If Mars formed life, then life on Earth could have been seeded by life on Mars, making every life form on Earth descended from Martians.

Where did the concept of "without borders" come from? No one had that concept until you saw Earth from space, illustrated not by a mapmaker who's color-coding political boundaries; it's illustrated by nature itself and there's land, there's ocean, there's atmosphere.

You ask people, do you pray to [a person or] God. If you say yes to that, you're religious by, presumably, anybody's standards of your conduct. And it's the yes to that question that applies to 40% of scientists. So, there're plenty of atheists who are scientists or not scientists. There maybe a conflict but many people in this country coexist in both worlds.

Let us not fool ourselves into thinking we went to the Moon because we are pioneers, or discoverers, or adventurers. We went to the Moon because it was the militaristically expedient thing to do.

I agree that we should go back to the moon and on to Mars. We should treat all objects in the solar system, including comets and asteroids, as exploration targets.

There is a theorem that colloquially translates, You cannot comb the hair on a bowling ball. ... Clearly, none of these mathematicians had Afros, because to comb an Afro is to pick it straight away from the scalp. If bowling balls had Afros, then yes, they could be combed without violation of mathematical theorems.

As a scientist, I want to go to Mars and back to asteroids and the Moon because I'm a scientist. But I can tell you, I'm not so naive a scientist to think that the nation might not have geopolitical reasons for going into space.