re: colonization's always been a one-way trip
I remember seeing a special on the Solutreans, ancient Europeans that came accross the Atlantic along the shores of glaciers or ice that was connected to North America and Europe during the ice age. They knew that it was a one way trip or better yet, before technology, they didn't know or weren't sure that there was land on the other side, but they went anyways. They went anyways... did they know; why were they so sure to find land? That's remarkable to me. But, they did it anyways and succeeded, going about it blindfolded, but they succeeded.