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 Mars or on Europa, and other places. I think life is probably going to be ubiquitous, though we still don't have any proof of that yet — and still less, any proof of intelligent life anywhere. But I hope that will be coming in the next decade or so through radio astronomy or, perhaps, the discovery of objects in space which are obviously artificial. Astronomical engineering — that may be the other thing to look for.

"Meeting of the Minds : Buzz Aldrin Visits Arthur C. Clarke" by Andrew Chaikin (27 February 2001)

Meeting of the Minds: Buzz Aldrin Visits Arthur C. Clarke