Wikipedia:Featured article candidates/Umbriel (moon)/archive1

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 by Karanacs 17:44, 2 February 2010 [1].

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Umbriel (moon)

Nominator(s): Ruslik_Zero 20:26, 27 January 2010 (UTC)

• Featured article candidates/Umbriel (moon)/archive1

I am nominating this for featured article because, in my opinion, it is ready. This article is about one the five big moons of Uranus, the third candidate for the FA status. Ruslik_Zero 20:26, 27 January 2010 (UTC)

• Comments from Binksternet (talk) 22:36, 27 January 2010 (UTC)

• The Uranus template at the bottom lacks alt text for its image.

  This is a purely decorative image.

• Checklinks shows the URLs are all good.
• Dablinks shows two problems: one Setebos dab link, and one redirect which points back to article.

  I removed link to Setebos before the nomination, but the toolserver have not caught up (it currently shows the article does not exist). The second link is in a navbox.

• I don't think an en dash is needed in "co-rotates" and "co-rotation". A hyphen seems like enough.

  Fixed.

• This sentence needs a second em dash or some other choice of punctuation or parentheses: "Umbriel as well as another Uranian satellite—Ariel were discovered by William Lassell on 24 October 1851."

  Removed emdash.

• This sentence might be better with a colon swapped for the em dash: "The latter could include rock and heavy organic compounds—tholins."

  Enclosed tholins in parentheses.

• This sentence needs a second em dash or a different punctuation solution: "Opposite to what is observed for another dark Uranian moon—Oberon, the surface of Umbriel is slightly blue in color..."

  Replaced with comma.

• A colon for the em dash? "Scientists have so far recognized only one class of geological features on Umbriel—craters." Your call.

  I prefer emdash.

• Need the words "of" and "wide": "...from tens to hundreds kilometers."

  Rephrased.

• In the lede, the phrase "although there is evidence (canyons) of early endogenic processes" might be recast as "although the presence of canyons suggests early endogenic processes" or similar. The parentheses just don't seem necessary.

  Agree.

• Does "carbon rich material" need an adjectival hyphen, to make "carbon-rich material"?

  Agree.

• How about "from bombardment by charged particles" to replace your "caused by bombardment by charged particles"?

  Accepted.

• What did scientists conclude when they saw all the craters with no rays? Let the reader know.

  There is no specific meaning. It is just an observation, which may be important, but may not.

• The word atmosphere doesn't occur in the article. Please add something about the presence or absence.

  I added a parameter into infobox indication that surface pressure is zero (no atmosphere). However, it would be difficult to find a ref that unequivocally says this, because it is usually thought to be obvious. Ruslik_Zero 18:48, 29 January 2010 (UTC)

Rather than adding a whole subsection of the infobox to say that the moon has no atmosphere, it could be stated in the article in two or three words. Binksternet (talk) 19:23, 29 January 2010 (UTC)

I added something to the orbit section. Ruslik_Zero 18:54, 30 January 2010 (UTC)

• This sentence needs a bit of work: "Umbriel's most prominent surface feature is Wunda crater located near moon's equator, which has the diameter of about 131 km." How about "Near Umbriel's equator lies the most prominent surface feature: Wunda crater, which has a diameter of about 131 km."?

  Accepted.

• Why is there one instance of the word "Umbral" describing polygons? Is this supposed to be "Umbrielian"?

  I removed it, because "Umbral" (it is not a typo) is more often used in the phrase "Umbral material" referring to the dark material on the surface of Umbriel.

• "The polygons were identified from the accurate photometric measurements..." Which accurate measurements? Either state which, or remove "the".

  Clarified.

• This sentence can be trimmed slightly: "Its surface may be covered by a relatively thin layer made of a dark material, which was excavated by an impact or expelled in an explosive volcanic eruption." => "Its surface may be covered by a relatively thin layer of dark material excavated by an impact or expelled in an explosive volcanic eruption."

  Accepted.

• Which heavenly body is being referred to by "it"? Saturn? Uranus? Umbriel? "...it may have been relatively water-poor."

  Subnebula.

• The word ocean is misleading, since the concept is one of a subterranean water body: "A layer of liquid water (ocean) rich in dissolved ammonia..." Most people will visualize an ocean as being between the surface and the atmosphere.

  Ocean or subsurface ocean are terms widely used in literature, so it should remain (see ref 20, for example).

• Trim the redundancy: "no mission to this planet is planned in the foreseeable future" could become "no mission to this planet is planned", or "no further missions to this planet have been planned."

  Trimmed. Ruslik_Zero 11:16, 28 January 2010 (UTC)

Good article! Binksternet (talk) 23:48, 27 January 2010 (UTC)

• Support. Binksternet (talk) 15:35, 28 January 2010 (UTC)

• Comments -
  • Please spell out abbreviations in the references, I noted USGS but there may be others.

Otherwise, sources look okay, links checked out with the link checker tool. Ealdgyth - Talk 00:25, 28 January 2010 (UTC)

Spelled out. Ruslik_Zero 11:16, 28 January 2010 (UTC)

• Ongoing comments'

• This source talks about a "fluorescent Cheerio" and speculates that the darkness of the surface to the presence of methane and irradiation from Uranus (a whole page about Umbriel is missing from the preview, and I have no access to books). Is any of this worth keeping? :* The "bright ring" mentioned in the article is apparently about 150 km across, and is twice as reflective as Umbrial's average..here. Keep or not keep; up to you. • Ling.Nut 11:56, 28 January 2010 (UTC)
• More theories about coloration here. Up to yuo to decide if keepable.
• More about methane ice, magnetic fields etc. here. • Ling.Nut 12:13, 28 January 2010 (UTC)

Actually Wunda (fluorescent Cheerio) is already mentioned and various theories on origin of the dark material are already discussed. Ruslik_Zero 14:10, 28 January 2010 (UTC)

Yeah. I thought that someone might see the Cheerio nickname and try to find it here, to no avail. Also, the links provided a few new details, or so I thought. I didn't see the methane etc. bit in the explanations, forex... but as I said, you know more than I do. If you think it doesn't need to go in, then OK. • Ling.Nut 14:15, 28 January 2010 (UTC)

"fluorescent Cheerio" is a colloquial name, which is rarely used now. So, I do not think it should be mentioned in this article. On the other hand, it can be included in the article about Wunda (crater). As to methane, it is actually mentioned in the 'Origin' section. However methane is not thought to have been abundant in the Uranus' system, as the main carrier of carbon was probably carbon monoxide, not methane. In addition, methane ice is not stable on the surfaces of Uranian moons, and I doubt organic compounds can be produced from it. Ruslik_Zero 19:48, 28 January 2010 (UTC)

• Comments - Well written, clear and quite concise (even the heavier parts!). I tweaked some things myself to avoid writing them here. There is a reference to 'N₂', is this different to Nitrogen? One possible 'problem' I can see is unit conversions, I started adding additional conversion templates as there were some there already but stopped as the amount of numbers grew. Do the astronomy articles have an exemption from MOS:CONVERSIONS? Just wondering. I write articles on old British aircraft piston engines and had to add millimetres prior to FAC (although I think it looks daft personally). As a retired amateur astronomer this is not far off a 'support' vote from me. Nimbus (Cumulus nimbus floats by) 23:35, 28 January 2010 (UTC)

  N₂ is molecular nitrogen. (I added a clarification.) Ruslik_Zero 20:39, 29 January 2010 (UTC)

• Support - massaged the prose a bit early on, but needed to do less in the latter half of the article. No dealbreakers I can see. Casliber (talk · contribs) 02:32, 29 January 2010 (UTC)

One query - is antifreeze an accepted English word or would it be better to phrase as "compound with antifreeze properties"? Casliber (talk · contribs) 02:32, 29 January 2010 (UTC)

I think this is an accepted word, because we have an article about antifreeze. Ruslik_Zero 12:27, 29 January 2010 (UTC)

• Support • Ling.Nut 06:38, 29 January 2010 (UTC)

• Comments: The prose is reasonably well-polished. Some observations, though:

The adjectival form of the name is Umbrielian. Needs a citation; it doesn't appear to be covered by the reference at the end of the sentence.

If this is the case, the radius of the core (317 km (197 mi)) is about 54% of the radius of the moon, Parens within parens? I thought square brackets were used inside parentheses to indicate a parenthetical within a parenthetical. Firsfron of Ronchester 07:01, 29 January 2010 (UTC)

That would be my fault as I added the conversion yesterday. I've removed the conversion, noting that you can't use square brackets with the conversion template, could be done manually though. Nimbus (Cumulus nimbus floats by) 09:13, 29 January 2010 (UTC)

I removed Umbrielian as can not find a ref for it. Ruslik_Zero 20:39, 29 January 2010 (UTC)

Reference 17 is actually two references listed together, in bullet points. What's the reasoning behind the banding together of two references like this? They are papers from separate journal articles in different years by different authors. It looks strange to me. Firsfron of Ronchester 17:18, 30 January 2010 (UTC)

They are used to support the sentence about mutual occultations. They are used only one time each. So I think it is appropriate to group them. Ruslik_Zero 18:48, 30 January 2010 (UTC)

Well, I can't object over such a small detail, so I will...

• Support. Article looks terrific. Well-researched, well-sourced, and relatively clear to laymen. Well done, Ruslik. Firsfron of Ronchester 16:46, 31 January 2010 (UTC)
• Support: This article provides a comprehensive look at the current state of knowledge of this rather forgotten moon of Uranus, compared to its more geologically active neighbors, Ariel and Miranda. In terms of missing content, I would suggest adding some mention of the source of names for Umbriel's craters (dark spirits for mythologies and folklore around the world, IIRC). I too am a bit confused by the bit about "umbral material". Do you mean a lag deposit, like on Callisto and Iapetus? The wikilink used does not provide useful context, but from the description in the article, I think you mean lag deposit. --Volcanopele (talk) 10:47, 31 January 2010 (UTC)

  I added information about crater names. As to 'Umbral material', it is mentioned in Buratti 1991, which in turn refers to Croft 1991. It means the dark material, which covers the surface of Umbriel, especially that of dark polygons. It is not lag a lag deposit, because no such deposits are known on Umbriel (due to poor resolotion of images—5 km is not enough). Ruslik_Zero 12:46, 31 January 2010 (UTC)

• Support with comments. I gave it a read through and it looks to be of FA quality. I only found a few minor concerns:
  • "Both northern and southern hemispheres spend 42 years in complete darkness, and another 42 years in continuous sunlight." Should this say "poles" rather than "hemispheres"? For the full hemispheres, I assume the illumination is phased over the 84 year period.

    Changed to 'poles'.

  • "Other plausible candidates for the dark surface materials include rock, various salts and organic compounds." This follows a discussion of carbon dioxide, which I think forms a transparent ice. So is the "Other" appropriate here? Doesn't this sentence belong in the prior paragraph?

    I removed this sentence as it duplicated the previous paragraph.

  • "The moon's surface shows a strong opposition surge..." Could the cause of this be briefly explained for lay people?

  Thank you.—RJH (talk) 20:16, 31 January 2010 (UTC)

  I added an explanation of the 'opposition surge'. Ruslik_Zero 16:05, 1 February 2010 (UTC)

  Thanks.—RJH (talk) 20:11, 1 February 2010 (UTC)

• Support, I couldn't see anything significant not already addressed Jimfbleak - talk to me? 08:13, 2 February 2010 (UTC)
• Images - both images from US government sources and properly stated as so with appropriate sources listed. Ealdgyth - Talk 16:48, 2 February 2010 (UTC)

The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.