Are we all alone? Mars, we are now told, was once teeming with rivers and lakes, so it could have sustained life. Though it was so long ago we would never know.
More than that, there are all sorts of planets in the universe, some of which surely have similar capacity for life. Though so far away that we would never know.
Why this push to deny the uniqueness of Earth? Could it be that evolution becomes less credible if life exists on only one planet in the vast universe? Would we have to accept a biblical creator instead?
— Thomas F. Harkins Jr.,