(NEWSER) – Sorry, Pink Floyd, you no longer hold the sole claim to sounds from the dark side. In an upcoming episode of the Science Channel's NASA's Unexplained Files, audio from Apollo 10—which flew to the far side of the moon in 1969, two months before Apollo 11's moon landing—reveals conversations among the astronauts as they hear odd sounds from the cosmos through their instruments, CNN reports.
"Did you hear that whistling sound, too?" one asks. "Sounds like … you know, outer-space type music," another answers. "I wonder what it is." Whatever "it" was, astronauts Eugene Cernan, John Young, and Tom Stafford were wary of informing their higher-ups what they were hearing while out of contact with Earth. "Shall we tell [NASA] about it?" one asks, per Fox News. "I don't know," says another. "We ought to think about it." They opted for silence, thinking such a report might "cast doubt on their suitability for future spaceflight," per CNN.