major moon · moon of Uranus
Ariel
The brightest of Uranus's large moons, with a relatively young surface cut by long canyons and smooth, resurfaced valleys.
- Distance from Earth today
- 2.77 billion km18.52 AU · light: 2 h 34 min
- Distance from the Sun today
- 2.91 billion km19.43 AU
- As of
- 3 November 2026position from NASA/JPL orbital elements
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Diameter
- 1,158 km
- Mass
- 1,251 × 10¹⁸ kg
- Density
- 1,539 kg/m³
- Mean distance from the planet
- 190,929 km
- Orbital period
- 2.52 days
- Orbital eccentricity
- 0.0010
- Orbital inclination
- 0.0°
Source of the figures: JPL SSD – Planetary Satellites (public domain).
Discovery: 1851 – William Lassell
Description
Ariel is one of the five major moons of Uranus, discovered by William Lassell in 1851 and named after a spirit from Shakespeare's The Tempest. It has the brightest and apparently youngest surface of the group, with fewer large craters and a network of faults and canyons whose floors seem to have been smoothed by icy material welling up from below. Telescopic observations have detected carbon dioxide ice on its surface. Voyager 2 imaged roughly the southern half of Ariel during its 1986 flyby, the only close look so far.