You get to say that the Earth is flat because we live in a country that guarantees your free speech. But it's not a country that guarantees that anything you say is correct.

I would expunge the word "aptitude" from our vocabulary, because if you're interested in something, that's all that matters. You'll spend more time doing it, that than anything else, and possibly more time doing it than anybody else. And that's all that matters, because in the end, if you love what you do, you'll be your best at it compared to anything else you might have chosen as a career.

All Plutophiles are based in America. If you go to other countries, they have much less of an attachment to either the existence or preservation of Pluto as a planet.

When everyone agrees to a single solution and a single plan, there's nothing more efficient in the world than an efficient democracy.

I as an astrophysicist, see the universe, feel the universe, smell the universe every day. Every day. And for people to say, I'm cool, I'm right here, it's all I need.

Just before I said I wanted to be an astronomer I said I wanted to be a baseball player. I was quite athletic at the time, probably because I was bigger than other kids, and if you're bigger than other kids and you're 11 you win everything.

I knew Pluto was popular among elementary schoolkids, but I had no idea they would mobilize into a 'Save Pluto' campaign. I now have a drawer full of hate letters from hundreds of elementary schoolchildren (with supportive cover letters from their science teachers) pleading with me to reverse my stance on Pluto. The file includes a photograph of the entire third grade of a school posing on their front steps and holding up a banner proclaiming, 'Dr. Tyson - Pluto is a Planet!'