In a rare flash of humor, she had replied: “Woody, a commander can be wrong, but never uncertain. - Arthur C. Clarke

A single test which proves some piece of theory wrong is more valuable than a hundred tests showing that idea might be true.

I've been saying for a long time that I'm hoping to find intelligent life in Washington ... I'm reasonably sure there must be life in this solar system, on Mars or on Europa, and other places. I think life is probably going to be ubiquitous, though we still don't have any proof of that yet — and still less, any proof of intelligent life anywhere. But I hope that will be coming in the next decade or so through radio astronomy or, perhaps, the discovery of objects in space which are obviously artificial. Astronomical engineering — that may be the other thing to look for.

We cannot predict the new forces, powers, and discoveries that will be disclosed to us when we reach the other planets and set up new laboratories in space. They are as much beyond our vision today as fire or electricity would be beyond the imagination of a fish.