If you don't question you're stuck within a pre-existing parameters of knowledge. Questions are what take you outside of those parameters.

Facts are true whether or not you believe them.

No one is dumb who is curious.

Something we all have as kids and is beaten out of us as adults. Parents come up to me, "How do I get my kids interested in science?" They're already interested in science. Just stop beating it out of them.

When NASA dreams big America dreams big. People...kids say, 'I want to do that when I grow up'. Because you want to do what's visible to you.

If it's a new planet, sign me up. I'm tired of driving around the block, boldly going where hundreds have gone before in orbit around earth-give me a place to go and I'll go.

I'm often asked whether I believe in Global Warming. I now just reply with the question: "Do you believe in Gravity?"