Despite hundreds of films, science fiction and fantasy novels as well as thousands of conspiracy theories, humans have never found proof of aliens existing or ever contacting Earthlings.

In fact, Area 51, one of the most secretive military bases in the United States, is actively believed by thousands of people to be the site of alien experiments conducted by the Central Intelligence Agency (CIA). However, CIA employee turned whistle blower Edward Snowden recently debunked one of the biggest conspiracy theories prevalent in the US - that aliens managed to contact the US government and/or its security agencies and that the government actively hides this bit of information from the world.

In his recently released memoir "Permanent Records", however, Snowden revealed that during his time at the CIA, he had searched the CIA databases and resources find out if the US or any of its agencies had ever been in contact with extraterrestrial creatures. However, Snowden found no evidence of any official (or unofficial) contact with aliens. "For the record, as far as I could tell, aliens have never contacted Earth, or at least they haven't contacted US intelligence," Snowden writes in his recent memoir," Snowden wrote.

He also confirmed that the moon landing, another famously disbelieved moon landing - a favourite with conspiracy theorists in US - did indeed happen.

"In case you were wondering: Yes, man really did land on the moon. Climate change is real. Chemtrails are not a thing," he wrote.

Snowden repeated the same on a recently aired podcast episode on an episode of “The Joe Rogan Experience” podcast where he said, "I had ridiculous access to the networks of the NSA (National Security Agency), the CIA, the military, all these groups. I couldn't find anything".

However, he did not completely dismiss the idea of aliens existing. "If we are hiding them (aliens)...it's hidden really damn well, even from people who are on the inside".

Theories of alien invasion, alien abductions, weird experiments and UFO sightings have been part of American pop culture for over a century. The "Black Knight" satellite theory, for example, states that an alien satellite that exists in Earth's orbit and could some day attack Earth.

However, it looks like Snowden just rained on the conspiracy parade.