Edgar Mitchell, the sixth man to walk on the surface of the moon, has again claimed that aliens came to Earth to stop various nuclear wars, keeping peace on Earth.

Mitchell is a veteran of the Apollo 14 mission in 1971. He has regularly spoken about his belief in aliens, saying that top-ranking military sources spotted UFOs during weapons test, according to Mirror Online.

"They wanted to know about our military capabilities," he said, according to Fox News. "My own experience talking to people has made it clear the ETs had been attempting to keep us from going to war and help create peace on Earth."

"Edgar Mitchell is an honourable and truthful man, who I've had the privilege of meeting. But so far as I'm aware, most of his information on this issue comes not from things he's experienced himself, but from things he's been told by others," Nick Pope, a former Ministry of Defence UFO researcher, said when asked by Mirror Online if he believes in Mitchell's claims.

UFO believers say that it's no coincidence that aliens showed up very shortly after humans developed atomic weapons and rocket technology, as this is when they were alerted to the threat we pose to the wider cosmos, the Daily Mail reported.