It'd be a shame to talk about the universe and not show some images of it, because we have some of the more stunning representations of our field relative to any of the sciences. But I don't use the imagery as a substitute for the insights and wisdom I can convey so that when you leave you say to yourself, "Wow, I'm a little more deeply connected to the universe, and I want to learn more."

I can't think that leaving Earth once is enough.

We in astrophysics we think of the universe all the time. So to us, Earth is just another planet. From a distance, it's a speck. And I'm convinced that if everyone had a cosmic perspective you wouldn't have legions of armies waging war on other people because someone would say, "Stop, look at the universe."

I try to write in a way where you care deeply what the next paragraph will be. I hear the rhythm of prose and that, to me, distinguishes great writing from ordinary writing. By the way, I don't even claim that I'm good. I claim that I value it.

Science is not a subject you took in school. It's life. We are wrapped by it, in it, with it.

People say, oh we just need charismatic leaders to continue on to Mars. Now we've gone to the moon, of course Mars is next. No. Mars was never, of course, next. It is next if you think we went to the moon because we're explorers, but if you know we went to the moon because we were at war then we're never going to Mars. There's no military reason to do it, to justify the expenditure.

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.