distance to Earth? Given that the universe is expanding & everything is getting further away from each other;; how long ago would it have been when our nearest stellar neighbours (with Earthlike planets) have been close enough to our own solar system, to be within travelling distance? (Assuming there was someone around, advanced enough to make the trip.) Now, If you have made a reasonable guess or estimate at this, Compare your estimate with the estimated time of the appearance of Life on Earth. ..... What did you come up with?