Mommur Chasma [SEP] located on astronomical body
Mommur Chasma
Mommur Chasma is the largest 'canyon' on the known part of the surface of Uranus' moon Oberon. This feature probably formed during crustal extension at the early stages of moon's evolution, when the interior of Oberon expanded and its ice crust cracked as a result. The canyon is an example of graben (rift valley) or scarp produced by normal fault(s). The chasma was first imaged by Voyager 2 spacecraft in January 1986.
The "Gazetteer of Planetary Nomenclature" states that Mommur Chasma is
in the Margaritifer Sinus quadrangle with Capri Chasma and Eos Chasma (in the south). The word "chasma" has been designated by the International Astronomical Union to refer to an elongate, steep-sided depression. Valles Marineris was discovered by and named for the Mariner 9 mission. Moving east from Noctis Labyrinthus, the canyon splits into two troughs, Tithonium and Ius Chasma in the south. In the middle of the system are very wide valleys of Ophir Chasma (north), Candor Chasma, and Melas Chasma (south