I have a personal philosophy in life: If somebody else can do something that I'm doing, they should do it. And what I want to do is find things that would represent a unique contribution to the world-the contribution that only I, and my portfolio of talents, can make happen. Those are my priorities in life.

With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.

When students cheat on exams, it's because our school system values grades more than students value learning.

Science reveals that all life on Earth is one.

A successful day for me is when I teach people something. They become enlightened by an idea and learn how to think about it, so that later on when someone says, "Tell me about x, y, z," they don't have to say, "I know this because Tyson told me." No, they'll say, "Here's why it's true because I know and understand it."

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 the purpose of the universe was to create humans then the cosmos was embarrassingly inefficient about it.