An international panel of retired pilots and aviation officials has risked ridicule by sharing their personal stories of close encounters with unidentified flying objects, and urging the US government to reopen its investigation into extra-terrestrial spacecraft.
Among the UFO incidents discussed by the gathering in Washington DC this week was an alleged sighting of a triangular-shaped flying machine with unfamiliar markings near the former US air base at RAF Woodbridge in Suffolk in 1980.
"Nothing in my training prepared me for what we were witnessing," James Penniston, a retired US Air Force pilot, told the panel. He said the UFO, with "blue and yellow lights swirling around the exterior", was "warm to the touch and felt like metal". Finally, "it shot off at an unbelievable speed" in front of 80 witnesses. "In my log book, I wrote 'speed: impossible'," Mr Penniston added. At the time, the case was labelled the "English Roswell" - referring to the furore caused by the alleged discovery of UFO parts in New Mexico in 1948.
A former fighter pilot from Iran, Parviz Jafari, recalled trying to fire upon what he thinks was a UFO hovering over Tehran in 1976. He inflicted no damage however because, as he approached the target, he said, "my weapons jammed and my radio communications garbled".
The group argued that even the possibility that spaceships may be out there implies a hazard to civil aviation and a security risk that should be taken all the more seriously after the 11 September, 2001 terror attacks.
Jean-Claude Duboc, a former Air France pilot, recalled spotting "a huge flying disc" about 1,000ft (305m) across which left no image on his radar as he flew over Paris in broad daylight in January 1994. He said the object started to become transparent and, within 10 to 20 seconds, had vanished without a trace.
"I observed with my crew a UFO in broad daylight near Paris," he later said.
Believers in UFOs contend that the US and British governments have covered up evidence of alleged galactic incursions. Sceptics insist these "sightings" are caused by natural phenomena such as meteors. But that explanation is not good enough, according to Fife Symington, a former governor of Arizona who was also a panel member.
He said it was time for the Bush government to reopen Project Blue Book, the US Air Force inquiry into 12,500 UFO reports, which was abandoned as a "waste of time" in 1969. "Incidents like these are not going to go away," said Mr Symington. "We want the government to stop perpetuating the myth that all UFOs can be explained away in down-to-earth, conventional terms."
Talk of flying saucers resurfaced in the American media a few weeks ago when one of the Democratic presidential hopefuls, Dennis Kucinich, claimed during a televised debate that he had seen one. His comments may not have been total political suicide - two former US presidents, Ronald Reagan and Jimmy Carter, each spoke early in their careers of remembering encounters with UFOs.
Several of the 19 pilots and former officials on the panel, drawn from seven countries, offered vivid descriptions of apparent encounters with alien craft. But, while all appeared to have firm grips on their sanity, there is little chance of the US government paying them the slightest attention, despite their anger and collective protestations.