I've said multiple times that the world's first trillionaire is going to be the person who exploits the resources of asteroids, the natural resources that are rare on earth and common on selected asteroids. So there are many different reasons you might want to go into space. You might want to spend your honeymoon on the far side of the moon.

As they are currently practiced, there is no common ground between science and religion... Although just as in hostage negotiations, it's probably best to keep both sides talking to each other.

Three and a half million years ago our ancestors - yours and mine - left these traces [indicates footprints]. We stood up and parted ways from them. Once we were standing on two feet, our eyes were no longer fixated on the ground. Now, we were free to look up and wonder.

I am convinced that the act of thinking logically cannot possibly be natural to the human mind. If it were, then mathematics would be everybody's easiest course at school and our species would not have taken several millennia to figure out the scientific method.

There's no shortage of people that we can put on, because science touches us all.

The number of people in the world engaged in this search for catastrophic impactors totals one or two dozen. How long into the future are you willing to protect Homo sapiens on Earth? Before you answer that question, take a detour to Arizona's Meteor Crater during your next vacation.

No one is dumb who is curious.