From Simple English Wikipedia, the free encyclopedia
Umbriel
is a moon of
Uranus
found on October 24, 1851 by
William Lassell
. It was found at the same time as
Ariel
.
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
.
So far the only close-up images of Umbriel are from the
Voyager 2
probe, which made observations of the moon during its Uranus flyby in January, 1986. During the flyby the southern hemisphere of the moon was pointed towards the
Sun
so only it was studied.
Umbriel's surface is the darkest of the Uranian moons, and reflects only about half as much light as
Ariel
, Uranus' brightest moon. It has far more and bigger craters than do
Ariel
and
Titania
and is also the least geologically active.
[10]
It is mostly made of
water
ice, with the balance made up of
silicate
rock, and other ices such as
methane
. Methane can break down and form reddish-black organic compounds such as
tholins
when
bombarded
by high-energy particles.
[11]
Near-IR spectra of Ariel and Umbriel clearly show that water ice dominates the spectra of these objects.
[12]
Craters on Umbriel are named after many different
demons
from various mythologies.
- ↑
Surface area derived from the radius
r
:
.
- ↑
Volume
v
derived from the radius
r
:
.
- ↑
Surface gravity derived from the mass
m
, the
gravitational constant
G
and the radius
r
:
.
- ↑
Escape velocity derived from the mass
m
, the
gravitational constant
G
and the radius
r
:
.
- ↑
"Umbriel"
. Dictionary.com
. Retrieved
2010-01-14
.
- ↑
"Planetary Satellite Mean Orbital Parameters"
. Jet Propulsion Laboratory, California Institute of Technology.
- ↑
Thomas, P. C. (1988).
"Radii, shapes, and topography of the satellites of Uranus from limb coordinates"
.
Icarus
.
73
(3): 427?441.
Bibcode
:
1988Icar...73..427T
.
doi
:
10.1016/0019-1035(88)90054-1
.
- ↑
4.0
4.1
Jacobson, R. A.; Campbell, J. K.; Taylor, A. H.; Synnott, S. P. (June 1992).
"The masses of Uranus and its major satellites from Voyager tracking data and earth-based Uranian satellite data"
.
The Astronomical Journal
.
103
(6): 2068?2078.
Bibcode
:
1992AJ....103.2068J
.
doi
:
10.1086/116211
.
{{
cite journal
}}
: CS1 maint: multiple names: authors list (
link
)
- ↑
5.0
5.1
Smith, B. A.; Soderblom, L. A.; Beebe, A.; Bliss, D.; Boyce, J. M.; Brahic, A.; Briggs, G. A.; Brown, R. H.; et al. (4 July 1986).
"Voyager 2 in the Uranian System: Imaging Science Results"
.
Science
.
233
(4759): 43?64.
Bibcode
:
1986Sci...233...43S
.
doi
:
10.1126/science.233.4759.43
.
PMID
17812889
.
S2CID
5895824
.
{{
cite journal
}}
: CS1 maint: multiple names: authors list (
link
)
- ↑
Karkoschka, Erich (2001).
"Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope"
.
Icarus
.
151
(1): 51?68.
Bibcode
:
2001Icar..151...51K
.
doi
:
10.1006/icar.2001.6596
.
- ↑
Grundy, W. M.; Young, L. A.; Spencer, J. R.; Johnson, R. E.; Young, E. F.; Buie, M. W. (October 2006).
"Distributions of H
2
O and CO
2
ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations"
.
Icarus
.
184
(2): 543?555.
arXiv
:
0704.1525
.
Bibcode
:
2006Icar..184..543G
.
doi
:
10.1016/j.icarus.2006.04.016
.
S2CID
12105236
.
{{
cite journal
}}
: CS1 maint: multiple names: authors list (
link
)
- ↑
"Planetary Satellite Physical Parameters"
. NASA/JPL
. Retrieved
June 6,
2010
.
- ↑
(in German)
Beobachtungen der Uranus-Satelliten
Adsabs.harvard.edu
Retrieved on 06-01-07
- ↑
Arnett, William A. (Aug 25, 2006).
"Umbriel"
. The Nine Planets
. Retrieved
2007-11-09
.
- ↑
Overbye, Roger (April 1986).
"Voyager was on target again; in the latest unmanned triumph, Voyager 2 surveyed Uranus and sent back a real bull's-eye"
. Discover
. Retrieved
2007-11-09
.
- ↑
Dumas, Christophe; Smith, Bradford A.; Terrile, Richard J. (2003).
"Hubble Space Telescope NICMOS Multiband Photometry of Proteus and Puck"
.
The Astronomical Journal
. 126 (2003) (2): 1080?1085.
doi
:
10.1086/375909
.
S2CID
122085744
.
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permanent dead link
]