|
orbit: 265,980 km from Uranus
diameter: 1170 km
mass: 1.27e21 kg
Umbriel is a character in Alexander Pope's
The Rape of the Lock.
Discovered by Lassell in 1851.
Umbriel and Oberon appear quite similar though Oberon
is 35% larger. All of Uranus' large moons are a mixture of about
40-50% water ice with the rest rock, a somewhat larger fraction of rock than
Saturn's large moons such as
Rhea.
Umbriel's heavily cratered surface has probably been stable since its formation. It has far more and larger craters than do Ariel and Titania.
Umbriel is very dark; it reflects only about half as much light as Ariel, Uranus' brightest satellite.
... Uranus
... Ariel
... Umbriel
... Titania
... 
