If and when Earth is no longer able to sustain human life, where should we go? NASA says that a colony could be dug several feet below the surface of our moon (with a cover to protect residents from high-energy cosmic radiation, which can damage our DNA and lead to cancer).
Or we could head for the resource-rich moons of Jupiter, Saturn, Uranus and Neptune. Mars is very Earth-like, with enough carbon in its soil to grow plants, and daytime temperatures that reach 70°F. And that’s only the start of our options. Popular Science explores:
Earth won’t always be fit for occupation. We know that in two billion years or so, an expanding sun will boil away our oceans, leaving our home in the universe uninhabitable—unless, that is, we haven’t already been wiped out by the Andromeda galaxy, which is on a multibillion-year collision course with our Milky Way. Moreover, at least a third of the thousand mile-wide asteroids that hurtle across our orbital path will eventually crash into us, at a rate of about one every 300,000 years.