In a 1995 briefing now published by the National Archives, a desk officer said the purpose of reported alien craft sightings needs to be established as a matter of priority, adding there did not appear to be hostile intent.
If the sightings are of devices not of the earth then their purpose needs to be established as a matter of priority. There has been no apparent hostile intent and other possibilities are: 1) Military reconnaissance; 2) Scientific; 3) Tourism.
He added that if reports are taken at face value they showed extraterrestrial vehicles had a very wide range of speeds and are stealthy.
Thus, he suggested, we could use this technology, if it exists.
His briefing document lists possible reasons for UFO sightings, including mass hallucinations, US aircraft, atmospheric events and hoaxes, but indicated none provide a fully convincing explanation.
It adds there are some indications that the reported incidents are only the tip of an iceberg and many people do not wish to risk embarrassment and so do not report sightings.
He also noted that the number of reports of strange objects in the skies increased dramatically after the Second World War, with most sightings coming from farmers, policemen, doctors and lovers.
Most people think that UFOs are a recent phenomena (sic) but they are not, he said. There are reasonably reliable reports of strange objects in the skies dating back hundreds of years.
In 1979, an official briefing written by the MoD in preparation for a House of Lords debate on UFOs questioned why aliens would want to visit the Earth.
An unnamed intelligence officer said it would be prudent to consider the number of stars in the universe, the number which might have inhabitable planets and a list of interesting places in the universe that an intelligent community might wish to visit".
He said: A visit to an insignificant planet (the earth) of an uninteresting star (the sun) would probably not occur more than once in a thousand years or so, even if one assumes that every intelligent community made say 10 launches a year.
Thus, he concluded, claims of thousands of visits in the last decade or so are far too large to be credible.
Papers also show the existence of a "Flying Saucer Working Party" within government during 1950-52.
In 1998, one worried member of staff annotated the file to say: Oh dear! This makes our 'no interest' in [flying saucers] look suspect. I know not now but maybe then."
Dr David Clarke, UFO consultant at the National Archives and university lecturer, said: These files also detail the background to the MoDs decision to release these files to the public in the first place, something I had been campaigning for over several years under the Freedom of Information Act.
"Now they have been released at The National Archives they will provide future generations with a fascinating snapshot of an unexplored aspect of contemporary social history.
