Talk:Umbriel (moon)

Untitled
According to The Royal Shakespeare Company, this is pronounced [UM-bree-el].

Orphaned references in Umbriel (moon)
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Umbriel (moon)'s orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.

Reference named "usgs": From Margaret (moon):  From Ammonia:  From Moons of Haumea:  From Carbon:  From Verona Rupes:  From Wunda (crater):  

Reference named "orbit": From Callisto (moon): </li> <li>From Ganymede (moon): </li> </ul>

Reference named "Smith1986":<ul> <li>From Uranus: </li> <li>From Climate of Uranus: </li> </ul>

I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 18:41, 26 September 2009 (UTC)

Night sky on Umbriel
Out of curiousity, I did a quick, back-of-the-envelope comparison between Uranus as seen from Umbriel and the Moon as seen from the Earth at night. If my calculations are correct (which may be a big if ;-), the half phase Uranus reflects more than five times as much solar energy as seen from Umbriel than the first quarter Moon reflects as seen from Earth. That's despite the fact that Uranus is much further from the Sun than is the Earth/Moon system; Uranus compensates with a much bigger angular area as seen from Umbriel and a higher albedo than the Moon. So the night sky on Umbriel may not be all that dark, at least when Uranus is in the sky. Probably too much like OR for this article though. :-) &mdash;RJH (talk) 20:20, 1 February 2010 (UTC)
 * It is not merely a curiosity. See and . Ruslik_ Zero  20:32, 1 February 2010 (UTC)
 * Interesting. That work reminds me a little of the Japanese image of the Shackleton (crater) made entirely from light reflected off the rim. Thanks.&mdash;RJH (talk) 22:49, 6 February 2010 (UTC)

"Leading/Trailing Hemisphere" unexplained
After doing a wiki search for either "Leading" or "Trailing" hemispheres, I am unable to find an explanation by wikipedia for these phrases, or for that matter this article- adequately explaining the definition or difference of either of these terms. It would be good to clarify the terms or more pointedly add such terms to the wikilinked article Sphere, or some appropriate area, along with a redirect for either of the terms and addition to the article Hemisphere. AnAnthro (talk) 07:21, 3 April 2011 (UTC)
 * We have an article on Tidal locking, would probably fit in there. GermanJoe (talk) 09:15, 3 April 2011 (UTC)
 * Good choice; however, this would not only mean adding to the lead of Tidal locking to incorporate both leading and trailing hemispheric planetary science jargon (as well as later references), but the rather large task of wikilinking the terms peppered throughout many natural satellite articles, such as Callisto (moon) and Thebe (moon) along with their corresponding geological features such as Masubi (volcano) and Xanadu (Titan). Dozens if not hundreds of articles would require to be wikilinked. AnAnthro (talk) 11:20, 3 April 2011 (UTC)
 * It's ca. 66 articles for "trailing hemisphere" and ca. 55 for "leading hemisphere" with a (hopefully) huge overlap between both (with Google's extended search for the exact phrase in the specific location en.wikipedia.org). Not sure, if this catches all hits, but it's a first estimate. GermanJoe (talk) 11:59, 3 April 2011 (UTC)
 * Perhaps the mundane task of wikilinking ≈121 articles could be automated, using AWB for example. I do not have experience with the program or automating edits, however. AnAnthro (talk) 12:17, 3 April 2011 (UTC)

Polygons?
The caption on the blue-colored photo of Umbriel mentions polygons, and apparently has since the photo was added to the article. However, the article itself says that the only feature type identified on the moon is craters. When I look at the photo, I see some craters that are vaguely polygonal. If these are actually polygonal (i.e. their appearance isn't an artifact of the photograph or wishful thinking) it would be good to mention something in the article, even if it's just "Umbriel has some features which are polygons. Scientists are unsure what causes these shapes", along with an appropriate referrence, of course. Wabbott9  Tell me about it....  22:16, 29 June 2011 (UTC)

External links modified (February 2018)
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I have just modified one external link on Umbriel (moon). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20090826163708/http://solarsystem.nasa.gov/planets/profile.cfm?Object=Ura_Umbriel to http://solarsystem.nasa.gov/planets/profile.cfm?Object=Ura_Umbriel

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Cross checking numbers for density and surface gravity
If you know the Radius, Surface Area, and Volume, and the Mass, then the density, and the surface gravity are simple calculations. Density is Mass / Volume and it is more than that listed. it should be around 1.522. The gravity is between 0.24 and 0.25.

To find the surface gravity use Radius(km) X Density (kg/m^3)/ 3,582,688 = __________ m/sec^2. 584.7 X 1522 / 3,582,688 = 0.248 393, which is between 0.24, and 0.25.98.245.216.62 (talk) 21:24, 23 October 2020 (UTC)