Umbriel is a moon of Uranus, part of the Solar System in the universe. Uranus is a planet associated with the Sun, our star, and this space encyclopedia describes the moon’s identity and place in its planetary system.

Umbriel — A natural satellite of Uranus. Its physical properties and orbital motion are shown from the available catalogue and ephemeris data.

No object-specific chemical/elemental dataset has been verified and imported for this record. This does not mean none is publicly available. Appearance may be imagined; chemistry is not.

Discovery and designation
Umbriel was discovered in 1851. JPL credits W. Lassell. The name and discovery entry identify this particular satellite of Uranus; similarly named asteroids are separate objects.

Umbriel was discovered on Oct. 24, 1851 by English astronomer William Lassell.

Umbriel is the darkest of Uranus' largest moons. It reflects only 16 percent of the light that strikes its surface, a feature similar to the highland areas of Earth's Moon. Other Uranian moons are much brighter. The process by which Umbriel's ancient cratered surface was darkened remains a mystery.

Umbriel has a diameter of about 750 miles (1,200 kilometers). Images taken by Voyager 2 in 1986 revealed a curious bright ring about 90 miles (140 kilometers) in diameter on the moon's dark surface. It is unclear what created the distinctive ring, although it may be frost deposits associated with an impact crater.

Umbriel is named for a malevolent spirit in English poet Alexander Pope's 18th century poem "Rape of the Lock."