Umbriel (moon)

Umbriel
PIA00040 Umbrielx2.47.jpg
Umbriel as seen by Voyager 2 in 1986
Discovery
Discovered byWilliam Lassell
Discovery dateOctober 24, 1851
Designations
Pronunciationl/ UM-bree-əl[1]
Uranus II
AdjectivesUmbrielian
Orbital characteristics[2]
266 000 km
Eccentricity0.0039
4.144 d
Inclination0.128° (to Uranus's equator)
Satellite ofUranus
Physical characteristics
Mean radius
584.7 ± 2.8 km (0.092 Earths)[3]
4 296 000 km2 (0.008 Earths)[a]
Volume837 300 000 km3 (0.0008 Earths)[b]
Mass1.172 ± 0.135 × 1021 kg (2 × 10−4 Earths)[4]
Mean density
1.39 ± 0.16 g/cm3[4]
0.2 m/s2 (~ 0.023 g)[c]
0.52 km/s[d]
presumed synchronous[5]
0[5]
Albedo
  • 0.26 (geometrical)
  • 0.10 (Bond)[6]
Surface temp.minmeanmax
solstice[7]?~75 K85 K
14.5 (V-band, opposition)[8]
Atmosphere
Surface pressure
zero

Umbriel is a moon of Uranus found on October 24, 1851 by William Lassell. It was found at the same time as Ariel.

Name

The name "Umbriel" and the names of all four moons of Uranus then known were suggested by John Herschel in 1852 at the request of Lassell.[9] Lassell had earlier supported Herschel's 1847 naming scheme for the seven then-known moons of Saturn and had named his newly-found eighth moon Hyperion in accordance with Herschel's naming scheme in 1848. Umbriel is the 'dusky melancholy sprite' in Alexander Pope's The Rape of the Lock, and the name suggests the Latin umbra, shadow. The adjectival form of the name is Umbrielian.

It is also designated Uranus II.

Other Languages
Afrikaans: Umbriel (maan)
Alemannisch: Umbriel (Mond)
العربية: أومبريل (قمر)
azərbaycanca: Ambriel
تۆرکجه: آمبریل (قمر)
Bân-lâm-gú: Umbriel (oē-chheⁿ)
беларуская (тарашкевіца)‎: Умбрыель (спадарожнік Урана)
Deutsch: Umbriel
eesti: Umbriel
español: Umbriel
Esperanto: Umbrielo (luno)
فارسی: اومبریل
français: Umbriel (lune)
Gaeilge: Umbriel
Bahasa Indonesia: Umbriel
עברית: אומבריאל
Kreyòl ayisyen: Enbryèl
Bahasa Melayu: Umbriel (bulan)
Mìng-dĕ̤ng-ngṳ̄: Umbriel (ôi-sĭng)
Nederlands: Umbriel (maan)
norsk nynorsk: Uranusmånen Umbriel
oʻzbekcha/ўзбекча: Umbriyel
Plattdüütsch: Umbriel (Maand)
português: Umbriel
sicilianu: Umbriel
slovenčina: Umbriel (mesiac)
slovenščina: Umbriel (luna)
српски / srpski: Умбријел (сателит)
suomi: Umbriel
svenska: Umbriel
Türkçe: Umbriel (uydu)
اردو: امبریل
Tiếng Việt: Umbriel (vệ tinh)
粵語: 天衛二
中文: 天卫二