Oberon
Moon· orbits Uranus
Oberon is the outermost large moon of Uranus — an ancient, heavily cratered surface of ice and rock, with dark deposits on some crater floors.
Open in 3D viewSee Oberon in the live, interactive 3D map
Key facts
Mass
3.08 × 10²¹ kg
0.0419 Moon masses
Radius
761 km
44% of our Moon's radius
Surface gravity
0.354 m/s²
4% of Earth's
Day length
13.5 days
Orbit around Uranus
13.46 Earth days
Science
Physical
- Mass
- 3.08 × 10²¹ kg · 0.0419 Moon masses
- Radius
- 761 km · 44% of our Moon's radius
- Density
- 1,664 kg/m³ · 1.7× water
- Surface gravity
- 0.354 m/s² · 4% of Earth's
- Escape velocity
- 734 m/s · 7% of Earth's
Orbit around Uranus
- Distance from Uranus
- 790,036 km
- Orbital period
- 13.5 days
- Eccentricity
- 0.002
- Inclination
- 0.10 °
Rotation
- Rotation period
- 13.5 days
- Tidal locking
- Tidally locked to its parent
Temperature
- Mean
- 75 K (-198 °C)
Composition
- Bulk composition
- Water ice and rock in roughly equal measure, with dark reddish material in some craters.
Radiation & temperature
- Insolation
- 0.00264 S⊕ · 1/378 of the sunlight Earth receives
- Bond albedo
- 0.14 · reflects 14% of incoming sunlight
- Equilibrium temperature
- 61 K (-212 °C)
- Measured mean temperature
- 75 K (-198 °C)
- Greenhouse warming
- +14 K
Discovery & history
- Discovered
- January 11, 1787
- By
- William Herschel
- Method
- Visual discovery (telescopic)
- Name
- Oberon, king of the fairies in Shakespeare's 'A Midsummer Night's Dream'.
Herschel found Oberon, the outermost large moon of Uranus, on the same night as Titania in 1787. Its old, cratered surface is dotted with dark patches and a lone mountain that juts some 11 km above the limb.
Images
Images from open archives · credit shown per image