Scientists Are Contemplating a 1,000-Year Space Mission to Save Humanity

Relocating the human race to a more hospitable planet would mean that multiple generations would be born in-transit

Illustration: Janet Mac

After 200,000 years or so of human existence, climate change threatens to make swathes of our planet unlivable by the end of the century. If we do manage to adapt, on a long enough timeline the Earth will become uninhabitable for other reasons: chance events like a comet strike or supervolcano eruption, or ultimately — if we make it that long — the expansion of the sun into a red giant in around five billion years, engulfing the planet completely or at a minimum scorching away all forms of life. Planning for potential escape routes from Earth is, if not exactly pressing, then at least a necessary response to a plausible threat.

The most obvious destination is our neighbor Mars. We’ve already sent multiple probes there, and NASA is planning another moon landing in 2024 with the eventual plan of using it as a waypoint on a mission to Mars. Elon Musk’s Space X claims to be aiming for a crewed trip to Mars in the same year. But Mars is a desert planet, cold and barren, with no atmosphere save for a thin blanket of CO2. Sure, we could survive there, in protective suits and hermetically sealed structures, but…