> and ultimately where we came from on this earth.

I will always hope that we find some clue which suggests humans came from somewhere other than Earth. That would probably be the second best thing, after proof of extraterrestrial intelligence, to spur deep-space exploration.

I'd love some good science fiction based on that idea at least. Mars seems like a plausible candidate; We ruined it/were forced to leave, fled to Earth, culled the dinosaurs, and made here home.