Thought outer space is just an eerily quiet, empty space? You better think again.
Astronauts who joined the Apollo 10 space mission in May 1969—which paved the way for the first ever spaceflight that landed humans on the moon just two months later—revealed that they heard mysterious "outer space-type music" while in orbit on the far side of the Moon in May 1969.
This mystery will be tackled in an upcoming episode of the Science Channel series entitled "NASA's Unexplained Files."
According to a report by Fox News, the astronauts heard the strange sound once their spacecraft entered lunar orbit and got within 5,000 feet of the moon's surface, the closest distance mankind ever came close to the Earth's satellite before Apollo 11's historic moon landing.
Recordings of conversations between the three Apollo 10 astronauts – Tom Stafford, John Young and Eugene Cernan – captured the moment when they heard the bizarre space sound.
"It sounds like, you know, outer space-type music," one of the astronauts was heard saying.
They then discussed whether they should inform the National Aeronautics and Space Administration (NASA) about what they heard.
"Shall we tell [NASA] about it?" an astronaut asked.
"I don't know," his colleague replied. "We ought to think about it."
This conversation took place while the three astronauts were on the far side of the moon, out of radio communication with Earth.
There was no record of the astronauts reporting the strange noise to the space agency, or them talking about the incident in public. Their conversation was only unearthed in 2008.
Some believe the noise the astronauts heard came from interference from VHF radios on the command module and lunar module interacting with each other.
Apollo 15 Command Module Pilot Al Worden, however, believes that the mysterious sound came from something else.
"The Apollo 10 crew is very used to the kind of noise that they should be hearing. Logic tells me that if there was something recorded on there, then there was something there," Worden explained.
