[GonzoGOP]

Actually a Ram-augmented interstellar rocket could make it up to speeds of almost .3 C. At that rate Gliese 581g would be well within the rage of a two or three generation starship. Since a very large starship is little different than a space colony people of the future, who will likely have grown up in space colonies, would not consider this such a big deal.

We are talking dim distant future here. But hey Columbus opened the trade route to America in 1492. And the Jamestown colony wasn't founded until 1607. So a 115 year gap between discovery of a destination and the first tentative attempts at colonization isn't unprecedented. But we won't be any reason for going to other stars until we have completed colonization of this solar system. And that will take someplace between thousands of years or if we stay at the current pace hundreds of thousands of years. Like I said dim distant future.

[plain talk]

But we won't be any reason for going to other stars until we have completed colonization of this solar system

You raise a good point. We are talking dim distant future as you say anyway and probably long before we attempt to reach a star we would probably inhabit Mars which would be a massive job in itself.

Also - even if our best remote tests indicate a planet circling a star is a perfect clone we could find that it might require a self-contained atmospheric dome anyway to survive anyway because of deadly compounds in the atmosphere, deadly radiation or who knows what. And those things might not be fully understood until a crew reached that planet. This means they would have to plan for worst case scenario and come equipped to not fully rely on the atmosphere. An expedition to a star likely comes long after man has destroyed Mars and every other possible place of habitation in this solar system or has to flee other groups of man just to survive.