"We have the same laws of chemistry, physics. If there are any locations where there are the basic ingredients, there should be the basic ingredients for life."

NASA

Charles Elachi, Director of the NASA Jet Propulsion Lab at Caltech, doesn't hesitate when he's asked about life beyond earth. "Personally, I think absolutely," he said today at The Atlantic's Big Science Summit in San Jose, California. "We have the same laws of chemistry, physics. If there are any locations where there are the basic ingredients, there should be the basic ingredients for life."

One ingredient, of course, is water. On Mars, images from orbit show what looks like dried up drainage channels. Elachi compares them to the patterns you can see as you fly over Egypt's desert -- an imprint that marks where water once was. The Mars rovers Spirit and Opportunity found other hints of water on Mars as well. "We found rocks that have been modified by the presence of water," he said.

It would be ideal, of course, if NASA's newest arrival on Mars, the Curiosity rover, were to stumble upon a fossil. But absent that, NASA will continue gathering data, looking for signs of that something might have lived 127 million miles away. Much of the intense interest, says Elachi, spring from the similarities between Earth and Mars. "They have similar initial conditions. One went this way and and the other went that way. How did life start on this planet [Mars] and somehow stop? Or it never started?"