London - They were shaped like cigars, saucers, coffins and amorphous blinking blobs. They hovered in a menacing manner, traveled at impossible speeds and vanished into the netherworld, or, in one instance, a hedge in Cornwall.
A few carried humanoid life forms, or so it seemed. A few materialized courtesy of the observers' possibly having had a drink too many, as in the case of an unidentified flying light cluster witnessed loitering in the sky by the patrons of a pub in Kent.
Whatever they were, these phenomena reported to Britain's Ministry of Defense over the years and made public this month were almost certainly not actual alien aircraft piloted by actual alien beings.
"The government has been telling us the truth," declared David Clarke, a senior lecturer in journalism at Sheffield Hallam University, who has a side interest in U.F.O.'s. "There are a lot of weird things in the sky, and some of them we can't explain, but there's not a shred of evidence for a single alien visitation."
Which is, frankly, a letdown, as is the government's prosaic explanation of why, for decades, it has meticulously documented reports of U.F.O. sightings. "We only check the sightings from the perspective of making sure that our military airspace has not been breached, and we pretty much never have airspace breaches," a Defense Ministry spokeswoman said.
The spokeswoman, who spoke on condition of anonymity - not because she works with Agent Mulder in some shadowy basement office, but because that is government policy - said the ministry had begun making the files public because it had been inundated with U.F.O.-related requests under Britain's Freedom of Information Act.
The files from 1978 to 2002 were released this month. Some older files have already been declassified and made public; the rest will be released over the next few years. Available on the Web from the National Archives at ufos.nationalarchives.gov.uk, they cover hundreds of sightings but are hardly the X-Files. Much of the material consists of one-page forms carrying details like how big the supposed aircraft was and what, if anything, it seemed to be doing.
A citizen who gives her profession as "meals on wheels operator" describes her shock and awe at the sight of a smallish "Vulcan-shaped object" hovering in the sky. Another witness says she was roused from bed by a brilliant light emanating from a U.F.O. "the size of a milk-bottle base."
"Some time on a Monday evening during the break in watching 'Quincy' - I checked my watch - I noticed an unusual happening in the sky," one correspondent wrote. And from Cornwall, a report arrived from a 28-year-old motorist who observed a bright yellow light "which bobbed and weaved" over the road, an image recalling Tinkerbell's mode of travel in "Peter Pan."
"The light changed to a purplish color, prior to its exit into a thick hedgerow," the report reads.
The files include random newspaper clippings of questionable journalistic rigor. A 1986 Daily Mirror article reports that the light "from a glowing red object" suffused the cockpit of a Royal Air Force jet carrying Prince Charles, seriously unnerving the pilot. As an aside, the newspaper noted that "Prince Philip has been a keen U.F.O. follower for the past 36 years."
There are long letters asking big questions. "When is a flying saucer not a flying saucer?" muses one correspondent. "And is the mothership man-made or from a distant planet?"
In the old days, the United States systematically compiled reports of U.F.O. sightings, too. But its last program, known as Project Blue Book, was closed down in 1969 after government officials concluded that if something was out there, it was not anything they wanted to investigate.
Some U.F.O. enthusiasts said last week that they believed the British government had not released all of its files and was concealing the truth about a massive cover-up it had long perpetrated on the British people.
But Joe McGonagle, a self-described U.F.O. researcher here, said the documents showed that far from concealing anything, the government had failed to investigate the sightings properly in the first place.
"A lot of people imagined that there was this vast U.F.O. project with lots of people working on it, when in reality it was a civil servant spending 25 percent of his time on it, filing reports," he said.
It is not as if the authorities have always failed to take the issue seriously. In 1950, the government convened a secret committee, the Flying Saucer Working Party, to investigate sightings of U.F.O.'s. It concluded that U.F.O.'s were optical illusions, weather phenomena, airplanes seen from strange angles and the like, which has been the government's line ever since.
In 1979, the House of Lords debated the matter at the urging of the Earl of Clancarty, who believed that man was descended from aliens who crawled from the earth's core via special tunnels or flew in spaceships 65,000 years ago.
He was not the only noble believer.
"I should like to tell your lords about some of the sightings I have seen," said the Earl of Halsbury, "beginning at the age of 6, when I saw an angel."
Lord Gainford said he had seen a U.F.O., which he described as "bright white ball with a touch of red followed by a white cone," at a New Year's Eve party in Scotland. Some children saw it, too, he added, and they "had been drinking soft drinks."
None of their accounts were as detailed as that of a 78-year-old ex-soldier in Aldershot. His story, which he told to a U.F.O. investigator, can be found in the newly released files.
Out fishing in 1983, the man had just poured himself a cup of tea, he recalled, when he was approached by two four-foot-tall beings wearing pale green overalls and large helmets. They led him into what turned out to be their ship - "I thought, Christ - what the hell's that?" he said - and, apparently considering whether to subject him to extraterrestrial experiments, suddenly announced: "You can go. You are too old and infirm for our purposes."
"Anxious to avoid causing offense," the report said, the man asked no questions, even obvious ones like, what planet do you come from? Instead, he returned to the riverbank, where he finished his tea (by then cold) and resumed fishing.
He was reluctant to tell his family, the report says: "I knew my wife would say 'No more fishing for you, old man.' "
