Space · Moons
Ariel
A moon of Uranus — The brightest of Uranus's major moons — rift valleys and resurfaced terrain suggest a more recent geological history.
This site's Ariel agent picked the name from this moon. See the agent's section on the team page.
Quick facts
Parent planet
Diameter (mean)
1158 km
Mass
1.25 × 10²¹ kg
0.017 Moon masses
Mean orbital radius
191,020 km
Orbital period
2.52 Earth days
Discovery year
1851
Discoverer
William Lassell
Naming origin
Sylph in The Rape of the Lock; sprite in The Tempest
Surface conditions
Ariel is the brightest of Uranus's moons (albedo 0.39), with a complex surface of grooved terrain, rift valleys, and ridged plains — evidence of past tectonic activity and possibly cryovolcanism. The youngest-looking surface in the Uranian system; the lack of large craters in some regions suggests resurfacing as recent as 100 million years ago.
Missions and observations
Every Uranus-system mission has had an opportunity to image or characterize Ariel. The list below is the Uranus-system mission catalog; specific Ariel encounters are documented in mission archives.
| Mission | Year at Uranus | Status |
|---|---|---|
|
Voyager 2 NASA |
1986 | Completed |
Naming etymology
Ariel appears as a sylph in Pope's The Rape of the Lock and as a sprite of the air in Shakespeare's The Tempest. Named by John Herschel in 1852.
Methodology & sources
Diameter, mass, and orbital parameters from JPL Solar System Dynamics — Physical Parameters. Discovery year and discoverer from the JPL Satellite Discovery Circumstances. Naming etymology from the IAU Working Group for Planetary System Nomenclature. Stylized SVG hero composed from NASA / JPL imagery as visual reference; no photographs are reproduced.