The memo was sent at the height of the Cold War and considered if the number of UFO sightings could be predicted or controlled or, more sinisterly, even “used from a psychological warfare point of view, either offensively or defensively”.
It said studies showed public concern, not just in the US but wider, with the phenomena, was so strong that many people may be pre-conditioned to accept the incredible as being true.
The memo added that news of potential alien activity had the potential to spark mass hysteria and panic.
Since 1947, the Air technical Intelligence Centre, had received 1,500 official sighting reports, plus more from the public and press.
In July 1952 there were 250 reports, and of all sightings 20 per cent remained unexplainable.
“A study should be instituted to determine what, if any, utilisation could be made of these phenomena by United States psychological warfare planners.”
The paranoia of the Cold War was evident in the memo, which spoke of fears of a Soviet plot to use fear of UFOs against the US public.
The memo added it would need to establish “what, if any, defences should be planned in anticipation of Soviet plans to utilise them”.
Mr Chadwell continued: ”Other intelligence problems which require determination are: possible Soviet intentions and capabilities to utilise these phenomena to the detriment of United States security interests.”
It is not clear from the releases what further work was done in these areas, but there are not thought to be any cases on record of either the US or Soviet Union using UFO fears in any form of attack, defence or psychological warfare.
However, the disclosure will likely fuel ongoing conspiracy theories which claim the US military and intelligence services maintain a strong interest in the phenomena.
It was a US military scientific project which has spawned even more conspiracies than the Large Hadron Collider.
It was established by the US Air Force to study the Earth’s ionosphere – a highly charged and active part of the upper atmosphere.
But many conspiracists always claimed it was a cover for secretive tests to control the weather or even to research “captured UFO technology” or create a false flag hologram.
The air force ended the project in 2014, but some claim it continues.
UFO buffs maintain a strong interest in the mysterious top-secret Area 51 military base in the Nevada desert, where it is claimed all evidence of alien visitation of Earth is kept and engineers use recovered alien technology to boost their own.
The CIA has previously said it no longer has an interest in the UDFO phenomena, as no real national security threat was ever identified.