"That's one small step for a man...." said Neil Armstrong -- but depending on whom you ask, they may not have been the first words spoken from the moon.
They weren't? Armstrong's crewmate, Buzz Aldrin, sometimes claims that he got in the first line. Six hours earlier, as the Apollo 11 Lunar Module Eagle touched down, it was Aldrin who called out, "Contact light."
Forty years after that historic day, myths and forgotten stories continue to hover over what Armstrong called Tranquility Base. Here, in a similar spirit, are a half dozen things you may never have heard about Apollo 11.
The computer on board Eagle was not much more powerful than a digital watch today, and as the ship descended, its rocket engine at full blast, Armstrong realized the system was steering the astronauts toward a rugged crater the size of a football field.
He took over control, and went shooting over the landscape in search of smoother ground. As he went, Eagle gulped fuel. They ran so low that Aldrin called out, "Contact light," just 17 seconds before mission control would have told the astronauts to jettison the ship's landing stage, fire the ascent engine and abort the landing.
Would Armstrong, knowing by then he was so close, actually have made that risky move? We will never know.
Armstrong's name will live in history. Many people thought at the time he was hand-picked by NASA for the moon landing; he happened to be the only Apollo commander who wasn't a military officer at the time.
But the astronauts' boss, Deke Slayton, had a system of rotating crews among missions. He picked six three-man teams. Each would be the backup crew for one flight, and then actually fly three flights later. Neil Armstrong happened to be the backup commander of Apollo 8, which made him the commander of Apollo 11 – which would not have been the lunar landing flight if Apollo 9 and Apollo 10 had gone badly.
Do you remember Borman's name? He, James Lovell and William Anders flew Apollo 8 around the moon on Christmas Eve, 1968 -- and Slayton thought that experience might make the difference between success and failure for the actual landing. So, breaking with his system, he offered Borman the chance to jump ahead in line and make the lunar landing flight.
Andrew Chaikin, co-author with Victoria Kohl of "Voices from the Moon," interviewed both men, and says Borman turned the offer down.
"He was a team player, a military man, happy to have made a big play, but he didn't feel the need to score the touchdown," said Chaikin. "And his wife was anxious for him to stop flying and risking his life."
So Slayton went back to his regular crew-rotation system, and it is Armstrong's name we are hearing today.
Think of all the vivid color photographs you've seen of the Apollo 11 astronauts on the lunar surface. Almost all the pictures are of Buzz Aldrin, not of Armstrong.
It is one of those nasty little details of history that Neil Armstrong carried the only still camera on the moon walk – so the pictures are by him, not of him. He got Aldrin coming down the ladder to the ground, posing with the American flag, setting up experiments, etc., but Aldrin did not return the favor.
Armstrong did lend Aldrin the camera for a few minutes, during which he mostly shot rocks. Aldrin did shoot one panorama of the landing site, and Armstrong is seen in the corner of one frame. From the rear.
John F. Kennedy was candid about his reasons for the moon race: he wanted to beat the Russians there. By 1969 it was clear the Americans were ahead, but it's been revealed since that up until the last, the Soviets were still trying to win.
Theirs was a high-risk, go-for-broke plan. They built a giant rocket, called the N-1, 345 feet tall, with no fewer than 30 rocket nozzles in its first stage. It was more powerful than the Saturn V that launched the Apollo missions.
The Soviets would have launched two cosmonauts, and only one of them would have landed on the moon. One man, alone, on an entire world.
But the N-1 proved too complex for its own good. It never had a successful test launch, and after Apollo's success, it was abandoned.
Public interest in the moon waned quickly after Apollo 11. But then came Apollo 13 in April 1970, and the oxygen tank explosion that almost killed astronauts Jim Lovell, Jack Swigert and Fred Haise.
Suddenly, the public focused again on space -- in a way that made many in Washington and Houston nervous.
In the end, says author Andrew Chaikin, Apollo 13 proved to be "NASA's finest hour." The 1994 movie, starring Tom Hanks as Lovell, was nominated for a best picture of the year Oscar.
But in 1970, there were a lot of nervous officials in Houston, and in the administration of President Richard Nixon.
"There were people saying to Nixon, 'You're liable to have a disaster on your watch and you shouldn't keep this thing going,'" says Chaikin. In the end, Nixon let the program continue.
"It turns out," says Chaikin, "that Richard Nixon liked heroes."