Talk:Moons of Jupiter

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Featured list Moons of Jupiter is a featured list, which means it has been identified as one of the best lists produced by the Wikipedia community. If you can update or improve it, please do so.
Featured topic star Moons of Jupiter is part of the Jupiter series, a featured topic. This is identified as among the best series of articles produced by the Wikipedia community. If you can update or improve it, please do so.
WikiProject Solar System (Rated FL-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Solar System, a collaborative effort to improve the coverage of the Solar System on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Featured list FL  This article has been rated as FL-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 
For more information, see the Solar System importance assessment guideline.
WikiProject Astronomy (Rated FL-class, Mid-importance)
WikiProject icon Moons of Jupiter is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Wikipedia.
Featured list FL  This article has been rated as FL-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 

Archive 1

to do[edit]

  • Add apparent magnitudes
  • format refs: done except w/ 28-31
  • last name, first name
  • rewrite the masses
  • ref eccentricities
  • play around with the unlinked notes in the table
  • no break spaces for units

Yes check.svg Done Nergaal (talk) 06:45, 2 September 2008 (UTC)

Mass[edit]

I think some mention should be made in the lead of the extreme mass imbalance in the Jovian system. I've done a calculation (will need to be checked) that the total mass of all the 59 non-Galilean satellites combined comes to 1.07x10^19, or 0.02 percent the mass of Europa, the smallest Galilean. Serendipodous 09:50, 5 September 2008 (UTC)

The small moons don't even show up.
Yes, good point. Jupiter really does have four moons and a bunch of rocks. Something like a pie chart would be good for all the gas/ice giants. kwami (talk) 09:59, 5 September 2008 (UTC)
I'm not sure a pie chart would work for Jupiter. On a scale of 10,000 to 1, you'd basically have to point to the line between Ganymede and Europa and say, "All other moons." :-) Serendipodous 10:15, 5 September 2008 (UTC)
Yeah, but we can have a chart for all the planets, and when it comes to Jupiter, just say that the others are so tiny they don't even show up. It might still get the point across in a way that raw numbers wouldn't. kwami (talk) 10:37, 5 September 2008 (UTC)
I get the same mass for all the small moons, but that comes out to only 0.003% the total. The others are 22%, 12%, 38%, 28%. kwami (talk) 10:18, 5 September 2008 (UTC)
I was measuring against Europa only. Serendipodous 10:20, 5 September 2008 (UTC)
My brilliance at work! Anyway, I made a pie chart. Will upload in a minute. kwami (talk) 10:33, 5 September 2008 (UTC)
Nice coincidence how the masses of Io & Callisto are equal to Europa + Ganymede.
The seven 'dwarf planet' moons. Mimas doesn't show, let alone the small moons.
Now Saturn looks very different. I was surprised to see that even Mimas doesn't show up, and that I had to enlarge the chart to see Enceladus. kwami (talk) 10:53, 5 September 2008 (UTC)
Great charts! We may need to create a separate section on mass to put them in though. Serendipodous 11:03, 5 September 2008 (UTC)

2 comments on the pie chart:

Personally I think a pie chart is a poor way to represent that masses of Jupiter's moons... Pie charts are supposed to represent fractional proportions and its not clear what this is all a fraction of, and I'm not sure if a fraction is relevant unless it's with respect to something useful. What does the % actually refer to (it doesnt say on the article)?
wrt "Those smaller than Europa are not visible at this scale, and combined would only be visible at 100× magnification"... Are you sure? If MS excel made this picture 100x larger would it print out a segment for the low mass moons? I wouldn't think so.
It is a fraction of the mass in orbit around Jupiter. And it does say that in the article. Serendipodous 07:02, 8 September 2013 (UTC)

Rings[edit]

There's no mention of how the moons maintain the rings. Serendipodous 11:59, 5 September 2008 (UTC)

added a line. Serendipodous 12:10, 5 September 2008 (UTC)


irregulars image[edit]

I've found a nice image with the orbits of teh irregulars above 10km in radius here - figure3. Is it ok to upload it? It would very nicely present the groupings of the outer satellites. Nergaal (talk) 20:36, 5 September 2008 (UTC)

Yes, that's a nice image. Is it not copyrighted? It does suggest that the outer moons may be the shattered remains of a relatively small number of bodies, doesn't it?

Leda[edit]

Leda would appear to have ten times the density of other moons its size. Can s.o. confirm the mass and diameter aren't off? kwami (talk) 08:55, 6 September 2008 (UTC)

according to NASA figures, it has a mass of 6 x 1015 kg and a radius of 5 km, which would, by my calculations, give it a density of 11.5. That seems ridiculous. To be that dense it would have to be made mostly of gold or lead.Serendipodous 09:10, 6 September 2008 (UTC)
I've subbed it with info from this Fukuoka University page. Seems to produce a more logical density. Serendipodous 08:27, 8 September 2008 (UTC)
Thanks. I wrote to NASA asking them to fix their page. We should probably place a note on the Leda entry, since the Fukuoka data is rather old. kwami (talk) 10:18, 8 September 2008 (UTC)
Added a commented out link. Serendipodous 12:16, 8 September 2008 (UTC)

Formation[edit]

I can't believe we forgot to put a formation section in here. I'll get on it. Serendipodous 09:36, 10 September 2008 (UTC)

Actually, come to think of it, the formation section would probably be best in Galilean moons. Serendipodous 11:06, 10 September 2008 (UTC)

I was planning on having a formation section but as I went through I realized that most of that info is allready covered in the Groups section. Basically Galilean moons formed in situ, while the others were more or less captured and broken asteroids (exceptions noted too). Besides that, the only thing that could be added is detail about the GM part, which as you said, would go in the GMs article better. Nergaal (talk) 16:23, 10 September 2008 (UTC)

There is actually something that this article does not cover at all, and that is explaining how & why the Galileans got to the present resonance. Nergaal (talk) 09:52, 12 September 2008 (UTC)

Does that belong here, or in the Galilean moons article? Serendipodous 10:21, 12 September 2008 (UTC)
It definitely should be discussed in Galilean moons (which it isn't) and maybe Orbital resonance as well. I would say that a summary sentence or two would be appropriate in this article.
A review of the topic can be found in Peale and Lee (2002)[1], which cites all of the relevant previous papers as well as providing new arguments in favor of a primordial origin for the resonance. I would say that the idea of evolving into the resonance through tidal expansion is still a very viable model, and should be equally discussed. --BlueMoonlet (t/c) 13:08, 12 September 2008 (UTC)
I can't access it from my terminal. Do you think you could add it? Serendipodous 13:43, 12 September 2008 (UTC)

new horizons[edit]

did the probe show anything interesting about the moons besides the volcanoes on Io? Nergaal (talk) 01:07, 16 September 2008 (UTC)

They found lots of interesting things, but nothing revolutionary, as far as I can tell. Serendipodous 04:55, 16 September 2008 (UTC)

[2]

It's good to have a snapshot of the system every once in a while, just so we know what's normal. Too bad we didn't have Galileo there when Shoemaker-Levi hit. kwami (talk) 05:48, 16 September 2008 (UTC)

I just wanted to make sure that nothing was missing from this list (I am slightly surprised that with its good camera, horizons did not look at any of the smaller moons). Nergaal (talk) 06:03, 16 September 2008 (UTC)

Current number of natural satellites?[edit]

Is the current confirmed number 62 or 63? The main article starts off with saying there are 62, but the table shows 63, is there one that is listed but unconfirmed? Sethhater123 (talk) 02:08, 19 September 2008 (UTC)Sethhater

Also, the NASA website seems to state that there is 62 and not 63 satellites : http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=Moons G0rth0r (talk) 02:21, 8 February 2009 (UTC)
It seems that S/2000 J 11 has gone missing from reading that moon's article.--Roentgenium111 (talk) 21:19, 18 October 2010 (UTC)

Two more so now 65!

http://www.minorplanetcenter.net/mpec/K11/K11L06.html If anyone has access to the IAU circulars, if/when one appears for these a check would be useful. 202.7.182.10 (talk) 09:14, 2 June 2011 (UTC)

I'd say "now 64" (if this is confirmed), given my above comment on S/2000 J 11.--Roentgenium111 (talk) 16:21, 2 June 2011 (UTC)

April 2012: The opening paragraph states that there are 66 moons, which is in agreement with the Table information, but the final paragraph of the Discovery section states that there are (only) 63 moons. I realize that this information can change but I think that it's a minimal requirement for an encyclopedic article about the moons of Jupiter to get the number right, or at the very least be self-consistent. Someone seems to have dropped the ball here. nagualdesign (talk) 09:06, 20 April 2012 (UTC)

An MPEC has been issued today giving the recovery of S/2000 J11 last year by Sheppard et al. see http://www.minorplanetcenter.net/mpec/K12/K12R22.html Andrew W 202.7.182.10 (talk) 08:07, 11 September 2012 (UTC)

Seeing that S/2000 J11 was observed multiple nights over multiple years, sounds like a recovery to me. -- Kheider (talk) 17:36, 11 September 2012 (UTC)

???? the article starts off with a claim of 67 confirmed moons, and then later on that is reduced to 63 moons in the 'Discovery' section. Should not the article at least agree with itself? Note this discrepancy was reported above in April 2012 when the counts were 66 and 63, Suggest the count be reduced to 63 in the opening paragraph Edantu (talk) 12:05, 2 June 2013 (UTC)

This article received the FL star on 14 September 2008 when it was stated that there were 62 confirmed moons (S/2000 J 11 was lost at the time). It was the discovery section that needed to be updated. Four moons have been discovered post-2003, so we have 63+4=67 moons. 16 have been discovered but not yet named since 2003. -- Kheider (talk) 14:37, 2 June 2013 (UTC)

Number of moons in the past[edit]

It's worth mentioning that the current moons are believed to be the ones that survived their formation process. New Scientist (7 March 2009) has an article on the subject if you'd like a reference. I would add it myself but am unable to because of semi-protection. The article ("Cannibalistic Jupiter ate its early moons" by Marcus Chown, page 11) gives an estimate of up to 20+ for the number of Galilean moons the planet could have originally had. Recognizance (talk) 22:08, 17 March 2009 (UTC)

The article is available online at http://www.newscientist.com/article/mg20126984.300-cannibalistic-jupiter-ate-its-early-moons.html. Recognizance (talk) 16:35, 18 March 2009 (UTC)

new section[edit]

I added a new section on origin & evolution based on User:Recognizance's link. It could use some editing by someone who really knows what they're talking about, and we might want to migrate to here material on origins now scattered through the article.

I only added a link to the popular summary. The original article on the evolution of Europa is here.[3] kwami (talk) 00:22, 19 March 2009 (UTC)

Okay, this is going to need some work. I removed some nonsense from recent edits (such as "trapped in the gravitational field"), but what's left is contradictory. For example, we claim that the early galileans spiraled into Jupiter, but then say that new moons formed from their debris. We also claim that a large mass "passed through" the disk, but never say where it came from--the solar disk, perhaps? kwami (talk) 10:31, 19 March 2009 (UTC)
By "newly accreted debris" I meant new material that accreted by Jupiter from Solar nebular (not debris of moons). Ruslik (talk) 11:09, 19 March 2009 (UTC)
You mean material pulled in from the Solar nebula to replace that depleted by the accretion of the moons? kwami (talk) 11:20, 19 March 2009 (UTC)
Yes. Ruslik (talk) 11:25, 19 March 2009 (UTC)

Fantastic. The idea of such a section occurred to me while I was reading the article, but it had been mentioned on the talk page (and was already at FA status) so I didn't want to mess with it. But this definitely improves the article. I do think it belongs earlier in the article though. Recognizance (talk) 16:48, 20 March 2009 (UTC)

Another thought with respect to organization: The naming section as a subsection of the discovery section. Moons are named as they're discovered, so the two are inherently related. I can go either way on it though so I refrained from making the change on my own. Recognizance (talk) 16:59, 20 March 2009 (UTC)

not dwarfs[edit]

Comet Ganymede?

The article contains the following sentence: "The Galilean satellites are spheroidal in shape, and so would be considered dwarf planets if they were in direct orbit about the Sun." But Ganymede is larger than Mercury, and Mercury is a fullfledged planet, not a dwarf planet. I believe, though I don't have the figures, that the other three are also near Mercury's size. If they were in direct orbit around the sun, they would be classified as planets as well. CharlesTheBold (talk) 04:26, 16 June 2009 (UTC)

It is more complicated than that:
  • (1) Mercury (3.3E+23 kg) is more massive than Ganymede (1.4E+23 kg). It is mass (not volume) that helps an object dominate its region.
  • (2) It would also depend on how far the object orbits from the Sun. The further from the Sun, the more massive it needs to be to dominate the region.
  • (3) If Ganymede got too close to the Sun it might look a lot like a comet. -- Kheider (talk) 05:57, 16 June 2009 (UTC)
Either way, claiming they would be dwarf planets seems OR to me, since they might indeed be planets depending on circumstances. So the quoted sentence should be reworded in my opinion.--Roentgenium111 (talk) 16:24, 2 June 2011 (UTC)

??? = Jupiter L Herse[edit]

USGS Astrogeology has a news item up about a newly named moon of Jupiter, discovered in 2003 by Gladman et al. Unfortunately, there are multiple unnamed moons fitting that description and I can't find any info on which one it is. Link here. Can anyone else find out more so we can start the name-changing spree on related articles and lists? --Patteroast (talk) 04:52, 11 November 2009 (UTC)

It is S/2003 J 17. Ruslik_Zero 13:20, 11 November 2009 (UTC)

Classify Trojans as Moons?[edit]

The Jupiter Trojans, such as 624 Hektor (~1.4×1019 kg) are technically in orbit around Jupiter at a distance of ~5.2 AU. Should these be included as moons? If they were then 624 Hektor would be the 5th largest moon of Jupiter. If they are not included as moons they should still be mentioned as objects of relevance to the article. --Tediouspedant (talk) 13:02, 18 February 2010 (UTC)

They're not in orbit about Jupiter. They're in orbit about the Sun in resonance with Jupiter. We wouldn't say that Pluto is a moon of Neptune. kwami (talk) 13:16, 18 February 2010 (UTC)
Using JPL's Orbital simulation (Java) and zooming out with a timestep of say 10 days, you can clearly see that Hektor orbits the Sun and not Jupiter. -- Kheider (talk) 18:45, 18 February 2010 (UTC)
Pluto does not remain a constant distance from Neptune, but 624 Hektor remains a constant distance (~5.2 AU) from Jupiter [See correction below --Tediouspedant (talk) 15:43, 19 February 2010 (UTC)]. Viewed from Jupiter 624 Hektor would be seen to follow a circular orbit around the planet just like its nearer moons. As 624 Hektor forms an equilateral triangle with Jupiter and the Sun it consequently orbits both bodies simultaneously. This can be seen from JPL's orbital simulation. There may be a convention for not including Trojans as moons but your comment does not provide a reason for this. --Tediouspedant (talk) 23:36, 18 February 2010 (UTC)
Being seen to follow a circular orbit around Jupiter is not the same as orbiting Jupiter. Even over a short simulation (2010-2050) Hektor can easily vary from 7.1AU from Jupiter (2017-Aug) to 4.3AU from Jupiter (2049-Jul). -- Kheider (talk) 00:50, 19 February 2010 (UTC)
Assuming that an orbit is a cyclical motion resulting from gravitational attraction then 624 Hektor IS orbiting Jupiter (as well as the Sun) and not just appearing to do so. Thanks for the correction on distances. If the cyclical variations in distance between Jupiter and 624 Hektor are mapped out then they will almost certainly reveal an elliptical orbit which is entirely concordant with it being classified as a moon. All the moons of Jupiter have somewhat elliptical orbits. The only reason that I can think of for not counting a Trojan as a Moon (or Pluto as a planet) is linguistic convention. Can anyone provide a reference to such a convention? --Tediouspedant (talk) 15:41, 19 February 2010 (UTC)
The Sun is about 1047x times more massive than Jupiter. Jupiter Trojan Hektor is not a moon because when it librates 7.1AU from Jupiter, it is at most 5.4AU from the Sun. The orbit around the Sun is the DOMINATE and obvious one. "Linguistic convention" can also be thought of as categorization based on common characteristics. Hektor is really no more a moon of Jupiter than Pluto is a moon of Neptune, or 3753 Cruithne is a moon of Earth. -- Kheider (talk) 18:13, 19 February 2010 (UTC)

Naming[edit]

This article provides some interesting facts about the naming of the moons of Jupiter, but now about its system of rendering Greek: is there any reason for Callirrhoe (moon) versus Kallichore (moon), both with Καλλι- in Greek. Does anyone know? Fransvannes (talk) 10:39, 2 February 2011 (UTC)

I dunno. Maybe the discoverers thought the word looked better if spelt the way they chose? Double sharp (talk) 02:59, 24 March 2013 (UTC)

(regarding Refrance number 23)

from: http://galileo.rice.edu/sci/observations/jupiter_satellites.html (6th paragraph down...) The naming of the satellites provides an interesting example of how such matters were handled before the foundation of the International Astronomical Union in the twentieth century. As their discoverer, Galileo claimed the right to name the satellites. He wanted to name them after his patrons and asked whether they would prefer "Cosmic Stars" (after Cosimo II) or "Medicean Stars." They opted for the latter, and through much of the seventeenth century they were known by that name. In his notebooks, Galileo referred to them individually by number, starting with the satellite closest to Jupiter, but he never had occasion to refer to them in this way in print.

the rest of these paragraphs goes on to explain the naming in more detail, should this be added to this section of the article? May 5 2011 —Preceding unsigned comment added by Jessycormier (talkcontribs) 03:35, 15 May 2011 (UTC)

roman numbering[edit]

Roman numbering was at first by distance, and now in order of naming, not order of discovery, correct? — kwami (talk) 16:37, 6 February 2012 (UTC)

I always wonder when I see Roman numerals if it would be wise to change them to Arabic numerals, regardless of historical doting. The year of discovery column has the majorly relevant info. Friendly Person (talk) 17:29, 10 July 2013 (UTC)

No, the Roman numerals are the official usage, and we already have a column with Arabic numerals. Double sharp (talk) 16:31, 19 July 2013 (UTC)

Color the groups of satellites in the table?[edit]

In the Moons of Saturn article, the different satellite groups (Inuit, Gallic, etc.) in the table are colored. If a satellite is in this group, it's colored this color, if it's in that group, its a different color, etc. We should do something like this in the Moons of Jupiter article, e.g. color the Ananke group one color, the Carme group another color, etc. What do you think?

Good idea. nagualdesign (talk) 18:00, 8 July 2013 (UTC)

S/2010 J 1, S/2010 J 2, S/2011 J 1, S/2011 J 2[edit]

Is there any RS for their group assignments? Some time ago, I provisionally (with appropriate question marks, although somewhat OR-ishly) put S/2011 J 1 as its own group, S/2010 J 2 as an Ananke group member, and the other two as Pasiphae group members, hoping to later be corrected. However they seem to have stood. Am I right, or has nobody found a RS assigning these four most recently discovered moons to groups? (Sheppard just puts them with the other unnamed moons, except S/2000 J 11 which he puts in the Himalia group.) Double sharp (talk) 13:32, 3 June 2014 (UTC)

Sorting by orbital period[edit]

The sorting doesn't work for me (IE11): it sorts lexicographically instead of numerically. Double sharp (talk) 14:14, 3 June 2014 (UTC)