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
Sagan Planet Walk Sagan, Bill Nye, narrated a podcast tour of the Planet Walk in 2006 which can be accessed free by calling 703.637.6237 as you walk through the scale-model representation of the Solar System. The models of the Solar System, in order: The Sagan Planet Walk has inspired the creation of other scale-model Solar Systems in the United States. Sagan Planet Walk The Sciencenter's Sagan Planet Walk is a walkable scale model of the Solar System, located in Ithaca, New York. The model scales the entire Solar System—both planet size and distances between them—down to one five billionth of its actual size.