Cernan: Boy, that sure is weird music.
Young: We’re going to have to find out about that. Nobody will believe us.
-Apollo 10 transcript
This weekend, the Science Channel released the preview for their newest episode of NASA’s Unexplained Files that told the story of Apollo astronauts who heard weird sounds during their trip around the moon.
The “space music” was heard during the Apollo 10 mission when astronauts Thomas P. Stafford, Gene Cernan, and John Young were on the far side of the moon. As a type of “dress rehearsal” for the first moon landing, the Apollo 10 astronauts went through all of the necessary procedures just short of landing on the lunar surface.
During the mission, Stafford and Cernan went into the lunar lander while Young stayed inside the command module. The two spacecraft separated when the crew was on the far side of the moon and it was at this point in the mission when the astronauts began to hear a weird noise.
Young: Did you hear that whistling sound, too?
Cernan: Yeah. Sounds like – you know, outer-space-type music.
Young: I wonder what it is.
-Apollo 10 transcript
The “space music” can be heard at the 2:05 mark in the video below.
So what was this mysterious, but mostly just annoying, noise that the astronauts heard?
In his book, Carrying the Fire, Apollo 11 astronaut Michael Collins explained that he had heard a similar noise when he was on the back side of the moon. He said it was certainly “a strange noise in a strange place.”
However, Collins noted that NASA radio technicians had a pretty easy explanation: the sound was caused by radio interference.
The kind of noise the Apollo astronauts heard is common to those who frequently operate radios. It can happen when radio waves interfere with the transmission of other radio waves passing through the same path.
The “space music” radio interference occurred when the crew separated the command module and the lunar lander and each spacecraft turned their radios on.
Despite this somewhat mundane explanation, this story has drawn a lot of attention, mostly because of a few misconceptions about what really happened.
Collins’ book came out in 1974, but NASA didn’t officially release the transcripts until 2008. This lead people to believe (and the Science Channel episode suggests) that the “space music” information may have been covered up by NASA. But today, the NASA History Office was quick to correct that theory.
The full transcripts and audio of the mission are available for anyone who’d like to listen to or read through them.
In addition to questioning NASA’s motive for waiting until 2008 to officially release this information, some have noted that the location where the astronauts heard the noise was peculiar in itself. Many incorrectly referred to the location as the “dark side” of the moon, which makes the entire situation feel much more mysterious.
However, there is no “dark side” of the moon. The lunar dark side myth propagates the belief that there is a frozen, desolate side of the moon which never receives sunlight.
This myth came to be because, here on Earth, we can only see one side of the moon. Tidal locking causes the moon to rotate about its axis at the same rate it takes for it to orbit around our planet.
Because of this, we only see one side of the moon. But this doesn’t mean that the Earth-facing hemisphere receives more sunlight. Both hemispheres experience the same amount of sunlight and darkness.
With that said, hearing a weird noise at a time when your spacecraft was in radio silence with NASA was probably pretty unnerving. Reading through the transcripts, it’s obvious that the astronauts were a little confused. But in the end, it wasn’t aliens or a NASA cover-up, just a little radio interference in an otherwise very, very quiet place.