IT'S the weird and wonderful place where the men in grey suits from Whitehall meet the little green men from Mars.
Do you have any photographs of UFOs? Share them with us by emailing them to email@example.comThe Ministry of Defence has for the first time opened its real-life 'X Files', detailing how its experts have examined photographs of UFOs hovering over the UK.
While the images range from the baffling to the risible, there is no doubting the seriousness that officials reserve for the issue of extraterrestrial life.
Correspondence between the MoD and members of the public who report sightings of strange objects reveals that Whitehall mandarins remain "totally open-minded" about the existence of UFOs.
The letters - obtained by Scotland on Sunday through the Freedom of Information Act - confirm that the MoD has a procedure of scrambling fighter planes to confront any unidentified craft or object that enters UK airspace.
However, there are hints that at least some strange objects seen in the sky are of a distinctly terrestrial provenance.
In one letter, officials admit that military helicopters carry out low-flying combat training missions across Britain, and apologise for any alarm they may have caused.
The MoD has confirmed it receives more than 100 reports of UFO sightings every year, many of which come from Scotland.
Last year alone, the Ministry was sent five sets of photographs and videos purporting to show UFO activity.
One was sent by a concerned resident who last March reported seeing silent superfast "triangular craft" and other strange objects in the skies above the south of England.
He enclosed a picture that appears to show a ball of light moving at speed across the sky with an illuminated trail in its wake.
A lengthy official response from the MoD's Directorate of Air Staff is at pains to reassure the individual.
It states: "We remain totally open-minded, but to date we know of no evidence which substantiates the existence of these alleged phenomena.
"The MoD examines any reports of unidentified flying objects it receives, solely to establish whether what was seen might have some defence significance; namely whether there is any evidence that the UK's airspace might have been compromised by hostile or unauthorised air activity."
The letter claims the Ministry could not justify spending public money on being an "aerial identification service", but stresses that every precaution is taken to protect the integrity of UK airspace.
It adds: "I should inform you that low-flying training takes place throughout the UK.
"In the event of conflict, helicopters are vulnerable to ground fire, and one of the vital skills that must be acquired by pilots is flying as closely as possible to the nap of the earth so that the aircraft is shielded and camouflaged by the features of the terrain.
"This type of training is spread as thinly as possible throughout the UK, so as not to concentrate activity over one area. I am sorry if this training has caused disturbance to you."
The MoD also received a succession of images of objects in the sky above Portsmouth harbour last July.
And in one decidedly eccentric letter last May, a concerned citizen warns the MoD that she and her husband are being menaced by invisible craft, the grey alien inhabitants of which have already abducted her in the past to "extract her DNA".
To support her case, she enclosed a photograph of an all-too-visible object (possibly a Frisbee or a satellite dish) "hovering" over a church.
In an impeccably polite response, MoD officials come to the sober conclusion that: "With regard to your particular observations, we are satisfied that there is no corroborating evidence to suggest that the UK's airspace has been breached by unauthorised aircraft."
In another response to an individual who claimed to have provided film evidence of UFO activity over the Clyde in Glasgow last year, an official states frankly: "I have viewed your video and I am content that it contains nothing of defence concern."
The MoD confirmed that in 2006 it received more than 100 reports of UFO sightings, including 12 from Scotland.
The previous year around 150 sightings were reported, with again a dozen coming from north of the Border. These included six reported sightings on the same day (September 14, 2005) in Fife and Perthshire of "bright white lights" in the sky.
The unidentified objects were sighted in Lochgelly, Glenrothes, Crieff, Letham, Blairgowrie and Kinross.
Nick Pope, who headed the MoD's UFO Project between 1991 and 1994, confirmed that reported sightings were taken extremely seriously.
"The MoD wants to know everything flying in the UK's air-defence range and investigate all sightings," he said.
Pope revealed that 95% of UFO reports turned out to either have obvious explanations or to be so vague that any investigation was impossible.
"The remaining 5% of cases were pretty interesting and remained unexplained even after a very thorough explanation. It doesn't prove that these objects were extraterrestrial, but you can't rule any option out."
The former MoD investigator even claimed that officials tried to copy the advanced technology of unidentified vehicles.
"A number of reports were of silent triangular aircraft travelling at considerable speed," he said. "These and some other reports suggested some sort of propulsion system we would be extremely interested in.
"A lot of the serious UFO investigation was aimed at trying to ascertain things such as the aerodynamics of some of the UFOs, the avionics and the propulsion systems.
"We wanted to know if there was anything that we might learn from, regardless of what the source of these UFOs is."
Have you seen UFOs flying above Scotland or do you think the whole idea of little green men is pie in the sky? Tell us what you think and discuss extra-terrestrial matters with other readers.