Ariel
Discovery
Discovered byWilliam Lassell
Discovered in1851
Orbital characteristics
Mean radius190,900 km
Perihelion
Aphelion
Eccentricity
Orbital period2.52 days
Inclination°
Satellite ofUranus
Physical characteristics
Equatorial diameter1160 km
Surface area4,200,000 km2
Masskg
Mean densityg/cm3
Surface gravitym/s2
Escape velocitykm/s
Rotation period2.52 days
Axial tilt°
Albedo
Surface temperature
minmeanmax
K K K
Atmospheric pressure0 kPa

Ariel is a moon of Uranus discovered in 1851 by William Lassell. Its composition is roughly 50% water ice, 30% silicate rock, and 20% methane ice, and it appears to have regions of fresh frost in places. Largely devoid of impact craters, Ariel appears to have undergone a period of intense geological activity that has produced a huge network of fault canyons and liquid water outflows over its surface.