Climate has been changing for billions of years.

Unless we are able to commit to a permanent growing settlement [on Mars], then I don't think just going there with humans and coming back is worth doing. The expense of planning to come back is like the people who left Europe to come to America and then to turn around and go back to Europe, it really doesn't make any sense at all.

It was designed to have an impact on the stalemate over Mutually Assured Destruction with the Soviet Union. Us reaching the moon convinced Gorbachev and other leaders that the Soviet Union couldn't compete with the U.S., so they revised their agenda. But people have short memories.

The moon I see now is the same moon I saw before. Except that before, when I looked at it, it was in anticipation of what it would be like when I got there. That's behind me now.

I was lucky enough to have been born on this planet earth, in this admirable country of the United States of America.

The way I see it, what is going to come out of the moon activities is a respect for U.S. leadership.

Walking around on the moon was significantly easier than we'd thought it would be. There weren't any balance problems, so you weren't tumbling over.