Before we go there and set up greenhouses, dance clubs, and falafel stands, let's make sure that, in some subtle form that could be harmed by the human hubbub, life does not already exist there. If not, then by all means build cities, plant forests and fill lakes and streams with trout -- bring life to Mars and Mars to life. We'll then be the Martians we've been dreaming about for all these years.
David Grinspoon