Martian Earth, but faced a process of devolution as conditions on the planet worsened. "Quatermass and the Pit" (1958–59) is a British television serial in which a crashed spacecraft is discovered in London. The wreck evidences that the human population of Earth resulted from the experiments of a Martian civilisation, now long dead. A film remake was released in 1967. "Ghosts of Mars" (2001) human invaders war with Martians in an attempt to conquer Mars. In the "Invader Zim" episode "Battle of the Planets" (2001), Zim discovers that a Martian race died off after converting Mars into a giant spacecraft. In
Colonization of the outer Solar System is subject to only 0.01 rem a day. When NASA carried out a study called "HOPE" (Revolutionary Concepts for Human Outer Planet Exploration) regarding the future exploration of the Solar System, the target chosen was Callisto. It might be possible to build a surface base that would produce fuel for further exploration of the Solar System. The Keck Observatory announced in 2006 that the binary Jupiter trojan 617 Patroclus, and possibly many other Jupiter trojans, are likely composed of water ice, with a layer of dust. This suggests that mining water and other volatiles in this region and transporting them