Discovery and Naming:
Size, Mass and Orbit:
Since (like all of Uranus' moons) Oberon orbits the planet around its equatorial plane, and Uranus orbits the Sun almost on its side, the moon experiences a rather extreme seasonal cycle. Essentially, both the northern and southern poles spend a period of 42 years in complete darkness or complete sunlight - with the sun rising close to the zenith over one of the poles at each solstice.
Voyager 2:
Composition:
Interesting Facts:
NASA: Solar System Exploration - Oberon