For example, when all oceans boil out on Earth in 500m years or so, it might become useless for colonization. Natural resources are way easier to get from asteroids/comets/moons.
(In addition you can also colonise between stars, of course.)
For example, when all oceans boil out on Earth in 500m years or so, it might become useless for colonization. Natural resources are way easier to get from asteroids/comets/moons.