The danger of asteroid or comet impact is one of the best reasons for getting into space : I'm very fond of quoting my friend Larry Niven: 'The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!'

We should be less concerned about adding years to life, and more about adding life to years. I have been very fortunate to have witnessed some of humanity's gr…

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 Mar…

The intelligent minority of this world will mark 1 January 2001 as the real beginning of the 21st century and the Third Millennium.

I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single p…

I think it would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on th…

All civilizations become either spacefaring or extinct.