We didn't go to the moon to explore or because it was in our DNA or because we're Americans. We went because we were at war and we felt a threat.

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!'

We only went to the moon for military reasons. The space enthusiasts of the day kept saying, "Oh, we're on the moon; we should be on Mars in ten years." That's if it was driven by exploration, but it's never been driven by exploration.

If each dead person became a ghost, there'd be more than 100 billion of them haunting us all. Creepy, but cool.

Last I checked, Bill Gates was worth $50 billion. If the average employed adult, who is walking in a hurry, will pick up a quarter from the sidewalk, but not a dime, then the corresponding amount of money given their relative wealth that Bill Gates would ignore if he saw it lying on the street is $25,000.

Too many people view on [space exploration] as a luxury rather than as a fundamental driver to stimulate interest in science to everyone in the educational pipeline. It's vital to our prosperity and security.

There's a lot of memorization that goes on in school. You memorize vocabulary words and all these sorts of things.