On the One such event, which lasted for about six minutes, was observed on May 4, 2007, when Oberon occulted Umbriel.[18]. unknown dark material. Oberon is a dark moon of Uranus. Oberon, also designated Uranus IV, is the outermost major moon of the planet Uranus. Unbeknownst to scientists, 34 years ago Voyager 2 flew through a plasmoid, a giant magnetic bubble that may have been whisking Uranus’s atmosphere out to space. Oberon’s density is indicative of the fact that it contains equal proportions of water ice as well as a non-ice dense component. Oberon’s surface also has a number of chasmata or canyons that intersect the landscape. Voyager 2 spacecraft. [10], Oberon was initially referred to as "the second satellite of Uranus", and in 1848 was given the designation Uranus II by William Lassell,[11] although he sometimes used William Herschel's numbering (where Titania and Oberon are II and IV). These canyons are cracks on the crust of ice. Named by Herschel's son John in early 19th century for the king of the fairies in Shakespeare's "A Midsummer Night's Dream. covers the floors of many craters. [15] Oberon spends a significant part of its orbit outside the Uranian magnetosphere. [20] Further melting may have led to the separation of ice from rocks and formation of a rocky core surrounded by an icy mantle. [33] The impacts that accompanied accretion caused heating of the moon's outer layer. It is covered by numerous impact craters reaching 210 km in diameter. The more recent ones are brighter. [21] 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. center of the picture. [16] As a result, its surface is directly struck by the solar wind. Privacy Policy | Oberon Moon Facts. The 0° longitude Oberon is the second-darkest large moon of Uranus after Umbriel. Planetary scientist Geronimo Villanueva created the sunset simulations while building a tool for a possible mission to Uranus. The exact composition of the icy mantle is unclear. Site Manager: [27] Many large craters are surrounded by bright impact ejecta (rays) consisting of relatively fresh ice. Oberon In Color (Copyright Calvin J. Hamilton) So far the only close-up images of Oberon have been from the Voyager 2 probe, which photographed the moon during its flyby of Uranus in January 1986. [2] Scientists also believe there is a mountain that could be 20 km (12 mi) high on the moon. It was found on January 11, 1787 by William Herschel,[3] in the same year he found Titania.
[14] Its orbital period is around 13.5 days, coincident with its rotational period. Pictures of Oberon have been gathered by Voyager 2 probe during its flight past Uranus in January 1986. Size comparison of Earth, the Moon, and Oberon. The surface of Oberon, which is dark and slightly red in color, appears to have been primarily shaped by asteroid and comet impacts. Mommur Chasma is the most prominent canyon in Oberon. [15] Oberon's surface is the most heavily cratered of all the Uranian moons, with a crater density approaching saturation—when the formation of new craters is balanced by destruction of old ones. The name Oberon was derived from Oberon, the King of the Fairies in A Midsummer Night's Dream. A layer of liquid water may be present at the boundary between the mantle and the core. [26] A peak with a height of about 11 km was observed in some Voyager images near the south-eastern limb of Oberon,[28] which may be the central peak of a large impact basin with a diameter of about 375 km. [24], Scientists have recognized two classes of geological feature on Oberon: craters and chasmata ('canyons'—deep, elongated, steep-sided depressions[25] which would probably be described as rift valleys or escarpments if on Earth).
[20] The latter could be made of rock and carbonaceous material including heavy organic compounds. on on January 24, 1986, from a distance of 660,000 kilometers.