Physicist Stephen Hawking suggests that our ongoing efforts to colonize space could ultimately save humanity from extinction. As it stands, Earth is our only biosphere — all our eggs are currently in one basket. If something were to happen to either our planet or our civilization, it would be vital to know that we could sustain a colony somewhere else.
And the threats are real. The possibility of an asteroid impact, nuclear war, a nanotechnological disaster, or severe environmental degradation make the need for off-planet habitation extremely urgent. And given our ambitious future prospects, including the potential for ongoing population growth, we may very well have no choice but to leave the cradle.
We're obviously not going to get there overnight — but here's how we could do it.
Via Szabolcs Kósa