I want to reach a new generation. That's why I am Twittering now. I have a BlackBerry, an iPhone and a Mac.

The best way to study Mars is with two hands, eyes and ears of a geologist, first at a moon orbiting Mars... and then on the surface.

I was not the commander, I was a junior person, so once both were outside, I followed my leader, because we (NASA) had not put together detailed jobs of people outside. I believe it could have been improved. But it was very successful for what it was.

Certainly, I've never wanted to live on past achievements.

I'm not in favor of just taking short-term isolated situations and depleting our resources to keep our climate just the way it is today.

Timing has always been a key element in my life. I have been blessed to have been in the right place at the right time.

My first inclination is to be a bit skeptical about the claims that human-produced carbon dioxide is the direct contributor to global warming.