If you were alive in July 1969, there's a good chance you remember where you were. Families crowded around television sets, neighbors gathered in living rooms, and people everywhere stayed up late to watch something no one had ever seen: a human being walking on the Moon.
Neil Armstrong's moonwalk was broadcast live to an estimated 600 million viewers, roughly one-fifth of the world's population at the time. That made it among the most-watched television events in history. And the picture they saw took an unusual journey, bouncing from the Moon to giant antennas in Australia before reaching living rooms around the world.
A Night to Remember
Apollo 11 launched from Kennedy Space Center in Florida on July 16, 1969. After three days in transit, Armstrong and Buzz Aldrin landed their lunar module, Eagle, in the Sea of Tranquility on July 20. Michael Collins stayed in orbit aboard the command module, Columbia.
About six hours after landing, Armstrong climbed down the ladder and became the first person to walk on the Moon. Aldrin joined him about 19 minutes later. The live broadcast of the moonwalk went out at 2:56 a.m. Universal Time on July 21, which was late in the evening of July 20 for viewers across the United States. As he stepped onto the surface, he said, "That's one small step for [a] man, one giant leap for mankind."
A Broadcast of a Broadcast
Getting pictures from the Moon was tricky. Apollo 11's camera used a special format called slow-scan television, which regular TV stations couldn't broadcast. So engineers on the ground displayed the signal on a special monitor and pointed a conventional TV camera at it. In other words, the world watched a broadcast of a broadcast, which is part of why the images looked so ghostly.
The signal was picked up at Goldstone in California, but it came in more clearly at the Honeysuckle Creek Tracking Station near Canberra, Australia. Minutes later, the feed switched to the even more sensitive Parkes radio telescope in Australia. Despite technical and weather problems, black-and-white pictures of the moonwalk reached at least 600 million people.
The Missing Tapes
Here's a twist that surprises many people. The original, higher-quality slow-scan recordings straight from the Moon were likely erased. Because the live broadcast had worked and was widely recorded, the backup tapes didn't seem important at the time. In the early 1980s, NASA faced a shortage of data tapes, and the originals were probably wiped and reused.
In the early 2000s, a team of retired NASA employees and contractors searched for years but couldn't find them. Luckily, copies of the broadcast version survived and are widely available.
Two and a Half Hours on the Moon
Armstrong and Aldrin spent about two and a half hours walking on the surface. They planted an American flag, spoke with President Richard Nixon at the White House, set up science experiments, and collected about 47.5 pounds of lunar rock and soil. After more than 21 hours on the Moon, they rejoined Collins, and the crew splashed down safely in the Pacific on July 24.
For the millions who watched, the grainy picture didn't matter one bit. It was a shared moment for a whole planet, and many people can still tell you exactly where they were sitting that night.
