The recording is between astronaut John Glenn and mission control on Earth as he orbited Earth in a space capsule on February 20 1962 as the first US astronaut to do it for an extended period.
In the audio Mr Glenn, who calls himself Friendship Seven, can heard describing seeing a “brilliant blue horizon” coming up behind him as it approaches sunrise.
Then, he suddenly realises something peculiar is happening as several UFOs appear.
He said: “This is Friendship Seven. I’ll try to describe what I’m in here.
“I am in a big mass of some very small particles that are brilliantly lit up like they’re luminescent.
“I never saw anything like it.
“They’re coming by the capsule and they look like little stars.
“A whole shower of them coming by.”
he said they swirled around the capsule, were brilliantly lit, at seven or eight feet apart and all around the capsule.
He was asked by mission control if he heard any impact with the capsule, to which he said no.
He added: “They’re very slow. They’re not going away from me more than maybe three or four miles per hour.”To read more, click here.