During the Apollo 10 mission, which was the mission before the infamous moon landing, NASA astronauts recall hearing strange music in their headsets during their moon flyby.

Just months before Apollo 11's history-changing mission, Apollo 10 astronauts Thomas Stafford, John Young and Eugene Cernan recorded strange "outer-spacey sounding" music when they were on the far side of the moon. Those strange sounds and the conversation that followed was transmitted to NASA's Mission Control Center in Houston, TX.

Those conversations remained under wraps for over 40 years. The story of the strange discovery during Apollo 10, will be talked about on NASA's Unexplained Files on the Science Channel. You can watch snippets of the show segment in the videos above and below.