When I was a kid, I thought that if everyone looked up the way I did then everyone would want to study the universe just like me - how could they not? This naiveté is what tells me that my interest was more a calling than a rational comparative assessment about what to be when I grew up.

No one wants to die, and no one wants to die poor. These are the two fundamental truths that transcend culture, they transcend politics, they transcend economic cycles.

Asteroids have us in our sight. The dinosaurs didn't have a space program, so they're not here to talk about this problem. We are, and we have the power to do something about it. I don't want to be the embarrassment of the galaxy, to have had the power to deflect an asteroid, and then not, and end up going extinct.

What I’m saying is, when different experiments give you the same result, it is no longer subject to your opinion. That’s the good thing about science: It’s true whether or not you believe in it. That’s why it works.

Apart from the obvious advantages of having ice to melt, filter, then drink, you can also break apart the water's hydrogen from its oxygen. Use the hydrogen and some of the oxygen as active ingredients in rocket fuel and keep the rest of the oxygen for breathing. And in your spare time between space missions, you can always go ice skating on the frozen lake created with the extracted water.

Math is the language of the universe. So the more equations you know, the more you can converse with the cosmos.

The caricature of science is that we hold tight to the theories we have, and shun challenges to them. That's just not true. In fact, we hold our highest rewards for those scientists who can prove others wrong. And by the way, they are famous in their own lifetimes. We don't wait until they're dead.