Science literacy is less about what you know and more about how your brain is wired for asking questions.

Mars once was wet and fertile. It's now bone dry. Something bad happened on Mars. I want to know what happened on Mars so that we may prevent it from happening here on Earth.

Every day, I wake up and I say, 'Why... how... did I end up with 1.7 million Twitter followers?' It's freaky to me, every day, but that tells me that there's an appetite out there that had previously been underserved. There's an inner geek in us all, an inner bit of curiosity that people are discovering, and they like it.

If you're going to lead a space frontier, it has to be government; it'll never be private enterprise. Because the space frontier is dangerous, and it's expensive, and it has unquantified risks. And under those conditions, you cannot establish a capital-market evaluation of that enterprise. You can't get investors.

Space only becomes ordinary when the frontier is no longer being breached.

I was born the same week NASA was founded, so we're the same age and feel some of the same pains, joys, and frustrations.