The dinosaurs never saw that asteroid coming. What's our excuse?

My interest in the space program has a certain purity to it because I recognize the romance of it but I was never seduced by it. That allowed me to view it through a more purely scientific lens. My interest in space while in school came about through my scientific activities.

The most successful people recognize that in life they create their own love, they manufacture their own meaning, they generate their own motivation.

After your first job, is anyone asking you what your GPA was? No, they don't care. They ask you: Are you a good leader? Do people follow you? Do you have integrity? Are you innovative? Do you solve problems? Somebody's got to do that homework and redesign the educational system so that it can actually train people to be successful in life.

If Mars formed life, then life on Earth could have been seeded by life on Mars, making every life form on Earth descended from Martians.

85 percent of the gravity of the universe has a point of origin about which we know nothing.

If our solar system is not unusual, then there are so many planets in the universe that, for example, they outnumber the sum of all sounds and words ever uttered by every human who has ever lived. To declare that Earth must be the only planet with life in the universe would be inexcusably bigheaded of us.