Even with all our technology and the inventions that make modern life so much easier than it once was, it takes just one big natural disaster to wipe all that away and remind us that, here on Earth, we're still at the mercy of nature.

This fear factor, this war driver is a very strong one and it's been with the species ever since the beginning and it motivated the Great Wall of China. War can be aggressive or defensive, right? So it motivated the Great Wall of China. Our space program was reactive to Russia.

Hunting for meteorites is like trying to find a pebble on miles of beach.

I'd go back and hang out with Isaac Newton. I'm torn between do I hang out with him or do I bring him into the present to hang out with me. See, that might be terrifying because his head will just explode once he sees everything that was derived from his discoveries, but I'd spend more time with someone who I think is one of the most brilliant minds our species has ever known.

It's progress I think, that science has joined philosophy, metaphysics & religion as subjects drunk people argue about in bars.

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

Science is not there for you to cherry pick ... You can decide whether or not to believe in it but that doesn’t change the reality of an emergent scientific truth.