The single thing which makes any man happiest is the realization that he has worked up to the limits of his ability, his capacity. It's all the better, of course, if this work has made a contribution to knowledge, or toward moving the human race a little farther forward.

It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small.

I put up my thumb and it blotted out the planet Earth.

It never hurts to have friends around, so that's why you'd form a crew.

I believe that the message of Apollo XI was that in the spirit of Apollo, a free and open spirit, you can attack a very difficult goal and achieve it, if you can all agree and work together to achieve that goal.

As I stepped on the moon, I looked around, dazed...magnifice nt. The vast, sandy silver surface was almost illusory.

I fully expected that, by the end of the century, we would have achieved substantially more than we actually did.