Titania
astronomy
Titania, largest of the moons of Uranus. It was first detected telescopically in 1787 by the English astronomer William Herschel, who had discovered Uranus itself six years earlier. Titania was named by William’s son, John Herschel, for a character in William Shakespeare’s play A Midsummer Night’s Dream.
Titania orbits at a mean distance of 435,840 km (270,820 miles) from the centre of Uranus, which makes it the second outermost of the planet’s major moons. Its orbital period is 8.706 days, as is its rotational period. It is thus in synchronous rotation, keeping the same face toward the planet and the same face forward in its orbit. Its diameter is 1,578 km (980 miles), and it has a density of about 1.71 grams per cubic cm. Titania appears to be composed of equal parts water ice and rocky material; a small amount of frozen methane is probably present as well. (For comparative data about Titania and other Uranian satellites, see the table.)
name
mean distance from centre of Uranus (orbital radius; km)
orbital period (sidereal period; Earth days)*
inclination of orbit to planet's equator (degrees)**
eccentricity of orbit
rotation period (Earth days)***
radius (km)
mass (1020 kg)
mean density (g/cm3)
*R following the quantity indicates a retrograde orbit.
**Inclination values in parentheses are relative to the ecliptic.
***Sync. = synchronous rotation; the rotation and orbital periods are the same.
Cordelia
49,800
0.335
0.085
0.0003
20
Ophelia
53,800
0.376
0.104
0.0099
21
Bianca
59,200
0.435
0.193
0.0009
26
Cressida
61,800
0.464
0.006
0.0004
40
Desdemona
62,700
0.474
0.113
0.0001
32
Juliet
64,400
0.493
0.065
0.0007
47
Portia
66,100
0.513
0.059
0.0001
68
Rosalind
69,900
0.558
0.279
0.0001
36
Cupid
74,392
0.613
0.099
0.0013
5
Belinda
75,300
0.624
0.031
0.0001
40
Perdita
76,417
0.638
0.47
0.0116
10
Puck
86,000
0.762
0.319
0.0001
81
Mab
97,736
0.923
0.134
0.0025
5
Miranda
129,900
1.413
4.338
0.0013
sync.
235.7
0.66
1.2
Ariel
190,900
2.52
0.041
0.0012
sync.
578.9
13.5
1.67
Umbriel
266,000
4.144
0.128
0.0039
sync.
584.7
11.7
1.4
Titania
436,300
8.706
0.079
0.0011
sync.
788.9
35.2
1.71
Oberon
583,500
13.46
0.068
0.0014
sync.
761.4
30.1
1.63
Francisco
4,276,000
266.56R
(145.22)
0.1459
11
Caliban
7,231,000
579.73R
(140.881)
0.1587
36
Stephano
8,004,000
677.36R
(144.113)
0.2292
16
Trinculo
8,504,000
749.24R
(167.053)
0.22
9
Sycorax
12,179,000
1288.3R
(159.404)
0.5224
75
Margaret
14,345,000
1687.01
(56.63)
0.6608
10
Prospero
16,256,000
1978.29R
(151.966)
0.4448
25
Setebos
17,418,000
2225.21R
(158.202)
0.5914
24
Ferdinand
20,901,000
2887.21R
(169.84)
0.3682
10
Titania was observed close up on only one occasion, when the U.S. Voyager 2 spacecraft swiftly flew through the Uranian system in 1986. Spacecraft images show its surface to have many bright impact craters up to 50 km (30 miles) in diameter, but few large ones, along with trenches and a deep fault line extending roughly 1,600 km (1,000 miles). These and other related features strongly suggest the occurrence of internal geologic processes in the moon’s ancient past.
What's Your Reaction?
