pluto if it is not there already."

I also think that the "Classification" section is rather long, with some material bordering on off-topic.

The information on its atmosphere and its geology/surface features can be expected to be expanded considerably, which may make it a good idea to split these off to Atmosphere of Pluto and Geology of Pluto (these are currently redirects). --JorisvS (talk) 09:57, 4 June 2015 (UTC)

I have trimmed the "Satellites" section to an appropriate size, though it could still be structured better. --JorisvS (talk) 16:16, 13 June 2015 (UTC)

I have pruned the "Classification" section somewhat, improved its structure and move it to the encompassing "History" section, with which its content groups naturally. --JorisvS (talk) 10:12, 15 June 2015 (UTC)

I have split off atmosphere (almost a week ago) and geology (just now) articles. --JorisvS (talk) 12:25, 7 July 2015 (UTC)

NASA-TV - Pluto Flyby - Updated Schedule (7/12/2015) of Media Coverage

NASA-TV - Pluto Flyby - Updated Schedule (7/8/2015) of Media Coverage. - Enjoy! :) Drbogdan (talk) 11:59, 9 July 2015 (UTC) - UPDATE (7/12/2015) of Media Coverage. - Enjoy! :) Drbogdan (talk) 17:51, 12 July 2015 (UTC)

References

Hypothetical human perspective of the Pluto landscape

I notice this article is a bit lacking in description of what it would be like for a human to look at the landscape. There is reasonable detail at http://pluto.jhuapl.edu/common/content/FAQ.php , but it has some issues. To begin with, it uses a figure of 900 times dimmer than sunlight but 300 times brighter than moonlight that seems to disagree with the million-to-one ratio we have at moonlight. More to the point, I keep thinking there must be some kind of comparison we can use, maybe from around sunrise/sunset or from a particular near total solar eclipse that we have pictures of. I'm not sure - just feel like there must be a better didactic approach. And then there's the issue of the eye damage. Wouldn't it do terrible eye damage if you simply looked at the Sun from somewhere as far away as Pluto? I'm thinking the pinpoint of light is just as hot as when seen from Earth (inverse squares cancel out...) and the relaxed irises in low light are a danger, just as when people watch a near total solar eclipse here. Also, the way the source I cite puts it is "In the dim Pluto daylight, the astronaut may be able to see that the landscape has a yellowish or pinkish color..." which unfortunately is unclear whether it is hard to see color in the ambient light or if they simply didn't know at the time what color Pluto would be. I sometimes feel like colors are ever so slightly visible in moonlight - I think that at even 300 times brighter they should be unmistakeable?? Anyway, we need all this sort of stuff from some usable reliable sources for the article - it can't just be original research. Wnt (talk) 21:18, 9 July 2015 (UTC)

Looks like NASA has followed up on this at http://solarsystem.nasa.gov/plutotime/ - you can find out your own twilight time that has light similar to that of Pluto. But it doesn't talk about the eye damage. Wnt (talk) 16:45, 13 July 2015 (UTC)

Radius

From today's NASA news conference, according to Alan Stern, it appears Pluto's radius is slightly larger than previously thought: 1185±10 km. RandomCritic (talk) 15:30, 13 July 2015 (UTC) I believe that's the solid surface radius, but it should be clarified. RandomCritic (talk) 15:53, 13 July 2015 (UTC)

Here's a citable source: [1] RandomCritic (talk) 17:23, 13 July 2015 (UTC)

Pluto Is More Massive Than Eris?: Confirmed

NASA Link: http://www.nasa.gov/feature/how-big-is-pluto-new-horizons-settles-decades-long-debate

It is now estimated that Pluto is slightly larger the Eris. If this is true, hopefully, it can be added to the Wiki soon.

InterfaceManager

The article only definitively corrects estimates of Pluto's diameter; I've changed the Mass and Size section of the page to reflect that, but there doesn't seem to be any mentioned change in Pluto's predicted mass (in fact, it uses the new found diameter to state that Pluto's density would be slightly lower than predicted, implying no or little change in predicted mass). Greengreengreenred 19:43, 13 July 2015 (UTC)

The mass of both Pluto and Eris have been well known for years. There is small ~2km change in the known diameter of Pluto. -- Kheider (talk) 19:58, 13 July 2015 (UTC)

Semi-protected edit request on 13 July 2015

Pluto (minor-planet designation: 134340 Pluto) is the largest known dwarf planet in the Solar System, which was confirmed on 13th July 2015 by the NASA's New Horizons space probe that Pluto is 1.89% large than the scattered-disc object Eris. It is the ninth-most-massive known body directly orbiting the Sun. It is probably the largest object in the Kuiper belt Mpjacko (talk) 20:22, 13 July 2015 (UTC)

"largest" is too vague. Pluto has a slightly larger diameter, but Eris is more massive. Serendi^podous 20:26, 13 July 2015 (UTC)

PNG issue?

Does the current infobox image look weird to anyone else as a thumbnail? It looks very dark to me. --Njardarlogar (talk) 19:42, 13 July 2015 (UTC)

FWIW - the PNG images look ok atm on our computers - mostly, latest versions of Chrome/Firefox/Opera/Safari & Windows xp/vista/8.1 & related - hope this helps in some way - iac - Enjoy! :) Drbogdan (talk) 20:55, 13 July 2015 (UTC)

NASA confirms Pluto as the largest object in the Kuiper belt

Principal Investigator Alan Stern confirmed that Pluto is the largest object in the Kuiper belt.

• Primary source:
  • Talbert, Tricia (13 July 2015). "How Big Is Pluto? New Horizons Settles Decades-Long Debate". NASA. Retrieved 13 July 2015.
• Other sources:
  • Amos, Jonathan (13 July 2015). "New Horizons: Spacecraft data boosts Pluto's size". BBC. Retrieved 13 July 2015.
  • Drake, Nadia (13 July 2015). "New Horizons Science Update: Pluto Is The Biggest One Of All". National Geographic. Retrieved 13 July 2015.
  • Lakdawalla, Emily. "Pluto minus one day: Very first New Horizons Pluto encounter science results". The Planetary Society. Retrieved 13 July 2015.

National Geographic also wrote that Eris is still more massive. While The Planetary Society reported that Pluto has a radius of 1185±10 km and a diameter of 2370±20 km (so far), according to Stern. This should be updated in the article. Chihciboy (talk) 18:27, 13 July 2015 (UTC)

I see that "Wikipedia employs a restricted definition of Kuiper belt based on information from the Minor Planet Center catalogue" which is still not yet probably updated. It was last updated I think around last week. So should editors at least discuss about this? Chihciboy (talk) 18:39, 13 July 2015 (UTC)

The restricted definition we use actually excludes Eris, so that's not really an issue; the issue for us is that the Kuiper belt still has not been fully charted. Serendi^podous 20:13, 13 July 2015 (UTC)

If it's in reliable sources I suppose we can print it, though it seems like a statistic with little meaning or confidence (shoot a spacecraft past Eris and then we'll see). I assume people will keep updating the radius with more precise figures over the next week. But (knock on wood!) we're expecting to have a lot more interesting stuff to add by then! Wnt (talk) 00:56, 14 July 2015 (UTC)

Semi-protected edit request on 14 July 2015

Pluto has been announced as the bigger dwarf planet by NASA so page needs to be updated Hamody Asgail (talk) 01:22, 14 July 2015 (UTC)

It already has. Serendi^podous 01:28, 14 July 2015 (UTC)

A change in the Radius will produce a change in the Average Density of Pluto

Pluto's new radius is now 1185 +/- 10 Km. If its mass is not changed, but its volume is changed to 6.970 E 18 cubic kilometers, and its mass remains 1.305 +/- 0.007 E 22 kg, then Pluto's Density is reduced to roughly 1872.263 kg / cubic meter ( to a ridiculous number of digits ). This can be broken down into three components. The tri-axial coefficient of compression is small at 6.892 kg / cubic meter. The Uni-axial gravitational coefficient of vertical compression is also relatively small at 286.084 kg/cubic meter, and the combined coefficient of material densities is also low at 1579.287 +/- 10.034 kg/ cubic meter. This means that Pluto has a lot of ice ( various types ), and not much rock. One would presume the rock would find its way to Pluto's center, and the materials in Pluto would stratify with the greatest density materials near the planet's center, and the lightest density materials near the surface. If Pluto was all water ice, its Material Composition number would be in the nine hundreds, and if pluto were all rock like Earth, its Material Composition number would be like Earth at between 2900 and 2904.7 depending on the radius chosen. Since 1579 is below the mid-point between 900 and 2900, Pluto is volumetrically more ice than rock.73.3.187.143 (talk) 04:49, 14 July 2015 (UTC)

Bright feature on Hubble maps?

I was looking at the old HST maps of Pluto and noticed that the bright albedo 'heart'-shaped feature on Pluto is visible in the Hubble images, at 180 degrees in the gif of its rotation. Would this be useful to add to the 'observations' section? exoplanetaryscience (talk) 07:52, 14 July 2015 (UTC)

The flatmap comparisons are most clear, with a similar bright area center to each map. Tom Ruen (talk) 09:07, 14 July 2015 (UTC)

New Horizons

Hubble

updated size info from horizons flyby

Eris is now confirmed to be smaller than Pluto according to latest information. This needs to be reflected in the opening paragraph. Its not exactly much smaller though. Like about 10-15km. Its greater than the margin of error though. — Preceding unsigned comment added by Pepelvamp (talk • contribs) 10:52, 14 July 2015 (UTC)

Largest dwarf planet

Edit by me saying it is the largest dwarf planet by volume and the ninth-largest body by volume directly orbiting the sun has been reverted by Serendipodous by arguing, moons would be larger by volume. Can someone explain the logic behind that? I do not want to start an undo war. Can someone please explain me that? Is a moon directly orbiting the sun or what? Any opinion? I don't like it to be trolled. --Metrancya (talk) 10:07, 14 July 2015 (UTC)

OK, I admit I was overzealous. But there is currently an unresolved discussion about the lead in the talk page section "probably the largest object in the Kuiper belt". Please read that before making any changes. Serendi^podous 10:18, 14 July 2015 (UTC)

Will you idiots please sort out this dispute and stop reverting my changes? I've made good-faith minor edits which have nothing to do with this dispute. User:Serendipodous please note: your argument is with Metrancya, not with me. You never had any reason to revert my work. Colonies Chris (talk) 10:28, 14 July 2015 (UTC)

Then make your minor edits. I have no problem with that. But leave the lead alone. I can't keep the lead the way it is and keep your changes. So make your small changes and I won't go after them. Serendi^podous 10:30, 14 July 2015 (UTC)

I have never changed the lead. You reverted my minor edits along with the changes to the lead by Metrancya, so when I revert your trashing of my work, the lead also changes to the Metrancya version. You never had any reason to revert my changes, as Metrancya pointed out in his edit summary at the time. Colonies Chris (talk) 10:44, 14 July 2015 (UTC)

@Serendipodous: I changed the lead because it summarizes and reflects the current state of the art. I also added the "largest known dwarf planet". Just look at the list of dwarf planets and you will find that I am right. I also changed the saying to "prominent Kuiper Belt object". That isn't wrong either, isn't it? Whether or not it is the largest Kuiper belt object - it doesn't make any statement about that. So no collision with the discussion you are mentioning and therefore no reason to revert the lead. Also see below the next paragraph. --Metrancya (talk) 11:03, 14 July 2015 (UTC)

Please see the above discussion "Probably the largest object in the Kuiper belt". If you want to continue this conversation, do so in that section. Pluto is the largest object in the Kuiper belt. There is no need to pretend it isn't. Serendi^podous 11:06, 14 July 2015 (UTC)

I really don't know what you want. I said all that already. The largest known dwarf planet includes that automatically. And moons are not directly orbiting the sun and are also no dwarf planets. --Metrancya (talk) 11:12, 14 July 2015 (UTC)

The largest known dwarf planet includes that automatically. No it doesn't. Eris and Ceres are both dwarf planets, but they aren't in the Kuiper belt. The fact that Pluto is in the Kuiper belt is the reason it's a dwarf planet. It is, far and away, the most important thing about it. Serendi^podous 11:14, 14 July 2015 (UTC)

Wrong. Eris is a Plutoid like Pluto but an SDO object. Sedna and Ceres are also not Kuiper Belt objects but are also smaller than the largest Kuiper Belt object. Sedna (most likely a dwarf planet from the Oort cloud) is smaller and Ceres is the largest object of the asteroid belt. No minor planet is larger than Pluto. --Metrancya (talk) 11:20, 14 July 2015 (UTC)

I don't get it. What does comparative size have to do with where they are? Serendi^podous 11:25, 14 July 2015 (UTC)

If you don't get it, don't discuss it. Pluto is the largest dwarf planet. Anything against it? No? Pluto is the ninth-largest body directly orbiting the sun. Anything against it? No? In that case I will change the lead again. Please provide substantial arguments if you have anything to say and to discuss. --Metrancya (talk) 11:30, 14 July 2015 (UTC)

It's not my fault if you're not making any sense. The lead, as is, already says Pluto is the largest known dwarf planet. Why remove that it is also the largest known object in the Kuiper belt? Serendi^podous 11:33, 14 July 2015 (UTC)

Good. Made a formatting change. --Metrancya (talk) 11:46, 14 July 2015 (UTC)

Stop it. Just stop it. You are not acting in good faith at this point and are not paying attention to what I am saying. At this point, we need to call in a third party. Serendi^podous 11:49, 14 July 2015 (UTC)

You are arguing with my own words against me. That is pure Nihilism, what you are doing. --Metrancya (talk) 11:54, 14 July 2015 (UTC)

What is an AU?

Would some kind soul please spell out what an 'AU' is? It appears that this is some kind of measure of distance, but there is no hyperlink to any further elaboration of what it is, and in the absence of a fully spelled out name, a non-scientific reader cannot research it further. 174.92.47.35 (talk) 12:06, 14 July 2015 (UTC)

Astronomical unit. 78.55.24.10 (talk) 12:08, 14 July 2015 (UTC)

Tombaugh image

The Tombaugh image was uploaded by someone who incorrectly thought all images found on a NASA website are PD. The image will shortly be deleted from Commons. A local copy can stay on WP, but WP:FUR must be applied in each and every article that uses the image. I can't for the life of me imagine what fair use (by the strict WP standards, not the more lenient US law standards) applies to a Kansas picture of Tombaugh, so I am removing it. A Lowell Observatory publicity photograph associated with the discovery should be used instead. (And as a featured article, all such details must be met.) Choor monster (talk) 12:08, 14 July 2015 (UTC)

Confusing/ambiguous sentence

If Pluto had been given one upon its discovery, the number would have been about 1,164 instead of 134,340. Does this mean If Pluto had been assigned a number upon its discovery, it would have been about 1,164 instead of 134,340.? Ie, was it the 1,164th object in this classification to be discovered? Btljs (talk) 12:31, 14 July 2015 (UTC)

I assume so; however, it isn't a particularly useful piece of information and it isn't cited, so as far as I'm concerned you can just ditch it if you want. Serendi^podous 13:08, 14 July 2015 (UTC)

Semi-protected edit request on 14 July 2015

Caption of first figure should not say "Color image of Pluto, photographed by the New Horizons spacecraft..." a) Grammar: It's not the "image" that's "photographed". It's Pluto. b) Terminology: The word "photographed" is not proper terminology for spacecraft imaging and should not be used. Change caption (and future captions) to: "Pluto imaged in color by the New Horizons spacecraft...". Typonator (talk) 15:37, 14 July 2015 (UTC)

 Done -- Kheider (talk) 15:45, 14 July 2015 (UTC)

parameters

I updated the density per the new radius, but not escape velocity etc. We should get a ref'd value for density though. — kwami (talk) 18:14, 14 July 2015 (UTC)

(Fixed now.)

poles

Sources differ as to whether the north or south pole is now in daylight. Also comments about Charon having a dark polar cap because that's where it's coldest, when of course it's where it's warmest. Just a caution about interpreting recent sources. — kwami (talk) 21:32, 14 July 2015 (UTC)

Request for a third opinion

In the section #"probably" the largest object in the Kuiper belt, consensus was broadly reached that the fact that Pluto is the largest known object in the Kuiper belt should be kept in the lead. However, User:Metrancya has repeatedly removed this information from the lead, and has yet to fully explain his/her rationale. Serendi^podous 11:53, 14 July 2015 (UTC)

My reading of that section is that one editor (Serendipodous) says that "largest known object in the Kuiper belt" should stay in the lede, two (Ashill and Tbayboy) say that it should not due to the ambiguity of the definition, and one (Trystan) thinks that calling it the largest known object in the Kuiper belt is ok but that we shouldn't lead with it. But per User talk:Ashill, I'm happy to not tweak this until the dust settles, though I think that avoiding saying that it's the "largest known object in the Kuiper belt" is the best way to avoid continuous revision by new readers of the article. I'll refrain from further edits to that sentence until the article is off the front page if others want to restore it to a previous version (except for vandalism etc). —Alex (Ashill | talk | contribs) 14:55, 14 July 2015 (UTC)

Note that I'm ambivalent here, agreeing somewhat with both you (Ashill) and Serendipodous. The phrasing was and is (as I'm writing -- it seems to change every few minutes!) such that it is true for either definition of KB. I agree with Serendipodous that placing Pluto in the KB is important in the lead (the belt is why it's not a planet), but I also don't want to immediately "challenge" a reader coming here from reliable sources (e.g., Lackdawalla) that use the more expansive defintion of KB. Tbayboy (talk) 03:46, 15 July 2015 (UTC)

The whole discussion might be part of a larger one (both a scientific and political one in society) which would be dangerous for Wikipedians to enter. This discussion is about the role of Pluto as a planet. Yes, Pluto is a Kuiper belt object. Yes, Pluto is the largest trans-Neptunian object (as of now). Yes, Pluto is the largest Kuiper belt object (as of now but that will probably not change anymore in the future). Yes, Pluto is the largest dwarf planet (as of now). Yes, Pluto is the ninth-largest object in the Solar System directly orbiting the sun (as of now). But some would like to emphasize Pluto's role as an "toppled planet". The lead should be neutral in this respect to avoid Wikipedia becoming a party in this conflict, whether or not Pluto is still a planet. That should be kept in mind also for the following.

From the hierarchical point of view of a description of a body in the solar system: the top-most entry could be 1. dwarf planet (which might be everywhere in the Solar System), followed by 2. transneptunian object (which is the part of the Solar System outside the Neptun orbit), followed by 3. Kuiper belt (which is part of the trans-Neptunian objects and a quite confined disc just outside the Neptun orbit). If one says that Pluto is the largest dwarf planet it therefore automatically means that it is the largest body beyond the in total eight accepted "normal" planets directly orbiting the sun. That covers the Solar System as a whole. Saying that automatically means that this is also the largest object in parts of the Solar System such as the trans-Neptunian objects or objects from the Kuiper belt as the word "trans-Neptunian" already inherits that it is outside the orbits of the eight planets. So simply by saying "Pluto is both the largest dwarf planet and largest trans-Neptunian object and an object in the Kuiper belt" you get all the necessary info. Because in that case Pluto would be the largest dwarf planet solar-system-wide which automatically covers all transneptunian and Kuiper belt objects. You also get the info that it is the largest object beyond Neptun. And finally you get the info that it is part of the Kuiper belt as a subset of the trans-Neptunian objects. --Metrancya (talk) 08:11, 15 July 2015 (UTC)

The orbit

"It has a moderately eccentric and inclined orbit..." "...Pluto's orbit is highly inclined relative to the ecliptic (over 17°) and highly eccentric (elliptical)." Which is it? — Preceding unsigned comment added by 70.113.85.76 (talk) 02:01, 15 July 2015 (UTC)

Eccentric and inclined tompared to the planets, but typical for a KBO. 8.2.215.65 (talk) 02:53, 15 July 2015 (UTC)

That's right. I've fixed them (you actually caught it because I had already fixed it in the lead a while ago). --JorisvS (talk) 09:36, 15 July 2015 (UTC)

Plutodolia

<3 <3 <3 (yup, this is relevant, these astronomers could've sworn they saw a heart on Pluto.) — Rickyrab. ^{Yada yada yada} 04:18, 10 July 2015 (UTC)

More to the point, should we mention this bit of pareidolia in the article? — Rickyrab. ^{Yada yada yada} 04:23, 10 July 2015 (UTC)

I don't think so unless it legitimately ends up being what people remember about the mission. I would give it a week or two after the closest approach to see if anyone still remembers. A2soup (talk) 07:35, 10 July 2015 (UTC)

The Heart was officially named Tombaugh Reggia. SP? — Preceding unsigned comment added by 99.192.14.161 (talk) 19:29, 15 July 2015 (UTC)

Not officially yet. Oh, and as far as Plutodolia is concerned, I'm more partial to this idea. Serendi^podous 19:44, 15 July 2015 (UTC)

bad grammar

This section:

"Pluto's small moons, discovered shortly before and after the probe's launch, were considered to be potentially hazardous, as debris from collisions between Kuiper belt objects and the smaller moons, with their relatively low escape velocities, could have produced a tenuous dusty ring. If New Horizons had travelled through such a ring system, there would have been an increased risks for micrometeoroid damage that could have disable the probe."

could use a grammar check... as written it's pretty pathetic.

123not.it!

revised. Serendi^podous 20:49, 15 July 2015 (UTC)

This:

"Pluto's small moons, discovered shortly before and after the probe's launch, were considered to be potentially hazardous, as debris from collisions between them and other Kuiper belt objects could have produced a tenuous dusty ring. If New Horizons had travelled through such a ring system, there would have been an increased risk of potentially disabling micrometeoroid damage."

is much, much better. Thanks, Serendipodous! -J

Solstice and Equinox

In what year will Pluto next be at equinox? Given its elliptical orbit, I assume the solstices and equinoxes are not at 62 year intervals, but somewhat more irregular. It would be interesting to know when the planet would present 100 percent of its surface to sunlight during a single rotation. GBC (talk) 03:21, 16 July 2015 (UTC)

Too many comparisons

This first photo isn't perfect but the only good one here.

Size comparisons: Left: Earth, Moon and Pluto. Center: Pluto and Charon compared to Earth. Right: Pluto and Charon compared to the United States.

Second is hard to see with the shadows and color selection. Third is too specific to the American reader. --MarsRover (talk) 21:01, 15 July 2015 (UTC)

I agree, I would keep only the first one. I think in general there are far too many (redundant) photos in this article, and this likely will get worse once more and more photos are released. Varianceinvain (talk) 21:35, 15 July 2015 (UTC)

 Done - FWIW - Yes - I agree as well - iac - Enjoy! :) Drbogdan (talk) 22:06, 15 July 2015 (UTC)

Actually, the original two-image version looks better than the single-image. Just to let you know that I had been cleaning up the scattered images, before you added a third one, and now you removed all but one. That's fine with me, but I won't do any image/layout housekeeping anymore and find myself another article to work with. -- Cheers and enjoy! Rfassbind -talk 10:07, 16 July 2015 (UTC)

@Rfassbind: Thank you for your comments - please understand that I'm flexible re this issue - it's *entirely* ok with me to rv/mv/ce the edit of course - after all, there doesn't seem to be a lot of opinions re the issue (or a clear consensus?) at the moment - in any case - Thanks again for your comments - and - Enjoy! :) Drbogdan (talk) 13:10, 16 July 2015 (UTC)

Sure, no hard feelings at all. Hope the article won't get too messy as more and more files are being added. I'll definitely check the article now and then. Cheers, Rfassbind -talk 19:08, 16 July 2015 (UTC)

Missing distance from Earth

As object. — Preceding unsigned comment added by 93.47.243.8 (talk) 09:16, 16 July 2015 (UTC)

Its distance from Earth is its distance from the Sun minus one astronomical unit. Serendi^podous 09:17, 16 July 2015 (UTC)

±1 AU, I may add to the given explanation. Cheers, Rfassbind -talk 09:22, 16 July 2015 (UTC)

Since you don't reason in astronomical units but in kilometers it would be useful to write down the distance in such a unit as well. — Preceding unsigned comment added by 79.18.238.50 (talk) 11:36, 16 July 2015 (UTC)

OK. Plus or minus 150 million km. The real issue is that there is no such thing as "distance from Earth." Both Pluto and Earth are always moving, so the distance between them changes from day to day, let alone from year to year. The best we can say is that its closest possible distance to Earth is 28.657 AU (perihelion minus 1 AU, or 4,287,026,180 km) while its farthest possible distance from Earth is 49.871 AU (aphelion plus 1 AU, or 7,460,595,410 km. So "Pluto's distance from Earth", depending on the time of year, decade, or century, fits into a range of 3,173,569,230 km. At least with the Sun we can say there's an "average distance"; we can't really say that with Earth. Serendi^podous 12:42, 16 July 2015 (UTC)

Thank you for that very concise explanation. That should make sense to virtually everybody. Rfassbind -talk 16:28, 17 July 2015 (UTC)

On 15-Jul-2015, Pluto was 31.9 AU (4.77 billion km; 2.97 billion mi) from Earth. Which each passing year, Pluto is currently getting about 0.2 AU (30,000,000 km; 19,000,000 mi) further from Earth. -- Kheider (talk) 16:46, 17 July 2015 (UTC)

NASA-TV - New Horizons mission - News Conference (1pm/et/usa, Friday, 7/17/2015)

NASA-TV - New Horizons mission - re Pluto flyby - News Conference (1pm/et/usa, Friday, 7/17/2015). - in any case - Enjoy! :) Drbogdan (talk) 13:23, 17 July 2015 (UTC)

BRIEF Followup - Video (55:43) of NASA media conference (1pm/et/usa - 7/17/2015), with the latest images of the Pluto system from New Horizons, is at => https://www.youtube.com/watch?v=xAGwxl7FZWw - in any case - Enjoy! :) Drbogdan (talk) 23:53, 17 July 2015 (UTC)

References

Alternative table "Mass estimates for Pluto"

Here's an alternative version of the wikitable "Mass estimates for Pluto". Instead of fractions, it displays the change in mass as a percentage figure (see tables below). -- Rfassbind -talk 11:56, 18 July 2015 (UTC)

Mass estimates for Pluto" – alternative vs current table version

Mass estimates for Pluto in Earth masses

Year	ME	Change	Estimate by
1915	7	–	Lowell – prediction for Planet X
1931	1	−86%	Nicholson & Mayall
1948	0.1	−90%	Kuiper
1976	0.01	−90%	Cruikshank, Pilcher, & Morrison
1978	0.002	−80%	Christy & Harrington
2006	0.00218	+9%	Buie et al.
2015	0.00220	+1%	New Horizons
Sources: 1915  · 1931  · 1948  · 1976  · 1978  · 2006  · 2015

Mass estimates for Pluto

Year	Mass	Estimate by
1915	7 Earth	Lowell (prediction for Planet X)
1931	1 Earth	Nicholson & Mayall
1948	0.1 (1/10) Earth	Kuiper
1976	0.01 (1/100) Earth	Cruikshank, Pilcher, & Morrison
1978	0.002 (1/500) Earth	Christy & Harrington
2006	0.00218 (1/459) Earth	Buie et al.
2015	0.00220 (1/455) Earth (0.002454 including Charon)	New Horizons

Polar confusion

Our 2003 source say the north pole is in winter. NH maps show the south pole in winter. Our info box had retrograde rotation with 120-degree inclination -- a double negative. I changed the rotation to prograde and left the inclination at 120*, but have no idea if that corresponds to to the convention of our 2003 source or to the NH maps. LORRI animations show illuminated counter-clockwise rotation, which would mean prograde rotation at 120* and northern summer, but that's assuming the images have not been flipped left-to-right. (I guess I'm thinking of telescopic images.) Does anyone know for sure? — kwami (talk) 19:04, 17 July 2015 (UTC)

Using Celestia and the right-hand rule, it's Pluto north pole that is currently in continuous sunlight. --JorisvS (talk) 10:23, 18 July 2015 (UTC)

I commented on this above - according to poles of astronomical bodies, the poles of planets are determined according to where Earth's north pole is. So I think Pluto's demotion switched its north and south poles! But wait, there's more! According to [2], many astronomers were using the "wrong" convention before the switch, which made their maps actually right afterwards about which pole is north and south. But, well, for any given source, who knows? Wnt (talk) 20:49, 18 July 2015 (UTC)

Gallery

I just removed the gallery, as it seemed to be inappropriate per Wikipedia:Image use policy#Image galleries. More importantly, inappropriate per common sense as the gallery was just an indiscriminate collection of images taken by New Horizons. Some of these images are used somewhere else in the article already, others are just images of Pluto taken at different distances. Feel free to revert or readd images, but at least be more discriminate. Not every photo taken of Pluto has to be included in this article. Varianceinvain (talk) 10:39, 17 July 2015 (UTC)

FWIW - reverted edit and restored Pluto#Gallery - please discuss for WP:CONSENSUS per WP:BRD & related - comments welcome - in any case - Enjoy! :) Drbogdan (talk) 11:51, 17 July 2015 (UTC)

And? WP:BRD states that "Consider reverting only when necessary. BRD does not encourage reverting, but recognizes that reverts will happen. When reverting, be specific about your reasons in the edit summary and use links if needed." So what are your reasons? Why do you want to see the gallery included? Or did you revert just for the sake of it? Varianceinvain (talk) 12:48, 17 July 2015 (UTC)

Thank you for your comments - the Pluto#Gallery section of images seems worth keeping imo - especially for the moment due to the current interest in observing Pluto for the first time as a result of the recent New Horizons spacecraft flyby - comments by other editors, to reach a WP:CONSENSUS, welcome of course - in any case - hope this helps in some way - Enjoy! :) Drbogdan (talk) 13:09, 17 July 2015 (UTC)

No, it did not help. You still did not provide a reason, other than stating that it should be kept, in your opinion. Well, very helpful. Surely, as you reverted my edit, you could at least extend the common courtesy to provide a rationale? Especially as Wikipedia policy discourages galleries. Varianceinvain (talk) 15:34, 17 July 2015 (UTC)

Thanks again for your comments - as before - my rationale is presented above - as an improvement to the Pluto article at this time (at least) - per WP:NORULES & related (at least) - also - as before - comments by other editors, to reach a WP:CONSENSUS, welcome of course - in any case - Enjoy! :) Drbogdan (talk) 16:01, 17 July 2015 (UTC)

There is no reason to remove the gallery section. Leave it alone, Rfassbind -talk 16:21, 17 July 2015 (UTC)

I am just astonished by the quality of discussions here. Rules clearly state that galleries are discouraged. I remove the gallery, provide the rationale on the talk page. The edit gets promptly reverted, and the person reverting is not even making an attempt to provide a rationale. As is the other editor. How is Wikipedia going to work if you are not willing to engage in a discussion by providing arguments? Varianceinvain (talk) 18:43, 17 July 2015 (UTC)

WP:Image use policy#Image galleries states: "the use of a gallery section may be appropriate in some Wikipedia articles if a collection of images can illustrate aspects of a subject that cannot be easily or adequately described by text or individual images." Since we currently have many raw images of Pluto showing features that have not yet been written about in reliable sources (and especially not in reliable secondary sources), I think it is reasonable to assume that those images illustrate aspects of Pluto that cannot yet be adequately described in well-sourced text. So a gallery is appropriate. I agree that the gallery here is not very well-crafted, but I think that the proper action to remedy this is to WP:FIXIT, not delete the whole thing. As a final point, if there is ever a conflict between a policy/guideline and our central goal of informing readers, we should choose to inform. A2soup (talk) 19:18, 17 July 2015 (UTC)

BRIEF Followup => rv edit - removing section without WP:CONSENSUS - please discuss for WP:CONSENSUS - per WP:OWN & related => "All Wikipedia content − articles, categories, templates, and other types of pages − is edited collaboratively. No one, no matter how skilled, or of how high standing in the community, has the right to act as though they are the owner of a particular page." - Enjoy! :) Drbogdan (talk) 19:15, 17 July 2015 (UTC)

---

The real issue here is that none of the new images have been incorporated properly. The new images should be included in the Geology subsection with the new information they have provided. Not just lumped at the bottom. Serendi^podous 19:17, 17 July 2015 (UTC)

The gallery makes a fine temporary home for pictures. This isn't a stable article where interested editors are just uploading images because they can. This is breaking news about Pluto, and over time it will be sorted out, and the gallery will fade out on its own. Choor monster (talk) 19:21, 17 July 2015 (UTC)

Kwami, until we incorporate the information provided by those images into the article itself (which we haven't yet) they are the only sources of said info. The closeup image is the only closeup image of Pluto ever taken, the annotated images include lines like "the whale" that are not mentioned in the text. Serendi^podous 20:31, 17 July 2015 (UTC)

Actually, "the Whale" does occur in the article. All occurs in secondary articles as well, like Whale (Pluto) and geology of Pluto. Not every image needs to appear in the main article, and a gallery is not the proper way to present geological detail. And if we are to have a gallery, it should be properly formatted, with no forced widths. — kwami (talk) 20:46, 17 July 2015 (UTC)

"The whale" is named nowhere in the text. Until we get some decent sources outlining what the images mean, we should keep them for the information. I have no problem with proper formatting. Just don't delete them. Serendi^podous 20:59, 17 July 2015 (UTC)

 Done - Brief followup - added to the "Pluto#Surface" section => Notable geographical features include the "Heart" (a large pale area) as well as "The Whale", "The Donut" and "The Brass Knuckles". - seems ok - but *entirely* ok w/ me to rv/mv/ce of course - iac - Enjoy! :) Drbogdan (talk) 21:10, 18 July 2015 (UTC)

Galleries are useful and very common.

Everything on wikipedia should be properly formatted, including galleries. Why not delete the gallery section of Ceres? It had been questioned and deleted before, using the same rationale from WP:Gallery. Obviously the gallery persists. And so are these:

• Comets
  • Tempel_1#Gallery
  • Churyumov–Gerasimenko#Gallery
  • C/2011_W3_(Lovejoy)#Gallery
  • 81P/Wild#Gallery
• Moons of Saturn
  • Enceladus#Gallery
  • Mimas_(moon)#Gallery
  • Dione_(moon)#Gallery
  • Rhea_(moon)#Gallery
  • Iapetus_(moon)#Gallery
  • Prometheus_(moon)#Selected_images "selected images"...

It seems like every now and then, someone comes along and finds a reason to delete one particular gallery. Rfassbind -talk 22:18, 17 July 2015 (UTC)

This article is an exceptional case for use of galleries, since it is both in flux and has a massive collection of free images available of high scientific interest. Optimally, though, the article should be lengthened enough to bring every gallery image to an inline placement with the text. Somebody was making fun of Wikipedia recently for having a shorter article on Pluto than some imaginary villain's homeworld or something, and it's not because there's that little known about Pluto! People just gotta write. Wnt (talk) 20:44, 18 July 2015 (UTC)

Ahem; speaking as the article's chief editor, I would like to dispute the argument re: Cybertron: 1. This article is actually longer than any planet article other than Earth and Mars and 2. We don't tend to include previous ideas of what Pluto was in this article, while the Cybertron article contains every alternate version of the planet. Serendi^podous 20:54, 18 July 2015 (UTC)

The gallery is completely redundant with existing articles. Many of the images have been surpassed and aren't worth including, except perhaps on the NH article. Ones that are actually useful (best views from different angles, false color, etc.) are worth keeping. If we're only keeping the rest for editors to use, that's what image categories are for. — kwami (talk) 23:28, 18 July 2015 (UTC)

Rotation (and the north pole)

From recent images we see Pluto's north pole on top and rotation direction is counter-clockwise as viewed from above. But rotation period of Pluto is negative, so it should rotate clockwise, i.e. from east to west as viewed from the northern hemisphere of the Earth. Does this mean that on images we see Pluto upside down and north pole should be on the bottom if seen from the northern hemisphere of the Earth, not on top as on images? Should these questions be clarified in now small "Rotation" section of the article?188.69.214.120 (talk) 07:48, 12 July 2015 (UTC)

Properly, the north pole is where the thumb points if you follow the direction of rotation with the fingers of your right hand (the right-hand rule). Then, the rotation period is always positive, and a minus sign only used to stress that the obliquity of the body's is larger than 90°. So, when viewed from a body's north pole, it will by definition of what is its north pole rotate counterclockwise. (This would not be the case in the competing usage, though, which is that north is the pole on the same side of the ecliptic as Earth's north pole (which follows the right-hand rule regardless). This one is less simple, easier to confuse poles, and less universally applicable and hence less useful) --JorisvS (talk) 09:32, 12 July 2015 (UTC)

So, as Pluto's obliquity is 120 degrees, its north pole from the nortern hemisphere of the Earth should be seen in the lower part of Pluto's disc,not in the upper, as on recent images, Pluto is upside down on images, as I understand. 188.69.214.120 (talk) 11:01, 12 July 2015 (UTC)

As seen from Earth, yes. But images taken by New Horizons may be (often?, always?) rotated to have north up. --JorisvS (talk) 11:19, 12 July 2015 (UTC)

I think virtually every image official image release (i.e. non-raw image) since May or so has north as up (in the 'polar cap' release from April, the orientation was different). --Njardarlogar (talk) 11:29, 12 July 2015 (UTC)

Australians (and others in the southern hemisphere), I think, see north pole up, as they do see the Moon upside down.188.69.214.120 (talk) 11:45, 12 July 2015 (UTC)

My inference from what I'm reading here (please correct!) is that which way on Pluto is north depends on this silliness about whether it's a planet or not. Because the IAU has a weirdness where they say that the pole of any planet is the pole that faces north relative to the "invariable plane" of the solar system (a strange phrase, isn't it, when we keep finding more and more mass who knows where way out in the boonies?), but any minor planet is according to the straightforward "stars rise in the east" rule (maybe not the Sun, AFAIU). So if Pluto has obliquity 120 degrees, then if it were a planet, it would have obliquity 30 degrees and be spinning with a negative rotation and its south pole for a north pole... right? Wnt (talk) 16:44, 13 July 2015 (UTC)

Pluto and Charon are tidally locked to one another (rotation equals orbit). This is explained under "Satellites", but not even referenced under "Rotation". With intrinsic data exploding regarding the satellites per se, I propose that the entire explanation of the Pluto-Charon mutual tidal lock/facing be moved from "Satellites" to "Rotation". If needed, the cross reference should be from "Satellites" to Rotation (not vice versa). Jeffryfisher (talk) 21:03, 19 July 2015 (UTC)

"probably" the largest object in the Kuiper belt

This line is really bugging me, because it can be interpreted multiple ways. We don't define the Kuiper belt in the lead, so, depending on your interpretation, Eris could be considered part of the Kuiper belt or not. If the casual reader assumes Eris is part of the Kuiper belt, then he or she might interpret the line as referring to the mass vs volume distinction separating Eris and Pluto, rather than the overdetermined argument regarding the utterly minuscule chance that the Kuiper belt as we define it contains an object larger than Pluto, which is what it's really about. I actually think that stating outright that Pluto is the largest object in the Kuiper belt, regardless of it only being 99.9999999 percent probable, is preferable to the current wording. Serendi^podous 00:49, 14 July 2015 (UTC)

I dislike it as well. We could just say it is the largest known object (by both mass and volume) in the Kuiper belt.--Trystan (talk) 00:53, 14 July 2015 (UTC)

Good idea. Revised. Serendi^podous 00:58, 14 July 2015 (UTC)

(edit conflict) Given the ambiguity about definition, I think it's probably best to avoid saying it's the largest object in the Kuiper belt. Defining Eris as not a Kuiper belt object is inconsistent with at least today's New York Times article. The existing sentence in our lede "It is the largest known trans-Neptunian object by volume, but less massive than scattered-disc dwarf planet Eris." covers all bases unambiguously and inarguably (except for a grammatical error which I'll fix, and I think the word "known" can either go or be replaced by "probably"). We can leave whether Eris is part of the Kuiper belt for the main body, where the article can actually explain what is meant instead of relying on specific definitions. —Alex (Ashill | talk | contribs) 01:00, 14 July 2015 (UTC)

Talking about Pluto versus Eris, both Phil Plait and Emily Lackdawalla describe Eris as being in the Kuiper belt. I think it's best to avoid such poorly-defined distinctions. What's wrong with just something like "largest known transneptunian object", which is already in the next sentence anyway? Or switch "TNO" to "DP", or have both. Tbayboy (talk) 02:17, 14 July 2015 (UTC)

Not mentioning that Pluto is in the Kuiper belt is like not mentioning that Ceres is in the asteroid belt. Wikipedia has a working definition; we've sourced it, we've explained it, we don't need to justify it anymore. Serendi^podous 02:19, 14 July 2015 (UTC)

That's okay to mention, since it's not contentious. It's Eris's position that is in doubt. So leave the ranking to the better defined region (TNO). We're not mentioning that Pluto is the largest, most massive plutino, either. Tbayboy (talk) 02:24, 14 July 2015 (UTC)

Why? We've already defined the Kuiper belt. We've used the IAU MPC as a source. We explain the rationale in the Kuiper belt article. Why do we need to constantly kowtow to the opposing position? Serendi^podous 02:31, 14 July 2015 (UTC)

Mike Brown is in that opposition, too. (But it's an old page, he might have changed his position.) However, I think you've convinced me to like what's there, since Pluto is likely to remain the largest KBO, whereas it's still very possible for a larger scattered object to come into view. Tbayboy (talk) 02:45, 14 July 2015 (UTC)

I don't mind mentioning that it is the largest object in the Kuiper Belt, but I wouldn't lead with that, as it Kuiper Belt is a much less well-known thing than Pluto. I think the defining characteristics for the lead sentence (and lead clause) are that Pluto is 1) a dwarf planet and 2) it orbits the Sun/is part of the Solar System. Kuiper Belt can come a sentence or two later.--Trystan (talk) 04:06, 14 July 2015 (UTC)

Again, look at the article for Ceres. Ceres is the largest object in the asteroid belt, and that's what it leads with. Serendi^podous 09:43, 14 July 2015 (UTC)

I've had another crack at tweaking the opening few sentences to avoid the ambiguity about whether Pluto is a dwarf planet while still mentioning its defining characteristics in the opening sentence: "Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt and the first trans-Neptunian object to be discovered." I don't think the fact that we use one definition (which is far from universal and appears to me to be a minority definition) of Kuiper belt in another article makes it clear for readers to use that definition in the lede of this article. Here it's not necessary to use that definition and confusing unless we clutter the lede with not-quite-relevant detail about the definition of Kuiper belt we've adopted. —Alex (Ashill | talk | contribs) 13:21, 14 July 2015 (UTC)

Actually, Pluto being larger than Eris is not at all "99.9999999 percent probable" yet. Comparing the numbers in Lakdawalla's article, Eris is only 34+/-32 km smaller than Pluto. If the error bars given for either DP's size are 1 sigma, the 1.1 sigma error bars of Eris' and Pluto's size already overlap, so Pluto being larger is "only" ~96% probable (2*1.1 sigma=2.2 sigma). Therefore I think the "probably" should stay for the moment, if we mention the "largest" at all. --Roentgenium111 (talk) 12:22, 17 July 2015 (UTC)

PS: Plait gives a lower number for Eris' size, resulting in 44+/- 32 km difference, or a 2*1.5=3 sigma certainty. If this is correct, "Pluto is almost certainly the largest object in the Kuiper Belt", as Plait himself puts it, but it's still not quite certain yet. --Roentgenium111 (talk) 12:57, 17 July 2015 (UTC)

Eris isn't in the Kuiper Belt to begin with. Titanium Dragon (talk) 21:17, 19 July 2015 (UTC)

Exploration of Pluto

The article is >120 kB, and will continue to grow as more science data is released from New Horizons. We have already split off significant sections of this article into separate articles, but Exploration of Pluto is still a redirect. Is it time to split material about New Horizons information and other proposed/scrapped exploration to this location? VQuakr (talk) 20:49, 18 July 2015 (UTC)

One problem with splitting it off is that "Exploration of Pluto" is essentially synonymous with New Horizons, and is likely to remain so. Perhaps it would make more sense to redirect the title there. Serendi^podous 21:16, 18 July 2015 (UTC)

I thought about that. We have Exploration of Neptune and Exploration of Uranus, both of which are heavy on the coverage of their single probe flybys but cover proposed and planned missions as well. VQuakr (talk) 21:19, 18 July 2015 (UTC)

I support the idea, if only because the article would be useful as a place to dump info about the many proposed and cancelled missions, which doesn't belong on Pluto or New Horizons. Substantial overlap and shared text between Exploration of Pluto and New Horizons would be okay IMO, with the former page covering only operations in the Pluto system. The first section after the lead would be New Horizons and have a main article hatnote to New Horizons. A2soup (talk) 23:49, 18 July 2015 (UTC)

I support it as well. In fact, I had been toying with the idea before New Horizons' flyby when I was splitting off articles about its atmosphere and geology. --JorisvS (talk) 10:08, 19 July 2015 (UTC)

Exploration of Pluto is now a thing. That exists. Serendi^podous 10:10, 19 July 2015 (UTC)

"Some astronomers believe Pluto should still be considered a planet."

"Some astronomers believe Pluto should still be considered a planet." is misleading because it makes it appear that some astronomers think that Pluto should be the 9th planet. What they actually mean is that Pluto (along with many other objects) should all be considered planets. An alternative might be:

"Some astronomers believe that the current definition of a planet is too strict and should include Pluto and the possibly hundreds of other objects in the solar system which exhibit gravitational rounding." 96.227.191.173 (talk) 06:11, 20 July 2015 (UTC)

Good idea! To keep it focused on Pluto, how about: "Some astronomers believe that Pluto, as well as the other dwarf planets, should be considered planets." A2soup (talk) 06:15, 20 July 2015 (UTC)

Makes sense. I've made the change. --JorisvS (talk) 09:53, 20 July 2015 (UTC)

Aren't there some that believe that only Pluto should be considered a planet, for a total of nine? Also, Stern believes that the HE moons should be considered planets as well. — kwami (talk) 17:47, 22 July 2015 (UTC)

I can't think of any scientists who believe there are 9 planets in the solar system (or 10, which would be a more logical number given that Eris is almost identical in size and more massive than Pluto).

Among scientists, the most common numbers appear to be 8 (and even fewer?), planets + dwarf planets (examples: David Grinspoon, Gerard van Belle) and planets + dwarf planets + biggest moons (examples: Marc W. Buie, Phil Metzger and of course Alan Stern). --Njardarlogar (talk) 18:35, 22 July 2015 (UTC)

Directly?

Doesn't this; "Pluto and Charon are sometimes described as a binary system because the barycenter of their orbits does not lie within either body." contradict this "directly orbiting the Sun"? Directly means directly after all. If it is orbiting a point outside its barycenter then surely that's its primary orbit, as much as the moon orbits the Earth. If not, why not?121.73.221.187 (talk) 20:52, 6 June 2015 (UTC)

Personally I think orbiting an empty point in space doesn't really count as "orbiting something". Serendi^podous 20:58, 6 June 2015 (UTC)

It's not orbiting an empty point in space; it and Charon are orbiting each other. In exactly the same way in a binary star system the stars orbit each other (where their respective masses places the barycentre outside the bodies of each that is).121.73.221.187 (talk) 21:02, 6 June 2015 (UTC)

In that case, it is directly orbiting the Sun; it's just orbiting the Sun with Charon. Serendi^podous 21:13, 6 June 2015 (UTC)

Then that's not it itself orbiting 'directly'.

di·rect·ly

adverb

adverb: directly

1.without changing direction or stopping.

2.with nothing or no one in between.121.73.221.187 (talk) 21:24, 6 June 2015 (UTC)

Yup, definition #2 applies. If pluto was orbiting a point inside of another body, then it would be orbiting that body rather than the sun (as the moon orbits the earth). VQuakr (talk) 22:45, 6 June 2015 (UTC)

No it really doesn't. Orbiting means going around, it's not directly going around the sun as its primary orbit (any more than Earth's moon is), it and Charon are directly orbiting each other. That orbit is between their orbit and the orbit with the sun.It makes no difference if the centre of that orbit is inside a body or not, it's still the orbit that they have a primary direct relationship with. An orbit is not defined as being within the body of an another object, it's defined by the curved path the body is following. Otherwise you couldn't say binary stars were orbiting each other.121.73.221.187 (talk) 23:00, 6 June 2015 (UTC)

You asked the difference between Pluto and earth's moon; this was answered. VQuakr (talk) 23:05, 6 June 2015 (UTC)

I didn't ask for a difference between Pluto and Earth's moon. I pointed to how they're similar as the defining point of what does and doesn't constitute directly orbiting the sun. The barycenter of both is outside of the body in question, it's the barycentre that's the centre of their orbit, so that's their primary and direct orbit, around each other. The argument that the centre of the orbit is not within another body is moot, as that's nothing to do with the definition of an orbit, as demonstrated by binary systems where stars orbit each other.121.73.221.187 (talk) 23:27, 6 June 2015 (UTC)

I think I kind of agree. If someone describes the Pluto–Charon system as a binary, then each is rather a satellite of the other, and they cannot be said to really orbit the Sun directly, though together they still do, of course. That said, in the (current) IAU definition, Charon is a satellite of Pluto, not a dwarf planet, so it is Pluto that orbits the Sun directly. The phrase "directly orbiting the Sun" is worded per the IAU definition, whereas "Pluto and Charon are sometimes described as a binary system because the barycenter of their orbits does not lie within either body." only says that sometimes people consider it a binary. Without the word "sometimes" they would contradict each other, but they do not really do now, only for the people who actually consider it a binary, but they still live in a world where the majority does not. --JorisvS (talk) 09:04, 7 June 2015 (UTC)

@JorisvS: Thank you. In addition, Jupiter's barycenter with the Sun is above its surface. Jupiter is still a planet and is still "directly orbiting the Sun", isn't it? Obviously, the location of the barycenter alone does not adequately define what qualifies as planet or a moon. --Cheers, Rfassbind -talk 17:41, 8 June 2015 (UTC)

I completely agree with that. What makes the problem with a simple barycenter definition even clearer: The greater the distance from the primary, the less massive the secondary needs to be for the barycenter to be outside the primary, which means that if a not-so-massive object orbits very far from its primary, it is possible for the barycenter to be outside the primary. --JorisvS (talk) 20:20, 8 June 2015 (UTC)

@Rfassbind. The difference with the example of Jupiter you raise is that its direct relationship is still the sun. Just as Pluto and Charon could be said to be orbiting each other, Jupiter is orbiting the sun, even if the sun is orbiting Jupiter to a very very small degree.

@JorisvS, your argument regarding Charon being officially defined as the satellite of Pluto seems valid. Though it still seems strange that it would be defined that way, over-riding the primary definition of what a satellite is if you see what I mean. (And I'm not sure it changes what's meant by 'directly' in of itself, but I'm not going to make a big deal about it. Just raising it for consideration).121.73.221.187 (talk) 14:49, 13 June 2015 (UTC)

The IAU working group's initial definition of planet included Charon for precisely that reason, but it was voted down. I don't know why; perhaps they blanched at the idea of having to explain it to the public over and over and over again. Serendi^podous 15:17, 13 June 2015 (UTC)

@Anon, the simple barycenter definition is flawed: Whether a binary objects is a primary–moon or a double should not depend on their separation. Also, it is not the primary definition of what a satellite is, because only some people use it.--JorisvS (talk) 15:43, 13 June 2015 (UTC)

It's not a matter of an arbitrary definition, there's nothing to be 'flawed', the barycenter is objectively the centre of the orbit by definition; A natural satellite by definition is a body that orbits a primary body such as a planet/dwarf planet/small solar system body. It's not merely a difference in separation, but of what they're actually doing. If you were standing still and I was walking around you (with you slightly leaning towards me as I went around), that's significantly different to if we were both walking in a circle around a particular spot.121.73.221.187 (talk) 11:48, 14 June 2015 (UTC)

The barycenter of a primary–satellite pair is never exactly at the primary's center. The greater the satellite's mass, the farther it is from the primary's center. But also, the greater the separation between the primary and its satellite, the farther the barycenter is from the primary's center. This means that the barycenter can be located outside the primary for a smaller body further from the primary, but not when they would be closer together. This is not something that should factor in whether something is a primary–satellite or a double. --JorisvS (talk) 12:00, 14 June 2015 (UTC)

Also the barycenter of most asteroid moon systems is also outside the primary. Yawn. -- Kheider (talk) 13:35, 14 June 2015 (UTC)

"The barycenter of a primary–satellite pair is never exactly at the primary's center." -And no one said it was, -it's irrelevant to the point, there's an objective difference between two objects revolving around each other and one object orbiting another. If the barycenter is within one that's objectively the one being orbited. The relationship between two objects defines their relationship, that's tautological. Otherwise what's to stop us saying Charon is the Dwarf Planet and Pluto its satellite. What you're asserting has very little to do with the point raised. I.e. the use of the word 'directly' in relation to the word 'orbit'. It doesn't matter if you call Charon a satellite or blancmange. The objective fact of the orbit is what matters. They're spinning around each other in an orbit. No matter what you want to call them. Labels are all well and good, but they don't change what the objects themselves are actually doing.

And Kheider there's absolutely no need for the addition of comments like 'yawn'. -If you read the article you linked you'd see they're also sometimes referred to as binaries, including the MPC's/IAU's terminology being "binary companions" where a binary nature has been established (or even triple component systems). 219.88.68.195 (talk) 00:13, 15 June 2015 (UTC)

And yet that very link calls Charon a satellite... -- Kheider (talk) 01:01, 15 June 2015 (UTC)

Already been over why that's irrelevant to the point being raised, and it wasn't point you were making that I was addressing.219.88.68.195 (talk) 23:00, 15 June 2015 (UTC)

Anon, there is no break, or what you call "objective difference" between orbiting a barycenter inside or outside a primary. Instead, there is a continuum, with all possible separations between the center of the primary and the barycenter equally possible. And what makes Charon the secondary (satellite) regardless of anything is that it is unambiguously less massive than Pluto. "They're spinning around each other in an orbit": That's what all primary–satellite pairs do, just usually to a lesser degree. Whether the barycenter is just above or below the surface of the primary makes no physical difference. --JorisvS (talk) 09:19, 15 June 2015 (UTC)

Of course there's an objective difference between orbiting a barycenter inside or outside of another body. It's literally right there in what you said. Being inside or outside is an objective difference. And it's an objective difference that defines what is being directly orbited. There is a difference between two objects revolving around a point between them, directly orbiting that point, and one circling the other (even if it gives the primary a wobble); As here, those are two different things.

"Instead, there is a continuum, with all possible separations between the center of the primary and the barycenter equally possible."

By that argument you could say the earth is orbiting the Moon, it's just the barycenter is so far outside the body of the primary on this continuum that it's actually inside the Earth. -If 'all possible separations' are the equally possible.

"And what makes Charon the secondary (satellite) regardless of anything is that it is unambiguously less massive than Pluto."

-Again, you're missing the point. This discussion about labels is irrelevant. It doesn't change the fact of what is actually being directly orbited. Though (and again, this isn't the point) that isn't unambiguous as a definition of a satellite; there isn't a definition relating to relative size afaics, everything references the relationship in regard to orbit as the defining property; and it's also why their relationship is often described in terms of being a binary. And I've already accepted that the de facto labeling of Charon as a Satellite. I'm not arguing that at all.219.88.68.195 (talk) 23:00, 15 June 2015 (UTC)

It is different to you, but not to nature. If the barycenter is close to the surface of the primary, changing its density slightly while keeping its mass the same can mean that the barycenter ends up at the other side of the surface of the primary. No meaningful difference to nature, the objects still orbit with the same semi-major axis and orbital period. But I get the feeling that you think you're right and everyone who disagrees with you is wrong, no matter their arguments. Else, you would have simply understood that the satellite/secondary cannot be the more massive of the pair by definition of the words. --JorisvS (talk) 08:32, 16 June 2015 (UTC)

And if it had much less mass the satellite would spin off by itself, and if it had much more they'd crash into each other. Talking about what ifs doesn't change what is. Inside and outside are objectively different, you surely can't argue with that. Making what is being orbited different. If one body is orbiting a point inside another, then it's perfectly straight forward to say it is orbiting that body; If they're both orbiting a point outside of themselves, between them, that's not so straight forward. -Again, the definition of the words rely on the relationship of the orbit in regard to one another. I understand why that means the more massive of the two will be the primary; I was using the example to point out why your argument about a 'continuum' with "all possible separations between the center of the primary and the barycenter equally possible" was flawed.

And more to the point, this is still on the point about labels. -It's irrelevant to the point that's been raised about the use of the word 'directly'.121.73.221.187 (talk) 10:58, 16 June 2015 (UTC)

My point of the example is that there are no physical breaks anywhere that can non-arbitrarily be used in a definition. When looking from afar, the primary will be seen to wobble with respect to the background whether the barycenter is just inside or outside, and the degree to which it does will be virtually the same in those two cases. The simple barycenter definition depends positively on the density of the primary and the semi-major axis of the secondary, which are rather weird parameters to factor into what is a double or isn't. You can disregard this, but it won't get you anywhere. --JorisvS (talk) 11:50, 16 June 2015 (UTC)

How is being inside or outside not a non-arbitrarily physical break. -It doesn't matter how that hypothetical situation looks from a distance, we know it's outside in the case of Pluto and Charon. The IAU take the idea seriously and have explicitly stated that reclassifying Charon as a Dwarf planet may be considered. -Even explicitly saying they orbit each other (see 'Is Pluto's satellite Charon a dwarf planet?' here (and that constitutes an WP:RS)) -which is the point I'm raising about the world 'directly'; they cite their comparable size, and refer to the barycentre residing in the free space between them.

-Binary star systems exist with different size stars. The larger is just labeled the primary and the smaller a companion. That doesn't mean they're not in a binary relationship. Density/axis aren't weird parameters; the definition of what constitutes a binary relates to the relationship of the orbit. But -not that it matters, because again, it doesn't matter what we label them, -the point being raised is what they're actually doing in terms of what each is directly orbiting. -And we know they orbit each other -there's a reliable source right there. I'm not questioning the de facto present labeling at all.219.88.68.195 (talk) 21:52, 16 June 2015 (UTC)

Back to the original question - yes, Pluto directly orbits the sun. If Charon were reclassified as a dwarf plant, Pluto would still directly orbit the sun, with Charon. In your binary star analogy, if a star were, say orbiting a super-massive black hole, it would be doing so directly whether or not it had a binary companion. VQuakr (talk) 00:38, 17 June 2015 (UTC)

Thank you for addressing the actual question. But why is that 'directly' when you wouldn't say a moon was directly orbiting the sun? In both cases they're orbiting something else which is closer, while still going round the sun. What's the distinction? I can see how you could say the binary system was orbiting the sun, but they're individually speaking directly orbiting each other, as much as a moon orbits its primary. Like you could say the Moon and the earth orbit the sun together, but if you were talking about the Moon individually you'd say its direct orbit was around the earth. If you see what I mean.219.88.68.195 (talk) 04:06, 17 June 2015 (UTC)

The Earth/Moon comparison is not exactly accurate. In the case of the Moon, although it is directly orbiting the Earth its orbit is also at all point concave to the Sun and so it could just as accurately be said to be directly orbiting the Sun. I do not think this is the case with the Pluto/Charon system.EJM Missouri (talk) 17:06, 23 June 2015 (UTC)

We're not supposed to re-argue all the screwy philosophy decisions people make when drawing lines in astronomy. As long as the source supports the statement, we print it. Get another source with a contradictory statement, we print that too. The article is allowed to contradict itself; it's not allowed to contradict its sources. Wnt (talk) 01:09, 14 July 2015 (UTC)

Which makes perfect sense, however just to point out, only the second assertion concerning the barycenter is cited, the first concerning it directly orbiting the sun is not.121.73.221.187 (talk) 08:53, 24 July 2015 (UTC)

Pluto curves away from Sol while Luna never curves away from Sol. Hcobb (talk) 22:01, 24 July 2015 (UTC)

NASA-TV - New Horizons results - News Conference (2pm/et/usa, Friday, 7/24/2015)

NASA-TV - New Horizons results - re Pluto flyby - News Conference (2pm/et/usa, Friday, 7/24/2015) - in any case - Enjoy! :) Drbogdan (talk) 12:33, 22 July 2015 (UTC)

BRIEF Followup - Video (68:40) of NASA media conference (2pm/et/usa - 7/24/2015), with the latest images of the Pluto system from New Horizons, is at => VIDEO & IMAGES - in any case - Enjoy! :) Drbogdan (talk) 15:05, 25 July 2015 (UTC)

References

Question about infobox image size...

Why in the world is it so much larger than the vast majority of infobox images for solar system objects (260-280px)? Philip Terry Graham 04:44, 25 July 2015 (UTC)

The planet (and dwarf planet) infobox images tend to be larger. Earth's is 300px. Rreagan007 (talk) 07:41, 25 July 2015 (UTC)

Is there any ruling of some sort that the infobox images be a particular size? Earth seems to be another odd-one-out as well. Mercury (planet), Venus, Mars, Jupiter, Uranus and Neptune, in addition to Ceres (dwarf planet), Eris (dwarf planet) and Makemake are all 260px, while Saturn is 280px, since the rings are accountable. Your comment that they "tend to be larger" seems to be very wrong. >.> Philip Terry Graham 10:29, 25 July 2015 (UTC)

I really don't consider 20px to be "so much larger", but there is no one standard for image size in infoboxes. And there are certainly other infobox images for celestial bodies that are larger. I think one reason a lot of bodies have smaller images is because the quality of the image is a lot less. But when you have a high quality image, there is a natural inclination to want to show it off. Just looking through a few, the Moon is 292px, the Sun is 300px, Europa is at 275px, and 4 Vesta is at 300px. Personally, I like having a larger image in the infobox when there is a high quality image available. Rreagan007 (talk) 17:23, 25 July 2015 (UTC)

When should we start adding new information?

Should we use the press conferences as sources, or should we wait until the scientific papers come out? Serendi^podous 21:50, 25 July 2015 (UTC)

I see no problem with such a reference. However, if you're referencing videos of press conferences, please time-index the video. Don't reference, say, a 60-minute press conference, without saying that what supports the text occurs, say, at 20 minutes in (and there are parameters for just that, in the cite AV media template). Dhtwiki (talk) 22:46, 25 July 2015 (UTC)

I agree. For now we can use those videos and press conferences. This is the only way to quickly start presenting New Horizons' findings. When papers become available, they should replace those cites, of course. --JorisvS (talk) 08:43, 26 July 2015 (UTC)

I agree as well. Until published sources become available, the press conference videos should be used as sources to keep the article as up to date as possible. I also agree that when sourcing a video, you should timestamp the location of the information cited and, if possible, the name of the person speaking. Rreagan007 (talk) 17:49, 26 July 2015 (UTC)

Captain Future and the moons of Pluto

Calling Captain Future was the second of the Captain Future pulps and was published in Spring 1940, about a young hero and his three inhuman companions who travel the Solar System and beyond, righting wrongs. In that pulp book, he travels to Pluto. Pluto has three moons: Charon, Cerebus and Styx, with Charon being the largest. What an amazing coincidence.(80.30.191.121 (talk) 17:27, 30 July 2015 (UTC))

It's not a coincidence. The names weren't pulled out of a hat, neither by the pulp writer or by astronomers. They were taken from Pluto-related Roman mythology.

This factoid should probably be added to Pluto in fiction. Choor monster (talk) 18:39, 30 July 2015 (UTC)

Binary nature

The binary dwarf planets category fits - Most sources say that Pluto and Charon are a binary system.

The barycenter is outside either body, making Charon also a dwarf planet.

Apologies for breaking 3RR, but the category should stay. DN-boards1 (talk) 19:47, 27 August 2015 (UTC)

The barycentre criteria is not that widely accepted. Charon was listed as a DP in the draft IAU proposal, but was removed in the final because there were too many objections to that criterium. Notably, it would mean Jupiter is not a planet, since the Sun-Jupiter barycentre is without the Sun. Tbayboy (talk) 19:55, 27 August 2015 (UTC)

"Most sources"? The sources cited both on Pluto and on Charon say Charon is not a dwarf planet (though of course all say Pluto-Charon is a binary system). —Alex (Ashill | talk | contribs) 19:57, 27 August 2015 (UTC)

The barycenter criteria is only for dwarf planets. The ratio of mass is not the same, either. Charon is more than HALF the size of Pluto, and larger than Ceres. And Charon doesn't orbit Pluto. A moon orbits a planet, small Solar System body, or dwarf planet - Charon and Pluto orbit one another. DN-boards1 (talk) 20:01, 27 August 2015 (UTC)

Any sources say this? The cited ones don't. —Alex (Ashill | talk | contribs) 20:04, 27 August 2015 (UTC)

We might acknowledge that scientists sometimes label things within a given paper in order to facilitate the communication of certain points relevant for that paper. Or they might label things in a certain way hoping to make a more general point that they think applies outside of the paper as well. This may or may not apply to this particular discussion of Pluto and Charon. But we might also acknowledge that calling a planet and its moon a "double planet" because its barycenter happens to be outside of the surface of the larger body is something of an arbitrary distinction if it doesn't actually have some other related importance. Isambard Kingdom (talk) 20:15, 27 August 2015 (UTC)

• DN: You don't get to edit war, even if you're "right". Fundamentally, both sides have good arguments, and both sides can point to sources that suggest their view is correct. We use Talk to make our cases, consensus will emerge, and it will stay that way until the Real World changes its mind. Choor monster (talk) 20:59, 27 August 2015 (UTC)

I'd say the category fits -- we have significant RS's that Pluto-Charon are a double DP, and it doesn't matter that the classification is not followed by the IAU. But it's silly to have a category for a single case. — kwami (talk) 21:59, 27 August 2015 (UTC)

Images for the infobox

• 
  Coloured
• 
  Not coloured

The colouration of the LORRI images degrades the contrast of the image (check the comparison on the right). Although the colour information provided by MVIC is valuable and relevant for the infobox, it is of a much lower resolution than the brightness and shape information provided by LORRI. I don't think they look particularly pretty, either, and since they sort of reduce the actual resolution of the image, I don't think we should have coloured LORRI images for the infobox.

According to this information, a colour image of Pluto from MVIC (i.e. a "real" colour image) where Pluto will be 480 pixels across will be downlinked on 16 July. This might be usable for the infobox. Other than that, we will have to wait until September for better colour images from MVIC.

We'll also probably soon (like tomorrow) be at a stage where raw images will likely be the best images for the infobox, by the way. --Njardarlogar (talk) 11:07, 7 July 2015 (UTC)

Of course this whole discussion will be completely moot in just over a week. However, in the meantime a color image reflects what Pluto is like much better than a greyscale image, even if it is of a somewhat lower resolution. --JorisvS (talk) 11:52, 7 July 2015 (UTC)

As per what I wrote above, due to the downlinking schedule, this debate can be relevant all the way until September, October or even later. :-) In terms of downlinked data, most of the flyby happens in September and the following weeks/months, not next week. --Njardarlogar (talk) 12:14, 7 July 2015 (UTC)

Again we are having some issues. The highest-resolution image released to date, is the image from 8 July, not 7 July. One must not confuse the resolution of the image file and the spatial resolution of the image. It's easy to blow up the 8 July, should that be preferable, but it is, either way, the best image we got of Pluto at this point. --Njardarlogar (talk) 12:48, 10 July 2015 (UTC)

Why don't we just use the color image until we get the final full frame pictures and then use that? This is all about esthetics after all, and the color one looks cooler. Cool trumps all. We have a few days to think about it....Ericl (talk) 12:28, 11 July 2015 (UTC)

I am not sure which images you are referring to now, the image we currently have for the infobox is positively the coolest picture planetary science has produced for quite some time (and we have no colour version of it). --Njardarlogar (talk) 12:47, 11 July 2015 (UTC)

I am beside myself with excitement. We are seeing things no person has ever seen before. History before our very eyes (and constantly updating on Wikipedia!). Anyway, I vote monochrome for now :)82.71.30.178 (talk) 22:03, 12 July 2015 (UTC)

Currently, right beneath that (awesome) image in the infobox, we see the caption "Colorized image[1] of Pluto taken by New Horizons spacecraft on 13 July 2015", quoting an article from MSNBC. Yet, in a public AMA with the scientists of the New Horizons team on the popular link aggregation website Reddit, we have first hand sources/direct comments from scientists Jillian Redfern and Kelsi Singer stating that the image is "true color" and not altered or enhanced. Should we consider modifying the caption in the infobox to reflect that this is not a colorized image? Relevant source links:

• Reddit AMA: http://www.reddit.com/r/IAmA/comments/3d9luh/were_scientists_on_the_nasa_new_horizons_team/ct317b9
• New Horizon's Team: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150712 — Preceding unsigned comment added by 50.170.29.199 (talk) 06:23, 15 July 2015 (UTC)

New Wikipedia user here. I spent a few hours combining LORRI images from the latest release into a 3k by 3k panorama. Might make a good featured image: https://commons.wikimedia.org/wiki/File:Pluto_via_New_Horizons_(composite).jpeg

The Verge has a similar composite, but theirs is a simple copy-paste job with obvious seams: https://www.theverge.com/tldr/2015/9/12/9313591/new-horizons-pluto-high-resolution Hjhornbeck (talk) 17:18, 12 September 2015 (UTC)

Feel free to pop it in the gallery for now, if nothing else. A2soup (talk) 19:06, 12 September 2015 (UTC)

I'd love to, but I'm so new that I can't edit semi-protected pages at the moment. Hence why I'm on the Talk page instead. Hjhornbeck (talk) 16:53, 13 September 2015 (UTC)

Higher-Res image

I found a higher resolution image at this source: http://planetary.s3.amazonaws.com/assets/20150714_pluto-nh-ehealth1.png Linked from Emily Lakdawalla's Twitter feed.

Here is the post it is from: http://www.planetary.org/multimedia/space-images/small-bodies/pluto-20150713.html

The new image has a resolution of 1024x1024, improved over the current resolution of 299x299 Arithmaldor (talk) 13:37, 14 July 2015 (UTC)

Working on getting the original image updated (it has become protected). Your comparison of resolution is wrong, though; the current image is cropped (as is the replacement). The first instragram release was close to full resolution. --Njardarlogar (talk) 13:55, 14 July 2015 (UTC)

Uploaded image to Commons => File:NH-Pluto-color-NewHorizons-20150714.png - [update notes: Drbogdan (talk) 14:45, 14 July 2015 (UTC) => uploaded 1024x1024/405KB version - then cropped to 646x646/383KB-PNG - possibly better resolution than the earlier 700x700/245KB-JPG version?] - hope this helps in some way - iac - Enjoy! :) Drbogdan (talk) 14:00, 14 July 2015 (UTC)

The original has now been updated to full resolution. --Njardarlogar (talk) 14:04, 14 July 2015 (UTC)

For anyone wondering, here is the 'raw image' that the release is based on. Any version of the image where Pluto appears larger than here has been blown up, much or just like anyone can do at home. --Njardarlogar (talk) 17:11, 15 July 2015 (UTC)

Or has been composited together with panorama software, eg. my own contribution. https://commons.wikimedia.org/wiki/File:Pluto_via_New_Horizons_%28composite%29.jpeg . A third approach is to use photogammetry software to map all the images onto a sphere, then render that sphere; you don't get the surface feature shifts that you see with the panorama approach, yet you keep the advantage of splicing together multiple images. So far, I haven't seen any attempt at this third method. Hjhornbeck (talk) 18:19, 13 September 2015 (UTC)

Correction: The scientists at NASA/John Hopkins are using the photogammetry method, but I still haven't seen any amateurs attempting the same. See the first image here: https://www.nasa.gov/feature/new-pluto-images-from-nasa-s-new-horizons-it-s-complicated Hjhornbeck (talk) 00:20, 14 September 2015 (UTC)

Unofficial names of Pluto features

I would like to recommend that we be wary of the current situation concerning the IAU/New Horizons Relationship. Some of the wording (such as the annotated projection of Pluto's surface), do not make it clear that all of these names remain not only unofficial but submitted to the official planetary naming body--the IAU. As such the names remain unofficial and many would seem to have little hope to become official due to their inconsistency with the IAU's planned themes for the planet. Currently, the truthful approach is simply to consider all of the names to be provisional.130.118.160.220 (talk) 16:07, 14 September 2015 (UTC)

What's the problem? We can change the names if and when the IAU approves different names for those features. --JorisvS (talk) 17:38, 14 September 2015 (UTC)

This seems like a potential problem, to me. Can the IP (or anybody) give an example of where Wikipedia is listing a feature on Pluto with a name this likely not to be accepted by IAU? The issue brought up by the IP is similar the larger problem that exists at Wikipedia, where information gets entered into articles, and it often stays there united and unverified, but readers often assuming that it is correct. This is why we are supposed to cite reliable sources. Isambard Kingdom (talk) 17:52, 14 September 2015 (UTC)

Main image vandalized

Why false color image there??? The main image should show the REAL COLOR IMAGE like it did before. Resolution alone shouldn't whore the main image on a featured article. — Preceding unsigned comment added by 62.57.11.157 (talk)

 Reverted. The infobox image should be a true-color image, obviously. --JorisvS (talk) 23:15, 26 September 2015 (UTC)

Thank you! Appreciated! 62.57.11.157 (talk) 16:40, 27 September 2015 (UTC)

Surface, volume precision

The latest mean radius is 1186±2 km (based on the press conference). Should we not display the precision for the surface and volume? Darkdadaah (talk) 09:48, 31 July 2015 (UTC)

We have a better estimate for the mean radius of Pluto at 1187±4 km from the new paper in Science From these new Surface Area, Volume figures are derived. The Density figure given 1860 ± 13 kg m^(-3) is consistent with the Mass and Volume.Rudy235 (talk) 22:29, 15 October 2015 (UTC)

@JorisvS Can you please edit reference 6 Mass was calculated fron actualized value of GM Pluto and constant G=6.67259 x 10^-11 (general accepted value) I am at a loss of how to correct reference #6 (Mass)Rudy235 (talk) 00:19, 16 October 2015 (UTC)

Density

The source lists 1,879 kg/m³, but without any uncertainty. Simply doing the math with the mass and the radius, gives a density of 1.867±0.020 g/cm³. The uncertainty is, as I expected, large enough to make giving that much precision meaningless. But, unexpectedly, the mean value is also different from the sourced value! Looking at the source, this is simply due to both rounding in the mass they use, as well as using a radius of 1185 km. First of all, listing that much precision is bullshit. Secondly, the radius in the infobox, 1186±2 km, is a value determined a bit later than the 1185 km, and hence can be expected to be more accurate, especially given that it includes error bars. Moreover, the mass listed is a more precise value. Therefore, a simple calculation yields a more accurate and consistent density value. --JorisvS (talk) 10:00, 27 September 2015 (UTC)

OK, thanks for clearing that up! Double sharp (talk) 14:05, 27 September 2015 (UTC)

Newer studies The Pluto system: Initial results from its exploration by New Horizons give a more acurate value of the density. I cross referenced it with the new mean Radius and new Mass (obtained from the stated value of GMpluto) and it is the same: 1,860kg/m³± 13 Rudy235 (talk) 02:05, 16 October 2015 (UTC)

Different moon rotation and surface

New horizon has found new things on Pluto, and group of scientists in university of Maryland and Pluto experts yet have proven ice on the surface and the other expert has proven the unique rotation of its moon. Read the complete story on the link: [3] MansourJE (talk) 06.12, 17 October 2015 (UTC)

That seems to be worth taking a look. Huritisho 06:05, 17 October 2015 (UTC)

Dates

If this article is written in American English, it seems like it should also use mdy dates. Is there a good reason for why it has dmy dates? Tad Lincoln (talk) 02:11, 22 October 2015 (UTC)

That's a good question. I checked the source of the article and found this template {{Use dmy dates|date = May 2015}}, so the template was added not that long ago, even though of course the dmy dates have in the article for much longer. I suggest we change all the dates. I'll change them myself for now and if anyone disagrees, they can just revert me Perhaps I should wait to see what others think. If the article uses dmy, there might be a reason for it Huritisho 02:19, 22 October 2015 (UTC)

mdy would be correct given that is what the article used years ago. -- Kheider (talk) 02:45, 22 October 2015 (UTC)

@Kheider: It has to be either american on british english. It doesn't make sense to have a mix of both. Huritisho 03:13, 22 October 2015 (UTC)

Since one else gave their opinion on this, so I'll go change the dates. If anyone disagrees, revert me and come discuss. Cheers, It is going to be harder than I thought. There are too many dates to change... Huritisho 07:10, 23 October 2015 (UTC)

References

3D Image of Pluto - Possible Add?

A new 3D image of Pluto (see below) was released October 23, 2015 - should this image be added to the Pluto article (and/or some other article?) - Comments Welcome - Enjoy! :) Drbogdan (talk) 01:40, 24 October 2015 (UTC)

Pluto - 3D image
(released October 23, 2015)

More Nasa Horizon images

File:HT pluto new horizon mm 150925 31x13 1600.jpg

A high resolution image of its surface by Nasa's Horizon satellite

File:Snakeskin detail.png

A closeup of its Hades region appears to have a snakeskin surface

— Preceding unsigned comment added by 69.255.27.70 (talk) 15:47, 25 October 2015 (UTC)

Found a High-Res Near True Color Image of Pluto

I found a 8000x8000 near true color image of Pluto posted by HarbingerDawn in a Space Engine forum post. Here's the link to this post.

http://en.spaceengine.org/forum/22-758-10

76.103.8.112 (talk) 22:04, 28 October 2015 (UTC)

Precision significant figures

Let's try a primer on Significant Figures.

In a division, if both quantities are known with 4 significant figures, then the quotient also has 4 significant figures. If a Mean radius has an error bar of Radius for Pluto in km =1187 ±4, then volume is --in 10^9 units-- 7.006±0.071.

This is because the error on the Radius is ± 0.337%, then the Error in the Volume is ~ 3 times 0.337% or 1.01% (π is known with about 1 billion digits, so it does not introduce any error.) However that does not mean that the last digit is spurious precision.

Example: the Constant G is cited as we obtain the value G = 6.67191(99) × 10(-11) m(3) kg(-1) s(-2) with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology.

So, the uncertainty is 0.015% or ~ 0.001 x 10(-11) m(3) kg(-1) s(-2)

However it is NOT published as 6.671± 0.001 http://www.livescience.com/46385-new-gravitational-constant-measurement.html

So, we should not confuse uncertainty with precision. There is nothing wrong with quoting 7.006 ± 0.071; it means that the value (with about 95% of confidence) is between 6.935 and 7.077.

More information here: https://en.wikipedia.org/wiki/Accuracy_and_precisionRudy235 (talk) 05:05, 16 October 2015 (UTC)

Yes, the rounding should not add any extra imprecision to the combined value and error margin. 1.17 ± 0.05 ≠ 1.2 ± 0.05 ≠ 1.2 ± 0.1 Btljs (talk) 05:36, 16 October 2015 (UTC)

For instance look at the GM value for Nix is 0.0030 ± 0.0027 (km^3 s^-2)

Nix 48,690 24.8548 0.00000 0.0 54 × 41 × 36‡ 0.0030 ± 0.0027

http://www.sciencemag.org/content/350/6258/aad1815/T1.expansion.html

This does NOT mean that the correct way of expressing this is 0.00.

It is true that the value can be as little as 0.0003 and as big as 0.0067.

But is ±0.0027 spurious precision? The answer is no!

See.. Stern et al., 350 (6258): > Table 1 ::http://www.sciencemag.org/content/350/6258/aad1815/T1.expansion.html Rudy235 (talk) 06:30, 16 October 2015 (UTC)

All I can say is that I do hope the information you're adding is correct. Huritisho 16:09, 16 October 2015 (UTC)

All the information is as correct as the source is. The source is a paper recently published in sciencemag.org Science 16 October 2015:

Vol. 350 no. 6258

DOI: 10.1126/science.aad1815

Just calculate it: What's the volume for a radius of 1191 km and 1183 km? Which figures change and which don't? Giving figures that can be completely different gives a false impression of precision. At least if the uncertainty is included explicitly, this false impression does not exist. --JorisvS (talk) 17:28, 16 October 2015 (UTC)

That calculation I already did before I even made the changes; it is as follows: Radius 1191 volume =7076587708.30445 X 10 ^9 m^3. However, only 4 significant figures can be used as the original info has 4 significant figures; so, it becomes 707,700,000 X 10^9 m^3. Likewise, Radius 1183 gives 6934942159.03415 x 10^9 m^3 but with 4 significant figures, it should be expressed as 693,500,000 X 10^9 m^3. The information correctly expressed is: 7.006 ± 0.071 X 10^17 m3. That is how it's done. Unless, of course, you believe that Alan Stern and the about 140 authors of the paper mistakenly stated the the GM Nix was 0.030 ± 0.027 km^3 s^-2 and should have simply said that it was 0.0 km^3 s^-2. It is not rocket science. You carry as many significant figures as the least reliable info. For instance, if you have a radius of 1.0m, then the area of the circle is 3.1 m^2; if you have an area of 1.000m, then the area is 3.142 m^2

Finally is you are adding to quatitities for instance 7.321 m + 1 m the result can (should) only carry 1 significant figure as that is what we have on the least precise of the addends. The correct result is thusly 8m. Rudy235 (talk) 19:56, 16 October 2015 (UTC)

As I said, it's different with an uncertainty. Without it, it's like giving 8.3m in your example.--JorisvS (talk) 12:16, 18 October 2015 (UTC)

The rule of keeping the same number of significant figures as the least reliable or given with the fewest significant figures is flawed. It also matters what is done with the number. A sphere with a stated radius of 1191 km could have a volume between 7,067,678,870 and 7,085,504,029 km^3. The most precise expression would be 7,100,000,000 km^3. Also, the number of figures is not all. 9.999 is about an order of magnitude greater that 1. Saros136 (talk) 04:09, 29 October 2015 (UTC)

Official naming

Despite of reading quite a lot sources about history of Pluto's discovery, I can't find anywhere that "The object was officially named on March 24, 1930". This was inserted in 2007 by an IP (without any sources), both sources, which now hang on this phrase, are inaccessible, and the given quote from the second of them does not confirm this statement. Actually the name "Pluto" was officially proposed by Lowell Observatory 1 May 1930, and the second given source (also cited here) say about some announcing on May 25, but not March 24. Moreover, it would be very strange if newspapers wrote about some event 2 months after it. So, it's very probable that the statement about March 24 is a vandalism or mistake. I want to ask users with access to old numbers of The Times and The New York Times to check this info. Stas (talk) 00:26, 26 November 2015 (UTC)

Good idea for now. If someone wants to pay to look up the online archives, that would be great. Serendi^podous 05:56, 26 November 2015 (UTC)

I do not mean "pay yourself, because I don't want". Maybe, somebody is a subscriber. Stas (talk) 10:58, 26 November 2015 (UTC)

Mean Elements and TOP2013

I'm excited that there are now analytic theories of planetary motion that include Pluto, and there are online elements for the solutions of TOP2013, the Theory of the Outer Planets by the Institut de mécanique céleste et de calcul des éphémérides (IMCCE) along with VSOP2013. the abstract is here.

The elements are in radians for angles and the numbers in general are in a less familiar format. So I made a spreadsheetwith elements and other figures derived from them, and in degrees and julian days and years, online. Saros136 (talk) 10:41, 27 November 2015 (UTC)

Semi-protected edit request on 2 December 2015

The Photo for Pluto is not accurate. This is a true colour image of the Dwarf Planet http://pluto.jhuapl.edu/Multimedia/Science-Photos/pics/nh-pluto-in-true-color.jpg . The image currently there has its colours exxagerated so scientist would have a better view of the very subtle colour shifts of each area of the planet. Please change the imge 99.234.208.53 (talk) 21:12, 2 December 2015 (UTC)

Thanks. Seems we're going to be whack-a-mole-ing that for the foreseeable future; for some reason, some people think hi-def is preferable to reality. Serendi^podous 22:08, 2 December 2015 (UTC)

Atmosphere of Pluto

The article (and corresponding section in the main article) seems to have serious problems. Maybe, somebody would be interested in rewriting. Stas (talk) 23:27, 8 December 2015 (UTC)

Well, be bold and go ahead with rewriting it. ♆ CUSH ♆ 17:08, 9 December 2015 (UTC)

Image

Hi, @JorisvS: File:Pluton, par la sonde spatiale New Horizons, le 14 juillet 2015.jpg is obviously much better. Could you explain why you reverted me? Thanks, Yann (talk) 10:08, 27 September 2015 (UTC)

Look at it. Those colors are not what it looks like. It may be of higher resolution, but it is misleading because Pluto does not look like that. Whenever available, the infobox image should be a true-color image. --JorisvS (talk) 10:13, 27 September 2015 (UTC)

The current image is also a composite. Higher resolution beats blurry images any day. The details in the higher resolution image are photographic, only the color has been enhanced. Visitors want to see surface features. ♆ CUSH ♆ 17:41, 3 October 2015 (UTC)

No, visitors want to see what Pluto looks like. That is not what Pluto looks like. Serendi^podous 17:48, 3 October 2015 (UTC)

The present image does not show what Pluto looks like either. So what is your point? Also, the background has been removed in that image. ♆ CUSH ♆ 18:18, 3 October 2015 (UTC)

 Done - earlier edit rv - *entirely* agree with User:JorisvS and User:Serendipodous - original image is better - and preferred - in any case - Enjoy! :) Drbogdan (talk) 18:23, 3 October 2015 (UTC)

That is a doctored, composite image. The surface structure and color come from different cameras. Please stop forcing this crap. 18:27, 3 October 2015 (UTC)

"The surface structure and color come from different cameras" This is true of every modern NASA image. It is also true for many iconic images of the Eagle Nebula, Pillars of Creation, etc, that are among the most interesting images on Wikipedia. Practically all modern photography involves some level of post-production color balancing, including all modern smartphone images. Don't be a luddite. Curedwales (talk) 06:30, 4 October 2015 (UTC)

So, between two images that both do not show what Pluto looks like visually, why go for the one of lower quality? We are here to educate people, so the higher resolution image should be preferred. Anyone with interest in astronomy wants to see details. Even a grey-scale image would be better than the current one. ♆ CUSH ♆ 10:43, 4 October 2015 (UTC)

It does show what Pluto looks like, as faithfully as was possible with New Horizons' instruments. And people don't just want to see greyscale topographical details, but also colors. --JorisvS (talk) 11:00, 4 October 2015 (UTC)

People with only a superficial interest maybe. And btw, the high resolution image is not without color. ♆ CUSH ♆ 17:46, 7 October 2015 (UTC)

Images should be for the general public. Most people don't care about details. Huritisho 17:50, 7 October 2015 (UTC)

People who look up Pluto do. In some countries the "general public" is somewhat more interested in details than in other counties. Want me to hint at stereotypes about some countries' general public? This is an international encyclopedia existing to educate people about details. ♆ CUSH ♆ 17:43, 8 October 2015 (UTC)

@Cush: Perhaps both POVs re images can be accomodated to some extent - I've added your "favored image" to the "other versions" section of the "original image" description - hope this helps in some way - iac - Enjoy! :) Drbogdan (talk) 18:14, 8 October 2015 (UTC)

So, almost half a year after the flyby, is there any better image than the fake in the info box at the top of the page? ♆ CUSH ♆ 09:37, 11 December 2015 (UTC)

Semi-Major Axis

This article lists Pluto's Semi Major Axis as equal to 39.54 AU. But the sum of the listed Perihelion + Aphelion divided by two is equal to 39.49. Why is there a discrepency, or are the measurements really only known to three significant figures?Inkan1969 (talk) 20:46, 8 December 2015 (UTC)

The numbers do seem inconsistent. The perihelion and aphelion should be a*(1 +/- e), so their average should be the same as a as you say. Tom Ruen (talk) 10:32, 11 December 2015 (UTC)

There is no mistake here. In the textbook ellipse, the semimajor axis is perihelion + aphelion divided by two. The actual orbits are not perfect ellipses. In fact the extreme distances always change. So do the mean elements. Saros136 (talk) 16:57, 25 December 2015 (UTC)

NASA Briefings/livestream (March 21 – 22, 2016) – Ceres, Mars, Pluto Results.

NASA Briefings/livestream – Experts to discuss the latest Ceres, Mars, Pluto results (near Houston, TX; March 21 – 22, 2016) - Enjoy! :) Drbogdan (talk) 12:34, 17 March 2016 (UTC)

Followup - studies re Pluto - in any case - Enjoy! :) Drbogdan (talk) 13:36, 18 March 2016 (UTC)

References

Shouldn't origin be under history?

Why is the origin section not under the history section? --UnindentifiedHuman (talk) 07:13, 25 March 2016 (UTC)

Because it's only half historical, and the history isn't about Pluto; it's about the Kuiper belt. Serendi^podous 07:25, 25 March 2016 (UTC)

The section titled 'planet x disproved' should be changed given current events

As it wasn't 'yet' proven, however there have been changes today.

e.g. http://www.independent.co.uk/news/science/planet-nine-scientists-find-more-evidence-that-hidden-planet-is-sitting-at-the-edge-of-our-solar-a6954986.html — Preceding unsigned comment added by 90.193.237.212 (talk) 13:46, 28 March 2016 (UTC)

Not the same planet. It's called "Planet Nine". Serendi^podous 15:09, 28 March 2016 (UTC)

Carload of new info on Pluto's atmosphere

Not sure how much should go in here and how much in Atmosphere of Pluto Serendi^podous 12:51, 29 March 2016 (UTC)

External links modified

Hello fellow Wikipedians,

I have just modified one external link on Pluto. 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:

• Corrected formatting/usage for http://www2.lowell.edu/~grundy/abstracts/preprints/2013.Pluto_SpeX.pdf

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

Y An editor has reviewed this edit and fixed any errors that were found.

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.
• http://www2.lowell.edu/~grundy/abstracts/preprints/2013.Pluto_SpeX.pdf [working, non-archival]
• https://web.archive.org/web/20151108210124/http://www2.lowell.edu/~grundy/abstracts/preprints/2013.Pluto_SpeX.pdf [working, archival]

Cheers.—^{cyberbot II}_{Talk to my owner:Online} 17:09, 1 April 2016 (UTC)

Both links work. No need to mark URL as dead, yet. Dhtwiki (talk) 23:12, 2 April 2016 (UTC)

Edit request: come into question

Currently the lead says: "After 1992, its status as a planet fell into question". Please correct this as follows: "After 1992, its status as a planet came into question". Alternatively, "was called into question". — Preceding unsigned comment added by 86.154.102.78 (talk) 20:51, 6 May 2016 (UTC)

 Half done. That sentence could indeed be improved, but there are other ways to improve it further. For one, there is the verb "to question". Also, it issn't a status issue per se, but a scientific question about what the nature of Pluto within the Solar System (i.e. planethood). --JorisvS (talk) 09:08, 7 May 2016 (UTC)

Quasi-satellite disproven

I updated the "Quasi-satellite" section to indicate that the quasi-satellite hypothesis has now been disproven by New Horizons. Since the whole thing turns out to have been wrong, perhaps it should be removed altogether now. StormWillLaugh (talk) 11:15, 5 June 2016 (UTC)

@StormWillLaugh: According to the (15810) 1994 JR1 article, it is once again considered a quasi-satellite. I have no idea which assessment is correct, however. Kaldari (talk) 02:47, 29 August 2016 (UTC)