Talk:Galilean moons

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Galilean moons

I hope noone minds that I've moved this to "Galilean moons", in the plural, because there is really no such thing as a Galilean moon and the four only have in common their discovery in a group. I know this is not the usual singular convention, but consider usage; Google gives 28x the number of hits for the plural.--Pharos 00:09, 11 Mar 2005 (UTC)

Is there any evidence that anyone has ever actually managed to see even Callisto as separate from Jupiter with the naked eye? I suspect not. RandomCritic 17:22, 10 February 2006 (UTC)

Somewhere in the last forty years of "Scientific American" (and yes, I realize that that's not a solid citation) there was an article about what constitutes a "scientific discovery". The thrust of the article was that to obtain proper scientific credit for a discovery, it was not enough to make the discovery per se, it was also essential to infer the importance of that discovery. It gave as one example that there exist "Indian" (as in Native Americans) drawings showing that they were able to observe the moons of Jupiter but attached no significance to them. I realize that this is all very vague. Old_Wombat (talk) 12:46, 28 June 2011 (UTC)

Shouldn't the history behind the discovery of the moons come later in the article? Probably, the list of moons should come earlier.

I have an issue with this part of the article - 'whether this was actually achieved by the Chaldeans remains a matter of speculation'. Since the word 'Chaldeans' leads to a disambiguation page, it could do with clarifying. Unfortunately I know nothing about the subject, and many of the potential meanings could be the correct one. Hopefully one of you knowledgable people will be abl;e to clear this up.

Pre-Galilean observations

While the Gan De connection, dubious as it is, at least has a real astronomical observation behind it, the "Horus" and "Marduk" conjectures do not appear to refer to astronomy at all - the citation given is totally inadequate - and don't belong in this article. So I'm deleting them. RandomCritic 20:14, 30 October 2006 (UTC)

There are some interesting notes on the possibility of naked eye observations of the Galilean moons in an archived Sky & Telescope article. Spaceman13 21:56, 9 May 2007 (UTC)

Hodierna names

I'm having some trouble with these. For one thing it's not clear where they actually appear -- I assume the Ephemerides, but I can't find this securely stated anywhere. For another, it's claimed that the names are for the "four Medici brothers" -- but which brothers? The names given are Principharus, Victipharus, Cosmipharus and Ferdinandipharus. But Cosimo II's brothers were Francesco, Carlo, and Lorenzo -- no Ferdinand among them; and his sons were Ferdinando II, Giancarlo, Matteo and Leopoldo -- without a Cosimo. Ferdinando II had a son Cosimo (III) who would have been a child at the time of the publication of the Ephemerides. And who do Principharus and Victipharus refer to? My best guess at this time is that Principharus stands for the late Medici ruler at the time Hodierna was writing, Cosimo II; Ferdinandipharus for his son, Ferdinando II; Cosmipharus for Ferdinando's son, Cosimo III; and Victipharus (some web sources have Victripharus, I'm not sure which is correct) for Ferdinando's wife, Vittoria della Rovere. But that's all guesswork. If anyone has access to Hodierna's Ephemerides, perhaps they could see if it contains an explanation? RandomCritic 10:51, 31 October 2006 (UTC) jkjlkjkl

Visible with the naked eye?

The following sentences seem to be contradictory: "All four Galilean moons can, in principle, be sighted without a telescope." "Other than the Moon, Ganymede is the only planetary satellite that can be seen by the naked eye, but still can only be seen in good conditions." So which is it? Colin M. 11:55, 23 May 2007 (UTC)

Merge Medician stars

Support:

• Of course, Medician stars should be merged into this article, as proposed in August 2007. Wikipedia cannot have 2 articles on the identical topic. Finell (Talk) 18:10, 28 October 2007 (UTC)
  • OK, the merge is done.--Pharos 17:23, 31 October 2007 (UTC)

Further work needed

Good work, and fast! To complete the merger, however, the subsection "Galileo" "Dedication" and the "Name" sections should be harmonized (there are fact conflicts) and duplication eliminated consolidated. Also, the facts and references should be harmonized with the relevant parts of Moons of Jupiter. Finell (Talk) 20:27, 31 October 2007 (UTC)

Yeah, and we should also explain the difference in dates of the discovery between the pre-merge version, "January 7, 1610", and the version from Medician stars, "December of 1609 or January of 1610", (which I went with because that version was obviously researched more carefully). If I recall correctly Jan. 7 may be one of a couple of exact dates that it could have been. This requires further reading to clarify.--Pharos 23:11, 31 October 2007 (UTC)

I did some editing and reorganizing, but did not consolidate the two sections. I don't have the book at hand, but any citations that are to Helden's introduction to Sidereus Nuncius should specifically cite the introduction in the footnotes to correctly attribute authorship. Finell (Talk) 01:21, 1 November 2007 (UTC)

Galileo Discovery Dates

Callisto (only one with discovery date reference), Io, and Europa are listed as discovered on January 7, 1610. But Ganymede is listed as discovered on January 11, 1610? Should all four Galilean moons be listed as discovered on the same date? Do we have a reference that shows Ganymede was truly discovered last, even though Callisto orbits further out and Io switched sides every day further confusing Galileo?
-- Kheider 19:02, 8 November 2007 (UTC)

Interior structure

There are some images in the article which show the interior sturcture of the moons. However, these are rather speculative. There is also no data on the different densities/compositions of the data which makes the images meaningless. There is no evidence to prove these structures are correct? How were they obtained? Polyamorph (talk) 10:57, 14 January 2008 (UTC)

Ok, more detail is provided on the interior structure in the individual articles relating to each moon. However, the images are meaningless on this page since the layers aren't labelled or explained. Considering this is already done in the individual moon pages, the interior structure images are superflous on this page and I will therefore remove them. Polyamorph (talk) 12:56, 14 January 2008 (UTC)

The models of the interiors are provided by CalTec's Jet Propulsion Laboratory. All the background information is directly accessible by clicking the images. All models of the interior of planets, including our own planet, are speculative - that is implied in the word 'model'. These are the latest authoritative models. The value of showing them in a comparative table is that it is possible to see how the interiors may vary with distance from the tidal heating effects of Jupiter. Io, in the centre, has no ice and a hot interior. The ice proportion increases as you move out. Only Callisto, the outermost one, remained so cold and solid that internal differentiation did not occur. This could all be left to individual articles - but then so could everything else about these four moons. We could, by such logic, delete the entire article. —Preceding unsigned comment added by 82.71.43.37 (talk) 20:35, 24 May 2010 (UTC)

The models are not explained in this specific article, which was my point. I disagree that the word 'model' implies speculation, one must strive to make the most accurate models possible based not on speculation but on verifiable and unambiguous experimental information. But that is for another discussion. If you feel that the models are useful to show how the interiors vary due to tidal heating etc then I agree that this is a very useful comparison. However, this really should be mentioned in the article prose with reference to the images, otherwise the reader doesn't know what comparison they are making. Which was my main point all along, without proper explanation the images are meaningless to the reader. Polyamorph (talk) 13:00, 28 June 2011 (UTC)

GA Review

This review is transcluded from Talk:Galilean moons/GA1. The edit link for this section can be used to add comments to the review.

I'm not really stalking you, comments to follow jimfbleak (talk) 05:32, 21 August 2008 (UTC)

Not stalking but replied in 15 mins? Anyways, let me know weather I should still put work into the article, or weather there is still moore to do. Nergaal (talk) 05:45, 21 August 2008 (UTC)

*Lead more distinctly than ever before in human history. – redundant words

• Thus, he spotted the Galilean moons – redundant and lost sentence, start previous sentence with The Galilean moons if necessary
• Geocentric theory – looks odd, why is Geocentric capped, but not theory?
• He named them after lovers of the god Zeus (the Greek equivalent of Jupiter): Io, Europa, Ganymede and Callisto, - You can’t say this twice in the lead!
• Discovery – position of image contra MoS, I think, if it’s left aligned, shouldn’t immediately follow heading, drop down a sentence. Also 4 in caption should be spelt out (also inconsistent with caption of lead image)

"also inconsistent with caption of lead image" ??? Nergaal (talk) 17:03, 21 August 2008 (UTC)

just meant that it "four" in the first caption and "4" in the second jimfbleak (talk) 18:27, 21 August 2008 (UTC)

* First two sentences both begin - As a result

• he only saw – should be he saw only
• Galileo also developed a method of determining longitude based on the timing of the orbits of the Galilean moons. – seems a bit lost – can it be expanded or melded into another paragraph?
• Dedication to the Medicis and his student's powerful family – don’t need to repeat student, esp as said to be former student before
• Name – first para repeats much of previous section, can this be improved?
• Ephemeredes – link or gloss please
• proper moon names.- do you need proper, or are there improper names?

I think proper refer to official names, and improper to informal names Nergaal (talk) 17:46, 21 August 2008 (UTC)

• in order from closest to Jupiter to farthest away – in order from closest (nearest?) if they are in order, last three words are redundant
• Table – any reason why this isn’t full-width and/or centred?

no Nergaal (talk) 18:06, 21 August 2008 (UTC)

• Visibility – I’ve tweaked a little, please check
• Io - many craters in pictures because it has many active volcanoes, 9. - many repeated, 9 should be spelt out
• Europa It suggested by Simon Marius, (sic) - this must be the fourth time we’ve been told he named the moons
• If any life exists in the water, it may be similar to Earth’s deep-sea creatures.- or it may not - this must have a source, or it’s just speculation
• Some theories are that Jupiter’s gravity is causing these markings, as one side of Europa is constantly facing Jupiter; volcanic water eruptions splitting the surface of Europa; and even geysers have been considered as a cause. The colour of the markings, reddish-brown, is theorized to be caused by sulfur, but scientists can't confirm it, because no data collection devices have been sent to Europa. –first sentence is almost unintelligible. Second is clumsy – better would be The reddish-brown colour may be caused by sulfur (why are we in British colour now incidentally?) cannot, not can’t
• Ganymede – does every sentence have to contain the moon’s name? – and there’s Simon Marius again. III (three) – an abomination, lose word.
• Callisto – see Ganymede
• image copyrights and refs OK

I haven't checked for any other AE/BE switches, I'll do that on a final read. jimfbleak (talk) 06:23, 21 August 2008 (UTC)

I will work on improving Ganymede and Callisto sometimes today. Nergaal (talk) 18:15, 21 August 2008 (UTC)

Should be ready now. Nergaal (talk) 22:44, 21 August 2008 (UTC)

I have expanded the members section significantly. Nergaal (talk) 23:17, 21 August 2008 (UTC)

GA review (see here for criteria) #It is reasonably well written. #:a (prose): b (MoS): #It is factually accurate and verifiable. #:a (references): b (citations to reliable sources): c (OR): #It is broad in its coverage. #:a (major aspects): b (focused): #It follows the neutral point of view policy. #:Fair representation without bias: #It is stable. #:No edit wars etc.: #It is illustrated by images, where possible and appropriate. #:a (images are tagged and non-free images have fair use rationales): b (appropriate use with suitable captions): #Overall: Pass/Fail:

I did a final tidy, see you at FAC! jimfbleak (talk) 05:43, 22 August 2008 (UTC)

Ganymede

There was a reference by the late Patrick Moore

"Ganymede, Prince of Troy".AT Kunene (talk) 10:09, 22 May 2013 (UTC)

Contradiction

The sections "Dedication to the Medicis" and "Name" contradict each other. Tad Lincoln (talk) 02:16, 2 April 2014 (UTC)

One says Cosimo made the suggestion. One says that Cosimo's secretary made the suggestion. — Preceding unsigned comment added by 92.26.0.234 (talk) 14:47, 22 September 2014 (UTC)

Archaic data

Our articles use refs that in turn cite Voyager and even pre-Voyager data. Especially for the physical parameters, we should be using Galileo data, shouldn't we? — kwami (talk) 23:46, 11 April 2014 (UTC)

Arcmin vs. arcsec

I changed something that said minutes of arc to read as seconds of arc and it was reverted. If it is indeed minutes then the citation on reference 44 should be changed to read arc min as well. TeigeRyan (talk) 23:42, 6 October 2014 (UTC)

Maybe I'm missing something, but the footnote says "631 arcsec = 10 arcmin". --JorisvS (talk) 08:16, 7 October 2014 (UTC)

I do not know if it was changed or if I was unclear, but it certainly seems clear now, so I am good. Thank you.TeigeRyan (talk) 03:30, 22 October 2014 (UTC)