In the words Neil Armstrong chiselled into history, it was one small step for a man.
But were the Moon landings really mankind's greatest scientific leap or the most fantastic hoax ever pulled?
The thrilling TV pictures, so faint and grey that we might have been peering at a ghost moving through a thick fog, certainly showed a bulky shape in a spacesuit backing down a ladder, stretching out a leg, tentatively putting one booted foot on to the surface.
The surface of where, though? The Moon or an elaborate mock-up in a movie studio somewhere in a remote corner of an Earthly desert? More...