Titania | |
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Titania in color, taken by Voyager 2 | |
Date of discovery | January 11, 1787[1] |
Name of discoverer | William Herschel[1][2] |
Name origin | Queen of the fairies in the play A Midsummer Night's Dream by William Shakespeare |
Orbital characteristics | |
Primary | Uranus |
Order from primary | 17 |
Periuranion | 434,951 km[3] |
Apuranion | 436,869 km[3] |
Semi-major axis | 435,910 km[4] |
Orbital eccentricity | 0.0022[4] |
Sidereal month | 8.705872 da[4] |
Avg. orbital speed | 3.65 km/s[2] |
Inclination | 0.14°[4] to Uranus's equator |
Rotational characteristics | |
Sidereal day | 8.705872 da[4] |
Rotational speed | 0.006589 km/s[3] |
Axial tilt | 0°[4] |
Physical characteristics | |
Mass | 3.52*1021 kg[4] |
Density | 1710 kg/m³[4] |
Mean radius | 788.9 km[4] |
Surface gravity | 0.3781 m/s²[3] |
Escape speed | 0.768 km/s[2] |
Surface area | 7,820,847 km²[3] |
Mean temperature | 60 K[5] |
Composition | Water ice and rock[6] |
Color | Light brown-gray |
Albedo | 0.28[4] |
William Herschel discovered Titania and its next companion, Oberon, on January 11, 1787.[1]
Sir John Herschel, his son, gave to Titania the name of the queen of the fairies in William Shakespeare's comedy, A Midsummer Night's Dream.[1][7]
Titania is in a somewhat eccentric orbit around Uranus at an average distance of 435,910 km. Its sidereal month is about 8.71 Earth days.
Titania is in tidal lock with Uranus.
Titania has the greatest mass, diameter, and density of all the moons of Uranus. It is probably composed of water ice and rock, with a significantly higher proportion of rock than that of other moons of Uranus.[6]
Titania contains many fault-like interconnected valleys, an indication of significant tectonic activity.[2][6] Some of these valleys are hundreds of kilometers in length. Perhaps the longest of these valleys is a trench measuring 1,600 km in length. This trench is comparable in size to Ithaca Chasma on Tethys.
The surface is considered relatively "young" by uniformitarian standards. Some astronomers speculate that Titania was once liquid, and then froze, with the surface freezing before the interior.[6]
On September 8, 2001, at about 0200 UTC, Titania occulted the star Hipparcos #106829 (SAO 164538). Astronomers at the Observatoire Paris-Meudon used the data from this occultation to set an upper limit on the atmosphere of Titania, if it has one. That atmosphere can have no higher pressure than 0.03 microbar.[5][8]
Titania poses the same problem for uniformitarian astronomy as do all the other moons of Uranus: its orbit is inclined severely to the ecliptic, though not to Uranus' own equator. How the Uranian system came to have such an inclination has never been explained.
The only spacecraft to explore Titania has been Voyager 2. It approached to within 365,200 km of Titania on January 24, 1986, and took a small number of images.[9][10] No other detailed images are available.
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