Unlike the dinosaurs, we have, in effect, become active agents in changing our destiny. A giant meteor wiped out much of life on earth 65 million years ago because the dinosaurs didn't collectively create a missile shield to deflect the meteor. Humans, on the other hand, with our orbiting telescopes and space probes, and our growing awareness of the threat from space, can track large foreign objects coming from millions of miles away, and are talking about collectively deflecting those that could do us harm.

Mars has become a very busy place, being orbited by satellites and crisscrossed by Land Rovers. As if that's not enough, Curiosity, a roving science laboratory, just successful landed at the planet's ancient crater to probe for signs that the planet was life-friendly in the past. Indeed, we are mapping and processing our neighboring planet so extensively that it feels as if Mars has already been colonized.