Three and a half million years ago our ancestors - yours and mine - left these traces [indicates footprints]. We stood up and parted ways from them. Once we were standing on two feet, our eyes were no longer fixated on the ground. Now, we were free to look up and wonder.

Once you've got the makings of a star, gravity draws leftover gas and dust into a giant swirling disk. The dust continues to stick together, clumping into rocky asteroids, which eventually become orbiting rocky planets. And voila: a solar system!

Science literacy is the artery through which the solutions of tomorrow's problems flow.

You will never find scientists leading armies into battle. You just won’t. Especially not astrophysicists -we see the biggest picture there is. We understand how small we are in the cosmos. We understand how fragile and temporary our existence is here on Earth. We understand there are bigger problems we need to solve as a species than what God you pray to.

If aliens did visit us, I'd be embarrassed to tell them we still dig fossil fuels from the ground as a source of energy.

Some of the greatest poetry is revealing to the reader the beauty in something that was so simple you had taken it for granted.

As important as the civil rights movement was, I think what will rise to the top is that we left Earth in that time.