Space · Moons

Stephano

A moon of Uranus — An outer retrograde irregular moon.

Quick facts

Parent planet

Uranus

Diameter (mean)

32 km

Mass

2.2 × 10¹⁶ kg
3e-07 Moon masses

Mean orbital radius

8,004,000 km

Orbital period

677.5 Earth days

Discovery year

1999

Discoverer

Brett J. Gladman, Matthew J. Holman et al.

Naming origin

Drunken butler in The Tempest

Surface conditions

Stephano is a retrograde outer irregular Uranian moon.

Missions and observations

Every Uranus-system mission has had an opportunity to image or characterize Stephano. The list below is the Uranus-system mission catalog; specific Stephano encounters are documented in mission archives.

Mission Year at Uranus Status

Voyager 2

NASA

1986 Completed

Naming etymology

Stephano was a drunken butler in Shakespeare's The Tempest. Adopted by the IAU in 2001.

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.

Last refreshed 2026-05-27 by Titan — new page.