Wikipedia:Featured article candidates/Callisto (moon)

The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was promoted 01:32, 14 October 2007.

Callisto (moon)[edit]

This article is about one of the moons of planet Jupiter. It is comprehensive and well written. Callisto is a remarkable celestial body, and the article about it deserves Featured status.Ruslik 12:08, 4 October 2007 (UTC)[reply]

Support - a few of us have massaged the text along the way and I think we're over the line. I can't see anything obvious left out either. cheers, Casliber (talk · contribs) 13:16, 4 October 2007 (UTC)[reply]
~~Comment~~ Support — Overall a very good article and essentially FA quality.
- Most of the issues I saw concerned minor formating issues: uses of parentheses (which some people apparently find objectionable, apparently because of page reader software?) and space gaps around the em-dashes.
  Done I removed gaps and some parantheses. Ruslik 06:01, 5 October 2007 (UTC)[reply]
- ~~Some of the authors in the cite list have red links while others have none. Could the article be consistent in this and just remove those redlinks (unless you want to create pages for each author)?~~
  Done Ruslik 06:01, 5 October 2007 (UTC)[reply]
- ~~Note #45 needs more complete information in the citation.~~
  Done Ruslik 06:01, 5 October 2007 (UTC)[reply]
- ~~I thought a 'palimpsest' was a 'ghost crater'? Perhaps that could be wiki-linked and clarified?~~
  Done Added a note.Ruslik 06:01, 5 October 2007 (UTC)[reply]
- ~~In the 'Exploration' section, you should clarify that the radiation is low at the distance of Callisto from Jupiter (rather than from the Sun).~~
  Done Ruslik 06:01, 5 October 2007 (UTC)[reply]
Thanks.—RJH (talk) 17:32, 4 October 2007 (UTC)[reply]

Thanks for comments. Ruslik 06:01, 5 October 2007 (UTC)[reply]

I'm happy to support this article for FA. — RJH (talk) 16:10, 8 October 2007 (UTC)[reply]

Comment: I've given this article a quick copyedit but there are a few issues from what I've seen (I haven't looked over the whole article yet).

The main problem is that the lead goes into a lot of detail about many things that aren't covered in any more detail later on. E.g, the lead gives as much information about Callisto's lack of orbital resonance and tidal heating as the orbit section does. The lack of diffrentiation is mentioned three times, twice in the lead, once in the internal structure section. All three go into roughly the same amount of detail.

Done I limited the number of times the differentiation is mentioned in the lead to one instance. However differentiation is mentioned several times in 'Origin and evolution' subsection. As to orbital resonance, the only option is to remove it from the lead all together? Ruslik 05:36, 9 October 2007 (UTC)[reply]

The lead states baldly that Callisto has a subsurface ocean, while the subesequent sections state that this is merely a hypothesis.

Done Ruslik 05:36, 9 October 2007 (UTC)[reply]

"The exact composition of Callisto's rock is not known, but is probably close to the composition of L/LL type ordinary chondrites, which are characterized by less total iron, less metallic iron and more iron oxide." - I agree with the inserted text here. Less than what?

Done. Less than H-chondrites. Ruslik 05:36, 9 October 2007 (UTC)[reply]

(especially the dimensionless moment of inertia – 0.3549 ± 0.0042 determined during close fly-bys) - a little explanation of what is meant by this would be good.

Done added a note. Ruslik 05:36, 9 October 2007 (UTC)[reply]

I'll be back to look at the rest later. Serendi^podous 18:13, 8 October 2007 (UTC)[reply]

~~Comment/incipient~~ Support. It's great to see such a factual and well referenced article. For this reason, and also because it is an important Solar system body, the article deserves to be made Featured. I'm in the process of making various superficial copyedits, meanwhile, a few relatively small comments / questions / suggestions for improvement or clarification:

Intro: The purported ocean is mentioned as possible in the 2nd paragraph, while it is touted as unambiguously present in the 5th. Which is it? What about the core? — uncertain in the 2nd paragraph, in the 4th the slowness of heating prevented its formation, then later it is said that slow convection led to partial differentiation. So - has it differentiated or is this only "possible"? Has it got a core? or is it uncertain?

I think that I clarified these issues. The phrase "and thus the creation of a rocky core, and icy mantle" (which I removed) actually refered to events at the time of formation of Callisto, which did not in itself preclude the later core formation. So in this text I tried to say that Callisto failed to differentiate during formations, but probably differentiated partially after that due to the slow convection in interior, and therefore may have a small core. Ruslik 12:40, 9 October 2007 (UTC)[reply]

OK, that's good. I've just noticed, however, that over in Internal structure there is an echo of this issue — it's not explained what is the alternative of the ocean. In that case does the crust go all the way down to ~500km, is there a mantle, or does the poorly differentiated stuff start right below the 80-150 km thick crust? Deuar 13:00, 9 October 2007 (UTC)[reply]

The only alternative discussed seriously in the literature is a thick outer shell (~300 km) made of water ice on the top of mantle and possible core. Ruslik 13:20, 9 October 2007 (UTC)[reply]

DoneDeuar 15:12, 9 October 2007 (UTC)[reply]

Internal structure — "The radius of the core may be no more than 600 km" — what does this mean, exactly? e.g. that "it's about 600 km, if it's present at all", or is it that "the radius cannot be more than 600 km", etc.

It is the maximal radius compatible with moment of inertia and average density. Ruslik 13:20, 9 October 2007 (UTC)[reply]

DoneDeuar 15:12, 9 October 2007 (UTC)[reply]

Thanks. Deuar 12:14, 9 October 2007 (UTC)[reply]

Support. Bar a few samantic issues, I think this page is good enough to feature. Serendi^podous 15:44, 9 October 2007 (UTC)[reply]

Thanks to everyboby, I hope that the article will become featured soon. Ruslik 18:43, 9 October 2007 (UTC)[reply]

Comment First off, to the main editors of this article, congratulations on crafting an extremely comprehensive, well references article. The only concern that I had while reading was that several sections seem to use highly technical astronomical language that might cause a lay-reader to experience some confusion (e.g Atmosphere and ionosphere & Orbit and Rotation sections). I suppose it's unavoidable when dealing with a highly technical article - and one could always use the numerous blue links to clarify something they do not understand. Just an observation really. Kudos to the editors though! Wisdom89 16:02, 12 October 2007 (UTC)[reply]

Thanks for the comments. I tried hard to make the article understandable for a lay-reader, but there are limits on what I can do. Ruslik 19:28, 13 October 2007 (UTC)[reply]

I'll support with a few quibbles at this point. I was half done going over the prose before the FAC, but had been bloody slow and it was already great quality. The quibbles: this does need a go through for technical language. I don't think making an article understandable for a lay-reader is too difficult. Just ask how scarce the term is—endogenic is not a term that even an informed amateur is going to immediately understand, and is particularly over-technical in a lead. Duplicate blue links should also be audited for.

However, that's all another way of saying that this is truly information rich (as I've mentioned to Ruslik). I think it could be promoted now and the last "extra eyes" points could be done easily if editors watchlist it. (I uppercased the adjectival form consistently, for example—hope that doesn't bother, Ruslik.) Marskell 21:02, 13 October 2007 (UTC)[reply]

The above discussion is preserved as an archive. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.