Umbriel

The dark, ancient, heavily cratered Uranian moon with the enigmatic Wunda crater.

Orbits Uranus

Darkest of Uranus's five major moons u2014 albedo just 21%.
Features the 131 km Wunda crater whose floor shines unusually bright.

About Umbriel

Umbriel is the third-largest moon of Uranus and has the darkest, most ancient surface of the five major Uranian moons. Its low albedo points to a coating of dark organic-rich material. Umbriel’s signature feature is Wunda, a 131 km crater whose remarkably bright floor has never been satisfactorily explained.

Live · 3DSee Umbriel in the Live 3D Solar SystemFly to Umbriel and explore its orbit among the planets, moons & spacecraft in a full-screen interactive view.Launch 3D view

Physical Properties

Mean radius585 km

Mass1.275e21 kg

Density1.39 g/cm³

Surface gravity0.252 m/s²

Rotation period99.46 h

Bond albedo0.21

Mean temp75 K

Orbit

OrbitsUranus

Semi-major axis266,000 km

Eccentricity0.0039

Inclination0.128°

Orbital period4.144 d

Gallery

Hand-picked mission imagery of Umbriel sourced from NASA and partner archives. Click any photo for full resolution and source attribution.

Uranus's dark moon Umbriel, from Voyager 2. NASA/JPL-Caltech · Public Domain u2014 NASA Media Usage Guidelines

Imagery on this page is provided by the original mission teams. Full attribution terms: Image Rights & Credits.

Sources & Further Reading

Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-06-08 01:37:02.