http://www.msnbc.msn.com/id/45554617/ns/technology_and_science-space/#.Tt1iCGMk6nA We need to be able to get to a planet like this in way less than six hundred years. In case of an extinction level event, we need to be able to get to it in five.
Are you serious? Even if we could get there, how could we survive? The increase in gravity would crush a person.