Rings of Jupiter exist in Himalia's orbit. One possible explanation is that a small moon had crashed into Himalia and the force of the impact caused material to blast off Himalia. Jupiter's ring system was the third to be discovered in the Solar System, after those of Saturn and Uranus. It was first observed in 1979 by the "Voyager 1" space probe. It is composed of four main components: a thick inner torus of particles known as the "halo ring"; a relatively bright, exceptionally thin "main ring"; and two wide, thick and faint outer "gossamer rings", named after the moons of whose material
The Tenth Planet of malevolent cyborgs that became a recurring adversary in later "Doctor Who" stories. The "tenth planet" in the title makes reference to a fictional lost planet in Earth's Solar System; at the time of production, the Solar System was generally held to consist of nine planets, prior to the redesignation of Pluto as a minor planet. "The Tenth Planet" is an incomplete "Doctor Who" serial – one of many serials that were affected by the BBC's policy of wiping archived programmes in the 1960s and 70s. Only three of the four episodes are currently held in the BBC archives; the