[JesseAldridge]

> "These planets are much, much too far away. Even in the very optimistic case of a livable planet that is not too far, say a few dozen light years...We are talking about hundreds of millions of days using the means we have available today. We must take care of our planet, it is very beautiful and still absolutely liveable."

That's actually a good point and one I hadn't really thought about.

The only way I can think of for humanity to get to these other planets would be to build a network of self sustaining space station colonies. And if we can do that we don't really need planets any more.