I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

Nowhere in space will we rest our eyes upon the familiar shapes of trees and plants, or any of the animals that share our world. Whatsoever life we meet will be as strange and alien as the nightmare creatures of the ocean abyss, or of the insect empire whose horrors are normally hidden from us by their microscopic scale.

Mars is the next frontier, what the Wild West was, what America was 500 years ago. It's time to strike out anew....Mars is where the action is for the next thousand years....The characteristic of human nature, and perhaps our simian branch of the family, is curiosity and exploration. When we stop doing that, we won't be humans anymore. I've seen far more in my lifetime than I ever dreamed. Many of our problems on Earth can only be solved by space technology....The next step is in space. It's inevitable.

Moses Kaldor had always loved mountains; they made him feel nearer to the God whose nonexistence he still sometimes resented.

Death focuses the mind on the things that really matter: why are we here, and what should we do?

The future is not to be forecast, but created.

Finding intelligent life would encourage people and also of course the opportunity of learning a tremendous amount, but this is a danger. We might be so overwhelmed with knowledge and information, that we might be depressed or even become suicidal - because what's the point if they're thousands of years ahead of us? Why should we bother? - or become the ultimate couch potatoes.