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

The cosmic calendar is quite a fertile mode for communicating how small we are over time and space.

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 we have the power to turn another planet into Earth, then we have the power to turn Earth back into Earth.

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.

Artificial selection turned the wolf into the shepherd, and the wild grasses into wheat and corn. In fact, almost every plant and animal that we eat today was bred from a wild, less edible ancestor. If artificial selection can work such profound changes in only ten or fifteen thousand years, what can natural selection do operating over billions of years? The answer is all the beauty and diversity of life.

I [do not know] when the end of science will come. ... What I do know is that our species is dumber than we normally admit to ourselves. This limit of our mental faculties, and not necessarily of science itself, ensures to me that we have only just begun to figure out the universe.