As important as the civil rights movement was, I think what will rise to the top is that we left Earth in that time.

The last person I ever want working for me is someone who says 'that's not in my job description.

My interest in the space program has a certain purity to it because I recognize the romance of it but I was never seduced by it. That allowed me to view it through a more purely scientific lens. My interest in space while in school came about through my scientific activities.

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.

In five billion years, the sun will expand and engulf our orbit as the charred ember that was once Earth vaporizes. Have a nice day

I as an astrophysicist, see the universe, feel the universe, smell the universe every day. Every day. And for people to say, I'm cool, I'm right here, it's all I need.

The history of exploration has never been driven by exploration. But Columbus himself was a discoverer. So was Magellan. But the people who wrote checks were not. They had other motivations. And there's Columbus - he couldn't even get Italy to pay for his voyage so he has to go to Spain.