Scientist have been spending the last 10 years or so developing an exit strategy for Earth's population (not all of them-think about that for a moment-only about 1-2 billion, not the present 7 billion...as the planet becomes unlivable due to the massive pollutants creating a greenhouse effect for the last 100 years since the Industrial Revolution- accelerated during the 1950s oil and gas boom. The exit would be the planet Mars-our closest neighboring planet. This is why that is not a good idea...and like so many other concepts of our destroy and abandon nature, hints at an endgame when we do not change that nature and reconnect to the vital sacredness of the planet and that authentic place within us..
http://earthsky.org/space/close-comet-flyby-plunged-mars-magnetic-field-into-chaos