Thousands of UFO sightings and an "alien abductions" are detailed in the close-encounter documents released by the National Archives today.
To the wannabe Mulder and Scullys out there we should point out that the intelligence papers on a reported UFO sighting known as the "Rendlesham incident" have gone missing.
The missing files relate to a report of mysterious lights from US servicemen at RAF Woodbridge in Suffolk in 1980.
The disappearance came to light with today's release of 8,000 previously classified documents on UFOs.
Officials found a "huge" gap where defence intelligence files relating to the case should be, the papers show.
Photographs and sketches of UFOs made by members of the public are included, as well as their eyewitness reports.
Among the documents is testimony from an airline pilot and his son who say they spent five minutes watching an object made up of three circles fly past their garden in Hellingly, East Sussex.
The pilot reported it to Air Traffic Control in West Drayton, and an official labelled his sighting as one by "a credible witness".
But another defence official later wrote a memo saying the report "contains nothing of air defence significance".
More attention is given to the crew of an RAF Tornado who encountered an object the size of a C130 Hercules transport aircraft while flying over the North Sea in 1990.
The pilot describes flying at Mach 0.8 but being overtaken by an aircraft the like of which he had never seen before.
He talks about lights and even "an engine area" but the files also show how a possible explanation emerges - a Russian rocket booster was re-entering the earth's atmosphere on that same night.
Another file released reveals six small "flying saucers" were found by members of the public in locations across southern England in 1967. Four police forces and the army were mobilised before it emerged the incident was a rag-day hoax by engineering students from Farnborough Technical College.
So if you want to know what kind of little green man secretes the UK government has been keeping from you now is the time to have a look - the files are only available free on the website for a month.