I have thoughts every day that are themselves tweets.

Would a NASA reality show "Lunar Shore" be more popular than "Jersey Shore?" Civilization's future depends on that answer.

Some molecules - ammonia, carbon dioxide, water - show up everywhere in the universe, whether life is present or not. But others pop up especially in the presence of life itself. Among the biomarkers in Earth's atmosphere are ozone-destroying chlorofluorocarbons from aerosol sprays, vapor from mineral solvents, escaped coolants from refrigerators and air conditioners, and smog from the burning of fossil fuels. No other way to read that list: sure signs of the absence of intelligence.

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.

(Space programs are) a force operating on educational pipelines that stimulate the formation of scientists, technologists, engineers and mathematicians... They're the ones that make tomorrow come. The foundations of economies... issue forth from investments we make in science and technology.

By the way, how much does NASA cost? It's half a penny on a dollar. Did you know that? ... The most powerful agency on the dreams of a nation is currently underfunded to do what it needs to be doing, and that's making dreams come true ... How much would you pay for the universe?

I look up at the night sky, and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than both of those facts is that the Universe is in us. When I reflect on that fact, I look up — many people feel small, because they’re small and the Universe is big, but I feel big, because my atoms came from those stars.