“Boy, that sure is weird music.”
“We’re going to have to find out about that. Nobody will believe us.”
“Yes. It’s a whistling, you know, like an outer-space-type thing.”
In 1969, the Apollo 10 astronauts orbited the moon as a test-run for the Apollo 11 moon landing two months later. While they flew around the far side of the moon—which put them out of radio contact with Earth for roughly an hour—they heard some strange sounds that they could not immediately identify.
The entire transcript of their conversation was initially classified by NASA and only released from NASA’s archives in 2008, but the actual recording of the noise was kept under wraps—until now.
NASA released the audio as part of the Science channel’s series, NASA’s Unexplained Files. (You can hear a snippet of the eerie, wind-like noise at 2:05 in the video below.)
Space makes “sounds” all the time—usually due to charged particles interacting with a planet’s magnetic field. In 1979, NASA’s Voyager spacecraft picked up a noise near Jupiter (video) that sounds a lot like what the Apollo 10 astronauts heard orbiting the moon. The Cassini spacecraft recorded sounds around Saturn as well, in 2002.
The thing is, the moon has neither a magnetic field nor an atmosphere meaning the radio transmissions picked up by the Apollo astronauts couldn’t have come from the moon. So it had to be aliens, right?
Not quite. Two months after Apollo 10 heard the sounds, Michael Collins, the Apollo 11 astronaut who stayed in the moon’s orbit while Neil Armstrong and Buzz Aldrin touched down on its surface, heard them too. In his book Carrying the Fire: An Astronauts Journeys, he writes that NASA radio technicians told him beforehand the sounds were the result of interference between the radio in the Lunar Module and the one in the Command Module.
Still, it must have been harrowing to hear sounds of an unknown origin while far from Earth. “Had I not been warned about it, it would have scared hell out of me,” Collins wrote. “A strange noise in a strange place.”