← ALL BRIEFINGS

Ariel

← ALL CELESTIAL BODIES
Credit: NASA/JPL Public domain — NASA Media Usage Guidelines
MOON

Ariel

The brightest and seemingly youngest of Uranus's major moons — crossed by a network of rift valleys.

Orbits Uranus
  • Highest albedo of any Uranian moon u2014 appears bright and young.
  • Extensive system of rift canyons and graben floors resurfaced by possible cryovolcanism.
  • Mixed water-ice and rocky composition.

Physical Properties

579 km
1.251e21 kg
1.592 g/cm³
0.249 m/s²
60.48 h
0.53
60 K

Orbit

Uranus
191,020 km
0.0012
0.041°
2.52 d

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: 2026-04-18 18:19:25.

Ariel is the fourth-largest moon of Uranus and has the brightest surface of the Uranian moons, suggesting a relatively young crust. Voyager 2 imagery revealed an extensive network of deep rift valleys and smooth “graben floors” inside canyon systems — strong evidence of geologic activity, possibly cryovolcanic resurfacing, early in Ariel’s history.