While we may lose track of certain goals intermittently throughout the decades, I think we as a nation can be nimble when we need to be. All the buzz today is on the need for science literacy. That is on the agenda in ways it hasn't been in previous decades.

The Earth is just one place of many that we could hang our hats.

With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.

My goal is not to shove information into your head. It's to find ways to reignite the curiosity that we all had as children for the natural world. You don't have to tell a child to explore the backyard.

UV is bad for molecules because its high energy breaks the bonds between a molecule's constituent atoms. That's why UV is bad for you, too: it's always best to avoid things that decompose the molecules of your flesh.

I don't ever tell people what to do! Even if it seems and feels that way sometimes, I don't think I should tell a person how to spend their money. I try not to tell people what to read.

When you're a hammer (as the saying goes), all your problems look like nails. If you're a meteorite expert pondering the sudden extinction of boatloads of species, you'll want to say an impact did it. If you're an igneous petrologist, volcanoes did it. If you're into spaceborne bioclouds, an interstellar virus did it. If you're a hypernova expert, gamma rays did it.