While Apollo 11 astronaut Neil Armstrong and Buzz Aldrin made "one giant leap for mankind" on the moon's dusty surface, command module pilot Michael Collins continued to circle the moon.

On each 48-minute circuit Collins would, for a time, be totally blocked from Earth by the moon -- billions of people on one side, just himself and the great unknown on the other. But, far from feeling isolated or frightened in the darkness, Collins says in In the Shadow of the Moon, his emotion was something grander: "Exultation."

The 2007 documentary is a glimpse into the memories of the men who walked on the moon, the countless people who worked behind the scenes and the billions around the world who breathlessly watched the first, flickering black-and-white images.

I'm in my 40s, and can vaguely remember these Apollo missions, massive flames billowing as the rockets strained into the air, red-and-white-striped parachutes slowing the space capsules as they hurtled back to Earth. But those missions were eons ago. Charlie Duke of the Apollo 16 mission says, "My father was born shortly after the Wright brothers. He could barely believe that I went to the moon. But my son, Tom, was 5. And he didn't think it was any big deal."

By now, it's been so long since anyone's stood on the moon that, for most people on Earth today, the moon landings are ancient history.

So these few men, many of them pushing 80, are the last link to an era when, as Jim Lovell says, it "was a time when we made bold moves." They speak of their lunar craft as if that machinery were another human crew member; they get misty talking about the emotions that rise looking at the jewel of Earth's circle suspended in blackness; Eugene Cernan admits to guilt that astronauts were considered heroes before they ever flew into space while, meanwhile, many of their pilot colleagues were fighting, getting captured and dying in Vietnam.

As In the Shadow gains momentum, it goes beyond the usual talking-head documentary style, or the re-enactment of Apollo 13 with astonishing rare or never-seen footage of the flights, of the speech President Nixon recorded in case Apollo 11 ended in disaster, and of people around the world in 1969 anxiously awaiting Apollo 11 reports and erupting in joyous celebration when the astronauts landed safely.

"We were greeted worldwide with people cheering 'We did it!' " Collins says. "I thought that was wonderful -- ephemeral, but wonderful."

And you're left to wonder: Will any triumphant event ever unite the world in quite the same way again?