Umbriel is the darkest of Uranus's big moons, an old surface packed with craters.
Near its equator is a single bright ring about 130 km across, on the floor of a crater called Wunda. Nobody is sure what it is, perhaps a frost deposit.
Its name comes from a gloomy sprite in Alexander Pope's poem The Rape of the Lock.
If you stood here
Dark, cratered ground, about −200 °C, and a sky where Uranus hangs pale and huge.
- Width
- 1,169 km
- Goes round Uranus
- every 4.1 days
- One day
- The same: it always shows Uranus one face
- Temperature
- about −200 °C
- 70 kg on Earth weighs
- 1 kg here
