Science is like an inoculation against charlatans who would have you believe whatever it is they tell you.

Science literacy is a vaccine against the charlatans of the world that would exploit your ignorance.

I think we are all the sum of that which has happened in our lives. And if you're successful, it would be wrong to think that you'd be more successful had something been easier. That's not a given.

The value of the space program is beyond science, it's beyond military; it's a cultural shift in how we think of our place in the universe.

On Friday the 13th, April 2029, an asteroid large enough to fill the Rose Bowl as though it were an egg cup will fly so close to Earth that it will dip below the altitude of our communication satellites. We did not name this asteroid Bambi. Instead, we named it Apophis, after the Egyptian god of darkness and death.

If we have the power to turn another planet into Earth, then we have the power to turn Earth back into Earth.

In whatever you choose to do, do it because it's hard, not because it's easy. Math and physics and astrophysics are hard. For every hard thing you accomplish, fewer other people are out there doing the same thing as you. That's what doing something hard means. And in the limit of this, everyone beats a path to your door because you're the only one around who understands the impossible concept or who solves the unsolvable problem.