When you innovate no one else can figure out how to do what you're doing because you're too far ahead of them. And the day they do figure out, you're on to the next object, the next widget, the next concept in innovation. And so America has benefited economically from the space race even though it was driven by military.

I try to educate the public and let them make the decisions for themselves.

If you love what you do, you'll be your best at it compared to anything else you might have chosen as a career. Or at least you will love it more, and you won't lead a depressed day of your life.

The universe's destiny has very little to do with the near-term destiny of Earth.

The chances that your tombstone will read 'Killed by Asteroid' are about the same as they'd be for 'Killed in Airplane Crash.'

Everything we do understand about the universe - the periodic table of elements, Einstein's laws, Newton's laws, all of chemistry, all of biology - that's 4 percent of the universe. We got to the moon on the 4 percent we do understand. We landed on Mars on the 4 percent we do understand. So the day we crack the nut of the rest of that 95 percent... Oh my gosh.

Italy valued cathedrals while Spain valued explorers. So worldwide, five times as many people speak Spanish than Italian.