The chances that your tombstone will read 'Killed by Asteroid' are about the same as they'd be for 'Killed in Airplane Crash.'

Odd how often blood is shed to obtain freedom from those in power. Oppressors must be the most insecure people in the world.

I try to educate the public and let them make the decisions for themselves.

Life existed on Earth for nearly four billion years before anything remotely resembling a human being showed up. And even then, when we started to branch off from other apes about 10,000,000 years ago, our ancestors looked pretty different.

The greatest teachers are the ones that turn a B student into an A student, or a failing student into a B student.

The show [ StarTalk ] was born as a radio program out of a National Science Foundation grant.

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.