Oberon
What is Oberon?
Moons· Diameter 1,523 km. The outermost of Uranus's large moons, with an old, heavily cratered surface, a mountain about 11 km high, and dark material on the floors of its big craters.
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Orbit and size
| Diameter | 1,523 km |
|---|---|
| Distance from Uranus | 583,500 km |
| Orbit | 13.5 d |
| Note | 11-km mountain, dark crater floors |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Parent planet and sibling moons
Hamlet crater and the dark floors of Oberon
Oberon's features are named after male characters from Shakespeare's plays. The largest crater, 206 km across, is Hamlet, and around it lie craters named Othello, Macbeth, Lear and Romeo. The largest canyon, Mommur Chasma, takes its name from the forest where the fairy king Oberon lives in an old French tale.
The floors of Hamlet and other large craters hold patches of unusually dark material, and no one yet knows where it came from. One idea is that impacts broke through the crust and let dark material from inside rise up. Another is that ice volcanoes erupted a dark slush. Voyager 2 photographed Oberon from about 470,000 km away, so its pictures are blurry, which makes it hard to decide.
Oberon and Titania went without names for 65 years after they were found. In 1852 John Herschel, William Herschel's son, gave them the names they have today. After finding the two moons, William Herschel announced four more, but other astronomers could never find them, and they were eventually judged to be mistakes.
The moon in depth
William Herschel discovered Oberon on 11 January 1787, the same night he found Titania. It is named for the fairy king in Shakespeare's play A Midsummer Night's Dream. At 1,523 km across it is a little smaller than Titania, making it the second-largest moon of Uranus. It orbits 583,500 km from the planet and takes 13.5 days, about two weeks, to go around once.
In 1986 Voyager 2 could photograph only Oberon's southern half, because that was the side facing the Sun at the time. The pictures showed a surface packed with craters. Many craters mean the surface has not been renewed for a very long time. On the moon's edge a mountain about 11 km high stood out in silhouette, taller than Mount Everest at about 8.8 km.
Follow Uranus in the orbit view to see Oberon moving slowly on the outermost path of the five large moons. For much of its orbit it travels outside the region controlled by Uranus's magnetic field. Because Uranus orbits the Sun tipped on its side, one half of Oberon also gets decades of sunlight while the other half spends decades in darkness.
Frequently asked
- How big is Oberon?
- The diameter of Oberon is 1,523 km.
- How far is Oberon from Earth?
- The distance from uranus of Oberon is 583,500 km.
- What is notable about Oberon?
- The note of Oberon is 11-km mountain, dark crater floors.
- Which planet does Oberon orbit?
- Oberon orbits Uranus.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.