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Mondas

Mondas is a fictional planet in the British science fiction television series Doctor Who. Mondas is the homeworld of the Cybermen, a race of cyborgs.

Mondas is first mentioned in the 1966 Doctor Who serial The Tenth Planet. This episode is also the first appearance of the Cybermen, a race that recurs in numerous Doctor Who stories. In The Tenth Planet, a New Zealand astronaut discovers a newly arrived planet near Earth, between the orbits of Mars and Venus. Later, a Cyberman informs the personnel of a nearby space station that this planet is the home of his people, the Mondasians. When the Cyberman mentions the planet's name, a Doctor Barclay inquires whether Mondas is not an ancient name for Earth (c.f. the Latin mundus). The Cyberman confirms, and claims that, billions of years ago, Mondas and Earth were twin planets until Mondas drifted into deep space. (In the mock-historical section of his book Cybermen, David Banks suggests that the Moon's orbit around Earth was the cause of Mondas' departure from orbit.)

The Cybermen began to send spaceships to conquer and colonise other planets, including Telos, where they pushed the native Cryons aside and established the "tombs" of the Cybermen, vast vaults where they could take refuge in suspended animation if needed.

Eventually, the Cybermen fitted a propulsion system to Mondas itself. This allowed them to pilot the planet through space, returning it to the solar system in 1986. The Cybermen invaded Earth while Mondas drew closer, draining Earth's energy to replace and supplement its own. However, the energy absorbed was too much, and Mondas disintegrated along with the Cyber forces on Earth.

The 2006 episodes " Rise of the Cybermen" and " The Age of Steel" introduce Cybermen who originated from an Earth in a parallel universe, rather than on Mondas. The Tenth Doctor alludes to Mondas when he explains that the Cybermen of his own universe started from a planet "just like" the Earth.