Talk:Charon (moon)

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Wrong timestamp on picture[edit]

The picture was taken on July 13th per http://apod.nasa.gov — Preceding unsigned comment added by Vencaslac (talkcontribs) 08:17, 17 July 2015 (UTC)

flyby and current events[edit]

Can someone add the current events to this just like Pluto and NH JSon94 (talk) 05:59, 15 July 2015 (UTC)

Travesty of mispronunciation[edit]

Charon is the ferryman of the dead who brings the souls of the dead to the underworld where Pluto reigns. It is pronounced KAYRON or KYRON. but, the wife of the guy who first observed the moon is called "Char" or "Sharon"...... SO, now we are told to mis-pronounce the name of the moon as "sharon" after her....!!! This is preposterous. What the hell Sharon the housewife got to do with the moon and mythology of Pluto beside providing bed-time service to the fellow who first observed the moon??? These things are to last for thousands of years. However, astronomy has become the "old boys" private club. They do what they want and get away with it. I am waiting for the "spaceship tampon" to be named after someone else's accessories.... NONE OF YOU SHOULD mispronounce Pluto's moon--KAYRON--as "sharon"!!! Total travesty. — Preceding unsigned comment added by 66.108.184.225 (talk) 19:11, 26 May 2014 (UTC)

... Uh huh. You do realize both the pronunciation of the mythological figure (hard c) and the portmanteau of Charon and Sharon are officially accepted, right? Same for the pronunciation of the mythological Dysnomia and the Dysnomia-Diane pronunciation. 134340Goat (talk) 21:56, 26 May 2014 (UTC)
I visited this page just to know this - canonical pronunciation of the term. Well what is the consensus? It would be nice to have it expressed in the main text. Well, personally, I like "Sharon" in the sense written above though I am not opposed to the other. Thanks --Wordmasterexpress (talk) 04:09, 8 July 2015 (UTC)
Have you checked the "Name and pronunciation" section? Major dictionaries give the one with initial [k], though among astronomers the one with initial [ʃ] ("Sharon") is common. Double sharp (talk) 14:52, 8 July 2015 (UTC)

Her name was Charlene, not Sharon; she was always known as 'Char', and the 'on' was added because it sounded 'science-y'. — Preceding unsigned comment added by 91.84.79.247 (talk) 04:23, 15 July 2015 (UTC)

number in name[edit]

"(134340) Pluto I": isn't the number prefix generally dropped from DPs, so wouldn't this be just "Pluto I"? — kwami (talk) 09:42, 30 August 2010 (UTC)

Dysnomia, Vanth, and Weywot still shows their numbers, yet Pluto's moons Hydra and Nix do not. (Keep in mind that when Pluto's moons were discovered Pluto did not have a MPC number.) The MPCs list of binary asteroids shows the designation including the number: http://www.cfa.harvard.edu/iau/minorsats.html -- Kheider (talk) 17:32, 30 August 2010 (UTC)
I understand that minor planet moons retain the number of their primary. However, I was under the impression that when a body is declared a DP, the number is dropped for most purposes. E.g., we move the DP articles to titles w/o the numbers, and I believe I've generally seen "Eris I", "Haumea II", etc. But perhaps I'm misinterpreting the situation. — kwami (talk) 00:03, 31 August 2010 (UTC)
Even on the wiki Minor_planet_moon#Trans-Neptunian_objects we have a tendency to drop the MPC number as a style of shorthand. We also have List_of_TNOs#Moons_of_trans-Neptunian_objects. I guess it depends on how formal we want to be? -- Kheider (talk) 00:50, 31 August 2010 (UTC)
We should be formal in giving alt designations in the lede defining what the object is, so we should have the number if it's used for DP moons. — kwami (talk) 01:16, 31 August 2010 (UTC)

Eclipses[edit]

"This occurs when the Pluto-Charon orbital plane is edge-on as seen from Earth". Eclipses occur when Sun is in Pluto-Charon orbital plane, it doesn't depend on Earth's position. --91.201.0.186 (talk) 13:05, 27 October 2010 (UTC)

I added transits since they do depend on the Earth's position. As seen from distant Pluto, Earth and the Sun are almost in the same position and plane. -- Kheider (talk) 16:07, 27 October 2010 (UTC)

Alternative picture[edit]

Charon.png

This is designated as a "lok" (limit of knowledge) surface in Celestia, so this should be OK when the File:Charon plutoface.png can't be used. Lanthanum-138 (talk) 11:28, 7 July 2011 (UTC)

Well, which is more accurate? If the answer is "we really don't know what the surface looks like," it seems to me that the photo above would be a better way of saying that than the image in the article currently, which looks like a disco ball. Neutron (talk) 22:13, 20 July 2011 (UTC)
Both images are derived from the mapping work of Marc W. Buie. However we don't have problems with the picture I uploaded like we do for Charon plutoface.png. We are not sure what the surface looks like: I'll upload a map. Lanthanum-138 (talk) 11:32, 26 July 2011 (UTC)

Mass Effect Reference[edit]

I- believe a Popular Culture section should be added to mention the Mass Effect game reference. Check this link http://masseffect.wikia.com/wiki/Charon_Relay — Preceding unsigned comment added by 201.124.48.232 (talk) 03:07, 9 November 2011 (UTC)

If anyone cares to edit the pop culture reference, one does not go and discover "solar systems" since that term refers specifically to the planetary system which contains the star Sol. Which just happens to be ours. Planetary system may be more accurate? 138.163.128.42 (talk) 16:49, 12 July 2012 (UTC)

Mass Effect in turn got the idea from a 1962 Galaxy article entitled "Pluto is Black!" written under the pseudonym George Peterson Field by Dr. Robert L. Forward. The article was republished in 1978 in the anthology Black Holes, edited by Jerry Pournelle ISBN 0-449-23962-4
Dr. Forward was speculating upon the (then wrong) mass estimates for Pluto combined with the estimated diameter (also wrong) which in-turn lead to an unreasonable density. He then went on to describe various ways to use gravity catapults. I apologize for the sloppy editing69.210.251.230 (talk) 02:43, 25 January 2014 (UTC)

Pluto/Charon as Kuiper Belt Binary[edit]

Ladies, Gents, Wikipedians --

Charon is not a moon of Pluto -- they are binary objects orbiting a common barycenter that's outside of both objects. I think we need to focus the discussion to describe this, as well as make reference to the significant number of binary objects in the Kuiper Belt. Dioxinfreak (talk) 16:18, 9 July 2012 (UTC)

That depends on one's definition of when something is a double "..." vs. a "..."–satellite system. There is no agreed-upon one. --JorisvS (talk) 16:34, 9 July 2012 (UTC)
According to Satellites and Companions of Minor Planets, Charon is a Satellite of Pluto. Jupiter is still a planet even though the Sun-Jupiter barycenter is above the Suns surface.-- Kheider (talk) 19:00, 9 July 2012 (UTC)
The is no clear-cut definition of what distinguishes an object-moon system from a binary object system. In the absence of such a definition, we should follow the common understanding of any particular system. As fas as I can tell, NASA and other reputable organizations continue to refer to Charon as a moon of Pluto. Wikipedia is meant to document things as they are, not state the beliefs of its editors about how things should be. So to refer to the Pluto-Charon system as a binary system here due to our personal beliefs about what makes a moon, however reasonable those beliefs may be, would be a misuse of wikipedia. If a scientific consensus emerges or an authoritative organization makes a statement that distinguishes moon from binary in such a way that Charon falls into the latter category, then we can make the changes here. But that discussion is the job of the astronomers out there, not us lowly documenters here. A2soup (talk) 18:18, 3 July 2015 (UTC)
In fact, there are binary systems where the secondary is only slightly smaller than the primary. I've even seen those secondaries referred to as moons (i.e. that 'secondary' and 'moon' are simply synonyms). --JorisvS (talk) 21:29, 3 July 2015 (UTC)

Date on Charon image wrong?[edit]

Wasn't the picture of Charon taken during the flyby and released today? The wiki says July 15th. — Preceding unsigned comment added by InterfaceManager (talkcontribs) 19:28, 15 July 2015 (UTC)

The date is apparently correct, see this source. A2soup (talk) 14:12, 17 July 2015 (UTC)
July 14th was the date of closest approach to Pluto, which doesn't mean all photos of the Plutonian system are taken on that day. Vencaslac (talk) 05:45, 22 July 2015 (UTC)

Two recent confusions over the hatnotes[edit]

The {{current event}} template does not require a hundred editors swarming down on this article. It allows for that as an unusual application. That is not a mandated requirement, and deleting the template because we're not in that unusual situation is pure incompetence. In the present situation, we have a bona fide current event, and yes, information is subject to rapid change, and we are providing a friendly heads-up to our readers about the status of the contents they find here.

WP:DABLINK spells out when to add a hatnote, and when not to. The basic rule is to help the likely reader who has come to the wrong article without realizing it. In the case of an explictly dabbed title, someone who gets to this article is in no way confused about expecting some other "Charon", so telling him the good news is only adding to his confusion, not helping. Choor monster (talk) 11:35, 20 July 2015 (UTC)

The template says Information in this article may change rapidly, which won't happen. This is not a developing news story, we get new information about Charon in batches that are typically separated by a day or more. The part that says Initial news reports may be unreliable is also irrelevant here. --Njardarlogar (talk) 14:15, 20 July 2015 (UTC)
Yes, it will happen. NASA/APL releases new information, and information in this article will change rapidly. That's my take. If consensus is that "rapidly" here means information will likely change as you're reading, as opposed to change in rapid-fire bursts every so often, then I agree to its removal. I just don't see that though. I view the purpose of the tag is to contrast with articles about material for which the information and sources have been out there for quite some time, just nobody has bothered to write a full article yet.
However, I do not agree to its removal by people who think the special case of a crowded rush of editors, listed in the documentation, is required for the template. That's just a misreading of basic logic and English, and until now, that has been the only reason stated for its removal. Choor monster (talk) 14:28, 20 July 2015 (UTC)
I agree with Njardarlogar that information is not going to change on Charon that fast. If there is an important discovery, then the tag can be re-applied. I believe press announcements will generally be made on Fridays. -- Kheider (talk) 15:17, 20 July 2015 (UTC)
What is the point of including the tag? What purpose does it serve? I can see none. There is no current event (it has passed). The information will only gradually trickle into this article. --JorisvS (talk) 16:16, 20 July 2015 (UTC)
  • Now that people are objecting to the tag for valid reasons, I yield to the consensus, and have self-reverted. Choor monster (talk) 16:23, 20 July 2015 (UTC)

External links[edit]

Should they be heavily trimmed? Choor monster (talk) 16:05, 22 July 2015 (UTC)

Yeah. It's mostly out of date now. — kwami (talk) 17:03, 22 July 2015 (UTC)

STOP using fake color images on wikpedia for the main image[edit]

This is ridiculous, first Pluto, now Charon, DON'T USE ANOTHER THING THAN NATURAL COLORS, this is an encyclopaedia not a fake color site. — Preceding unsigned comment added by 62.83.153.1 (talk) 14:00, 2 October 2015 (UTC)

It is of much higher resolution, showing many of its surface features far better, and hence should be included in the article, regardless of whether it is used in the infobox. --JorisvS (talk) 15:42, 2 October 2015 (UTC)
Despite the anonymous IP editor's frantic tone and COMPELLING USE OF ALL CAPS, I am inclined to second JorisvS' response. Eric talk 17:42, 2 October 2015 (UTC)
There is a difference between "false" color and "fake" color. Fake color is more an opinion than anything else. What we have here is "exaggerated" or "enhanced color" which is similar to pictures of raised relief maps where the vertical dimension is exaggerated. The pictures of Charon and Pluto have the right colors as would be seen by the naked eye, but the lightness is exaggerated. There is no green blue and purple in them as a false color picture would have. Because they have greater resolution than the previous ones, I honestly believe that they should remain.Rudy235 (talk) 21:02, 2 October 2015 (UTC)

I will improve this article[edit]

I have checked the page view statistics and it is a fairly popular article. However, it is still too short and it's just bad overall. There are tons of info from new horizons that should be added. I will expand this later at night. If anyone can help, that'd be great Huritisho 18:52, 7 October 2015 (UTC)

I just grabbed a nice cup of coffee - let's do it Huritisho 23:54, 7 October 2015 (UTC)

I think I should stop for a while. I have too many edits in a row. I wish I could make more changes in a single edit but that is not as simple as you might think Huritisho 05:27, 8 October 2015 (UTC)

There's no such thing as "too many edits in a row". However, if you like, you can copy the article to your sandbox and edit it there. You can tag this page with {{under construction}} until you're done, so other people don't make edits that will get reverted when you copy back. — kwami (talk) 16:39, 8 October 2015 (UTC)
I take it back. If you can't do arithmetic on a calculator, then you shouldn't be editing the figures. — kwami (talk) 02:30, 16 October 2015 (UTC)
I have included the numbers for Surface Gravity and Escape velocity. This are derived from these formulas Surface gravity derived from the mass M, the gravitational constant G and the radius r: GM/r^2. and Escape velocity derived from the mass M, the gravitational constant G and the radius r: \sqrt{2GM/r}. Unfortunately I cant link this to the references or Notes as much as I tried. Perhaps someone can help here.Rudy235 (talk) 03:51, 16 October 2015 (UTC)
Thanks. We still need updated albedo and axial tilt, which Huritisho deleted because they think we're supposed to indicate false certainty. — kwami (talk) 05:12, 16 October 2015 (UTC)
@kwami I think the Albedo should be given with it's source That info there has no source and it is also not with a 0 degree phase angle. The axial tilt also needs a reliable source.Rudy235 (talk) 20:10, 16 October 2015 (UTC)

Kwamikagami, stop adding the {{cn}} tag[edit]

You're not supposed to add a citation needed tag where there is no claim being made. Example:

The above is fine

This one is not

Now please stop adding the tag. Huritisho 02:51, 16 October 2015 (UTC)

I think I found a way to include the ratio of Charon Volume to Earth Volume without the [citation needed] By the way Relative Volume = (R1/R2)^3Rudy235 (talk) 03:04, 16 October 2015 (UTC)
Thanks but that's not what I was referring to. The problem is adding the {{cn}} where there is no numerical value. Huritisho 03:07, 16 October 2015 (UTC)
Understood Rudy235 (talk) 04:01, 16 October 2015 (UTC)
Huritisho, if you're not competent to edit the article, you shouldn't be editing it. See Wikipedia:Competence is required. — kwami (talk) 04:48, 16 October 2015 (UTC)
Kwami, speaking only to the "CN" issue here, do please stop. If data for a field is not known, leave the field blank. Do not use question marks or citation needed tags. Huntster (t @ c) 05:24, 16 October 2015 (UTC)
@Huntster: He added a question mark once again. He also added unsourced data. Please revert that for me Huritisho 05:45, 16 October 2015 (UTC)
Funny, after complaining about it, Huritisho is now adding 'cn' tags to info-box fields. He's also started blanking info from the boxes. — kwami (talk) 06:19, 16 October 2015 (UTC)
I didn't notice the cn tag would return after reverting. It was an accident Huritisho 06:22, 16 October 2015 (UTC)

Please stop with the changes[edit]

You're ruining the infobox. Do not add question marks in the fields. If the value is not known, just leave it blank so it will disappear from view. That's incompatible with how things are done in Wikipedia. Huritisho 05:06, 16 October 2015 (UTC)

It's quite hypocritical of you to revert people for following your instructions. You are incompetent, incapable of even simple arithmetic or understanding the sources of the article. You have no idea how things work here, and are gumming up the article for the rest of us. Go away and leave the "improvements" to someone who will actually improve the article. — kwami (talk) 05:10, 16 October 2015 (UTC)
By the Way I wish someone would improve Ref 4 It should read something like this: The Pluto system: Initial results from its exploration by New Horizons S.A. Stern et. al. October 16, 2015 Table 1
Right now it does link to the said Table 1 but I am not able to include the Reference Name.Rudy235 (talk) 15:23, 16 October 2015 (UTC)
Done. Just fixed that for you Huritisho 16:15, 16 October 2015 (UTC)
THANK YOU! Rudy235 (talk) 20:12, 16 October 2015 (UTC)
NO PROBLEM! Huritisho 21:40, 16 October 2015 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── Note: both accounts are under investigation as socks of banned user Tetra quark. — kwami (talk) 23:07, 17 October 2015 (UTC)

@Kwamikagami: Why on earth would I use two different accounts simultaneously? Huritisho 17:59, 18 October 2015 (UTC)
To make it look like others approve of your edits. It's been done before. But that's for the sock investigation to decide. You could be innocent, or you could be changing your ways. That's happened before too (vandals becoming productive editors). I don't really care, as long as your edits improve WP, as your most recent ones have. — kwami (talk) 18:14, 18 October 2015 (UTC)
Hm I understand. But in this case, even if I were Rudy it would be pointless ask help to myself. I guess I would just make the edit, unless of course if I were willing to try really hard to make it seem like we're different persons. By the way, thanks for saying my edits are good. I thought you had a problem with me Huritisho 18:21, 18 October 2015 (UTC)
confirmed: This account has been confirmed by a CheckUser as a sock puppet of Tetra quark (talk · contribs · logs), and it has been blocked indefinitely.

REFERENCE 27 needs to be fixed[edit]

Reference 27 has some issues. Can someone edit it please? I am not able to. This is what it looks like: Cite error: The named reference :1 was invoked but never defined (see the help page).

This is it looked like before: Cook; et al. (2007). "Near-Infrared Spectroscopy of Charon: Possible Evidence for Cryovolcanism on Kuiper Belt Objects". The Astrophysical Journal 663 (2): 1406–1419. Bibcode:2007ApJ...663.1406C. doi:10.1086/518222.Rudy235 (talk) 06:44, 18 October 2015 (UTC)

The bot has fixed the ref for you. The ref doesn't have that content you mentioned, however.Huritisho 10:15, 18 October 2015 (UTC)
In order to add that ref you mentioned, open visualeditor, click "Cite", and paste the doi (which is 10.1086/518222). It will automatically generate a ref for you. I ask you to do that, since I don't know exactly where the ref is supposed to be Huritisho 10:23, 18 October 2015 (UTC)
That reference 27 was there before as Cook et al. (2007) but I see that numbers move up and down. So Cook et al. (2007) is now reference 24 as a result of me consolidating some references Science 2015, Science 2015(a) and Science 2015(b) into one. I think things should be ok as they are. We shall see.Rudy235 (talk) 16:15, 18 October 2015 (UTC)

Flattening or Oblateness[edit]

The recent study DOI: 10.1126/science.aad1815 establishes and upper limit for the flattening of Charon. It estimates that the difference in Radii is less than 1%. This seems to me like a very conservative estimate if you consider that the Earth which has a 6 times faster rotation has a flatening of around 1/3 of 1%. However, we cannot insert our own opinion and the cited source will have to prevail until proven otherwise.--Rudy235 (talk) 17:46, 18 October 2015 (UTC)

It's a measurement. They can only measure what they can measure, and we can only report measurements that have been made. Where oblateness is perhaps most pertinent is if it demonstrates that a body is in hydrostatic equilibrium. That has not been demonstrated for Pluto, Charon or Ceres, and therefore it has not been demonstrated that they are dwarf planets. However, since the category of DP was created for Pluto, if it turns out that Pluto is not in HE, it's possible that the IAU will change the definition of DP accordingly. It's unlikely that Pluto is not in HE, given its size, but it is quite possible that Charon and Ceres are not, in which case the Plutonian system cannot be characterized as a double planet even by those like Stern who accept DPs as planets. But such speculation depends so heavily on how others interpret the definitions of the terms that we really cannot go there without sources. — kwami (talk) 18:23, 18 October 2015 (UTC)

Just how bright is Charon as seen from Pluto?[edit]

We've all seen the magnificent images of Pluto and Charon, and it's easy for a layman to think that this is how bright they actually are at that range. (In reality, of course, they're long exposures and have been enhanced.) Assuming it were possible for somebody to stand on Pluto's surface and look at Charon, what would they see? Something like the Moon during a total eclipse, with features visible, a black disk that's only deduced by the fact that it occludes stars as it goes past, or something in-between? And, of course, the reverse: what would Pluto look like from Charon? I ask not just because I'd like to know, but because I think that it would improve the article, and help people understand just how little light there is out there, and how much our instruments can do with it. JDZeff (talk) 21:32, 14 December 2015 (UTC)

Orbit[edit]

An oblique view of the Pluto–Charon system showing that Pluto orbits a point outside itself. Also visible is the mutual tidal locking between the two bodies.

This image in the article is misleading. As viewed from above Solar system Pluto's rotation is clockwise (see for example, in this book. And Charon is in retrograde motion around Pluto (see in this book) and hence Charon's motion is also clockwise when viewed from above. This should be pointed out in the article and image corrected. Illustr (talk) 20:18, 27 March 2016 (UTC)

I see from your sources that Pluto's rotation is clockwise, and that Charon's orbit is also clockwise, which only makes sense if it is tidally locked with Pluto. The picture is not going to depict reality perfectly no matter what, because the reality (from your source) appears to be that Charon's orbit is inclined 118˚ to Pluto's orbit, making it technically clockwise but more sideways than anything. I agree, however, that the image would be better if reversed. I lack to skills to do this, and unfortunately the image's creator, StephHoover, appears to be inactive. Can anyone else reverse the image?
If no one can, I would still keep the image. It's quite informative as to how the Pluto-Charon system looks and is accurate from some real angle, even if it isn't the one dictated by convention (which is also mostly wrong in this case, since Charon is really sideways). A2soup (talk) 21:06, 27 March 2016 (UTC)

Proposed merge with Geology of Charon[edit]

Can easily be covered by this article. MartinZ02 (talk) 21:16, 8 July 2016 (UTC)

  • Oppose Geology of Charon was split off as a result of an earlier discussion. As more information comes on this topic Geology of Charon will get bigger and bigger and Charon (moon) would be too large to include all of that topic. Graeme Bartlett (talk) 00:47, 9 July 2016 (UTC)
Articles should be split when they become to large, not because they may become to large several years into the future. MartinZ02 (talk) 00:37, 13 July 2016 (UTC)
But it is not a prerequisite for splitting (or rather, in this case, covered this topic on a new page), i.e. it is not necessary for a page to first be very large before a subtopic can have its own article. --JorisvS (talk) 19:32, 13 July 2016 (UTC)
There's no meaning in having a child article if the parent article isn't to large. —MartinZ02 (talk) 00:25, 14 July 2016 (UTC)
It depends on where you draw the line. For me, it does make sense at the current sizes. --JorisvS (talk) 17:53, 14 July 2016 (UTC)
According to WP:SIZERULE, articles with less then 40 kB readable prose size should not be split because of its size. —MartinZ02 (talk) 19:04, 14 July 2016 (UTC)