>If something planet-scale happens while we wait on a single planet, the entire species would not make it On the other hand, the list of disasters that would l

>If something planet-scale happens while we wait on a single planet, the entire species would not make it On the other hand, the list of disasters that would leave Earth less inhabitable than Mars without also destroying any Mars colony is pretty rare. If human survival is the primary goal, it might be best to work on perfecting that sort of self contained habitat somewhere in the remote parts of Earth.