Oberon (moon) geological feature on Oberon: craters and chasmata ('canyons'—deep, elongated, steep-sided depressions which would probably be described as rift valleys or escarpments if on Earth). 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. This high number of craters indicates that Oberon has the most ancient surface among Uranus's moons. The crater diameters range up to 206 kilometers for the largest known crater, Hamlet. Many large craters are surrounded by bright impact ejecta (rays) consisting of relatively fresh ice. The
Devil's Planet Devil's Planet "Devil's Planet" is the twenty-second episode of the second series of the British sci-fi television series "" (and the forty-sixth overall episode of the programme). The screenplay was written by Michael Winder; the director was Tom Clegg. The original title of the episode was "Devil's Moon". The final shooting script is dated 9 September 1976 and live-action filming began on Monday 1 November 1976 lasting through to Thursday 18 November 1976. The episode was first broadcast in the U.K. on 1 September 1977. 2306 days after leaving Earth orbit, the Moon is passing a solar system containing a