Discovered by William Herschel in 1787, Oberon is named after the mythical king of the fairies who appears as a character in Shakespeare's A Midsummer Night's Dream.

The moon consists of approximately equal amounts of ice and rock, and is probably differentiated into a rocky core and an icy mantle.

The surface of Oberon, which is dark and slightly red in color, appears to have been primarily shaped by asteroid and comet impacts.

Oberon possesses a system of chasmata (graben or scarps) formed during crustal extension as a result of the expansion of its interior during its early evolution.

The Uranian system has been studied up close only once: the spacecraft Voyager 2 took several images of Oberon in January 1986, allowing 40% of the moon's surface to be mapped.

[14] For nearly fifty years following their discovery, Titania and Oberon would not be observed by any instrument other than William Herschel's,[15] although the moon can be seen from Earth with a present-day high-end amateur telescope.

[16] The names of all four satellites of Uranus then known were suggested by Herschel's son John in 1852, at the request of William Lassell,[17] who had discovered the other two moons, Ariel and Umbriel, the year before.

[22] In 1851, Lassell eventually numbered all four known satellites in order of their distance from the planet by Roman numerals, and since then Oberon has been designated Uranus IV.

This is the opposite of what is observed on other Uranian moons, where the leading hemisphere exhibits stronger water ice signatures.

[10] Meteorite impacts tend to sputter (knock out) ice from the surface, leaving dark non-ice material behind.

[29] However, the color asymmetry of Oberon is more likely caused by accretion of a reddish material spiraling in from outer parts of the Uranian system, possibly from irregular satellites, which would occur predominately on the leading hemisphere, similar to Saturn's moon Iapetus.

[33] Two primary classes of geological features dominate Oberon's surface: impact craters and chasmata ('canyons'—deep, elongated, steep-sided depressions[34] which would probably be described as rift valleys or escarpments if on Earth).

[36] Many large craters are surrounded by bright impact ejecta (rays) consisting of relatively fresh ice.

[8] The largest craters, Hamlet, Othello and Macbeth, have floors made of a very dark material deposited after their formation.

[8] The canyons' sides are probably scarps produced by normal faults[g] which can be either old or fresh: the latter transect the bright deposits of some large craters, indicating that they formed later.

The endogenic processes were mainly tectonic in nature and led to the formation of the canyons, which are actually giant cracks in the ice crust.

Some scientists hypothesized that they are of cryovolcanic origin (analogs of lunar maria),[35] while others think that the impacts excavated dark material buried beneath the pure ice (crust).

[42] The moons that formed in such a subnebula would contain less water ice (with CO and N2 trapped as clathrate) and more rock, explaining the higher density.

[43] After the end of formation, the subsurface layer cooled, while the interior of Oberon heated due to decay of radioactive elements present in its rocks.

[28] Further melting may have led to the separation of ice from rocks and formation of a rocky core surrounded by an icy mantle.