Martian colony administrator threatens a Martian child. The Martians demand that the humans leave Mars, but a human doctor convinces them to reconsider. In Heinlein's 1956 novel "Double Star", humans have colonized the solar system, and a politician on Mars faces the civil rights issue of granting a native Martian species (who are second-class citizens) the right to vote. In Philip K. Dick's novel "Martian Time-Slip" (1964), a human colony on Mars is trying to cope with arduous environmental conditions. They treat an aboriginal race, whom they call "Bleekmen", with casual racism. In "The Three Stigmata of Palmer Eldritch" (1965), Mars
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