:Not officially yet. Oh, and as far as Plutodolia is concerned, I'm more partial to [https://pbs.twimg.com/media/CJ9vZCbVEAAFxrt.jpg:large this idea]. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 19:44, 15 July 2015 (UTC)
:Not officially yet. Oh, and as far as Plutodolia is concerned, I'm more partial to [https://pbs.twimg.com/media/CJ9vZCbVEAAFxrt.jpg:large this idea]. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 19:44, 15 July 2015 (UTC)
== Rotation and the north pole==
== 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?[[Special:Contributions/188.69.214.120|188.69.214.120]] ([[User talk:188.69.214.120|talk]]) 07:48, 12 July 2015 (UTC)
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?[[Special:Contributions/188.69.214.120|188.69.214.120]] ([[User talk: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) --[[User:JorisvS|JorisvS]] ([[User talk:JorisvS|talk]]) 09:32, 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) --[[User:JorisvS|JorisvS]] ([[User talk:JorisvS|talk]]) 09:32, 12 July 2015 (UTC)
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::::Australians (and others in the southern hemisphere), I think, see north pole up, as they do see the Moon upside down.[[Special:Contributions/188.69.214.120|188.69.214.120]] ([[User talk:188.69.214.120|talk]]) 11:45, 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.[[Special:Contributions/188.69.214.120|188.69.214.120]] ([[User talk: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? [[User:Wnt|Wnt]] ([[User talk:Wnt|talk]]) 16:44, 13 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? [[User:Wnt|Wnt]] ([[User talk: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). [[User:Jeffryfisher|Jeffryfisher]] ([[User talk:Jeffryfisher|talk]]) 21:03, 19 July 2015 (UTC)
This article is not the place to discuss or complain about Pluto's reclassification as a dwarf planet, to suggest alternative definitions, or to compose new mnemonics. Wikipedia is not a forum. Unless a complaint relates specifically to improving this article, it should be left off the talk page. If you have a question about Pluto's reclassification, please see the articles Definition of planet and 2006 definition of planet, or ask at the Reference desk.
This article is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.AstronomyWikipedia:WikiProject AstronomyTemplate:WikiProject AstronomyAstronomy articles
This article is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.AstronomyWikipedia:WikiProject AstronomyTemplate:WikiProject AstronomyAstronomy articles
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)[reply]
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)[reply]
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)[reply]
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).
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)[reply]
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)[reply]
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?
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. Serendipodous08:20, 4 June 2015 (UTC)[reply]
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.
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
@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-talk17:41, 8 June 2015 (UTC)[reply]
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)[reply]
@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)[reply]
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. Serendipodous15:17, 13 June 2015 (UTC)[reply]
@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)[reply]
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)[reply]
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)[reply]
"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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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. Serendipodous17:54, 18 June 2015 (UTC)[reply]
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)[reply]
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. Serendipodous18:07, 25 June 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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:
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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. Serendipodous20:13, 13 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
Semi-protected edit request on 13 July 2015
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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. Serendipodous00:49, 14 July 2015 (UTC)[reply]
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)[reply]
(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)[reply]
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)[reply]
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. Serendipodous02:19, 14 July 2015 (UTC)[reply]
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)[reply]
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? Serendipodous02:31, 14 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
Semi-protected edit request on 14 July 2015
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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)[reply]
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)[reply]
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)[reply]
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. Serendipodous10:18, 14 July 2015 (UTC)[reply]
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)[reply]
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. Serendipodous10:30, 14 July 2015 (UTC)[reply]
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)[reply]
@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)[reply]
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. Serendipodous11:06, 14 July 2015 (UTC)[reply]
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)[reply]
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. Serendipodous11:14, 14 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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? Serendipodous11:33, 14 July 2015 (UTC)[reply]
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. Serendipodous11:49, 14 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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. Serendipodous13:08, 14 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
Semi-protected edit request on 14 July 2015
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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)[reply]
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)[reply]
(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)[reply]
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)[reply]
"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.
"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
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.
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)[reply]
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-talk10:07, 16 July 2015 (UTC)[reply]
@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)[reply]
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-talk19:08, 16 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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. Serendipodous12:42, 16 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
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 Horizonsspacecraft 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)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
BRIEF Followup => rv edit - removing section withoutWP: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)[reply]
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. Serendipodous19:17, 17 July 2015 (UTC)[reply]
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)[reply]
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. Serendipodous20:31, 17 July 2015 (UTC)[reply]
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)[reply]
"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. Serendipodous20:59, 17 July 2015 (UTC)[reply]
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:
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)[reply]
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. Serendipodous20:54, 18 July 2015 (UTC)[reply]
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)[reply]
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)[reply]
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)[reply]
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)[reply]
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. Serendipodous21:16, 18 July 2015 (UTC)[reply]
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 PlutoorNew 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)[reply]
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)[reply]
Done -- Kheider (talk) 15:45, 14 July 2015 (UTC)[reply]
