If either Mars or Venus had been Earth type planets and had Human life evolve on them then, if those humans had devloped at a similar rate to ourselves then how much of a difference would it have made to our rate of social and technological development and the space program itself, assuming of course that we discover that each planet is inhabited and try to contact them?
Do you think it'd make any difference to allow us to develop at least interstellar flight between planets?
Do you think it'd make any difference to allow us to develop at least interstellar flight between planets?