There's an old saying in the space community: 'If God wanted us to be a spacefaring species, he would have given us a moon'.

The Big Bang Theory: When geeky scientists can be main characters in a hit prime time series, you know there's hope for the world.

New generations of humans inherit the acquired discoveries of generations past, allowing cosmic insight to accumulate without limit. Each discovery of science therefore adds a rung to a ladder of knowledge whose end is not in sight because we are building the ladder as we go along. As far as I can tell, as we assemble and ascend this ladder, we will forever uncover the secrets of the universe - one by one.

I would request that my body in death be buried not cremated, so that the energy content contained within it gets returned to the earth, so that flora and fauna can dine upon it, just as I have dined upon flora and fauna during my lifetime

Robots are important also. If I don my pure-scientist hat, I would say just send robots; I'll stay down here and get the data. But nobody's ever given a parade for a robot. Nobody's ever named a high school after a robot. So when I don my public-educator hat, I have to recognize the elements of exploration that excite people. It's not only the discoveries and the beautiful photos that come down from the heavens; it's the vicarious participation in discovery itself.

I don't want to make a member of Congress do something that that member of Congress's constituents would not approve of, or would not agree to. So in that regard, I'm kind of the opposite of a lobbyist.

The most successful scientists in the history of the world are those who posed the right questions