Earth Day was established in 1970, and that was no accident. We were just beginning to see the Earth in a new way — from space. It is one thing to know intellectually that we live on a ball of dirt floating in the middle of infinite nothingness — it was quite another thing to see it as we saw it in those first photographs from the moon landings. Suddenly it was all too clear that this was it — this was all we had or would ever have by way of real estate, and perhaps we should take care of it.