Voyager 2 image of Umbriel taken on 24 January 1986. Image Credit: NASA/JPL via (Click image to enlarge)

Umbriel is the third-largest moon of the planet Uranus, with a mean radius of 585 km (363 miles) – about 0.34 times the size of our own Moon.

Umbriel was discovered in 1851 by William Lassell, at the same time that he discovered Ariel – the fourth largest moon of Uranus.

Umbriel was visited by the Voyager 2 spacecraft in 1986.

Umbriel is named after one of the spirits in the Tempest by William Shakespeare.

Astronomy, Cosmology, Space and Astrophysics