UFO freaks sighted in London

In 1947, Kenneth Arnold, an American pilot, observed "a chain of nine peculiar-looking craft" in the sky over the Cascade Mountains, in Washington state. Reporting this curious event, a local newspaper coined the term "flying saucer".

Yesterday, the 50th anniversary of the first sighting of an unidentified flying object was celebrated at a conference in London.

Disciples of "ufology" converged on the "unconvention", held by Fortean Times, the journal of the paranormal.

Among the speakers was Patrick Huyghe, a New York expert on UFOs, who has written a field guide to alien life forms. He explained that the popular image of the extraterrestrial - a small grey creature with bulbous head and bulging eyes - had been prevalent only since the late Seventies.

Budd Hopkins, another American delegate, has achieved celebrity status for documenting what he claims is the only case of an alien abduction observed by witnesses. Two police officers and a woman on the Brooklyn Bridge in New York are said to have watched as Linda Napolitano was beamed through the window of her Manhattan apartment and into a waiting spacecraft.

Unfortunately, she has since died and the policemen have never been identified.

There was much else at the two-day conference to enthral devotees of strange happenings, including a report on a spate of mutilations of wallabies at a Cornwall zoo, allegedly carried out by a Satanic sex ring and connected to sightings of a 3ft-high mouse.

Richard Wiseman, a professor of psychology, showed secret footage which he said debunked the Indian rope trick - where the performer shins up an apparently free-standing rope and disappears in a puff of smoke.

A Japanese crypto-zoologist, specialising in the study of unclassified animals, presented film of a "lake monster" spotted near Papua New Guinea.

"It's very fuzzy," conceded Mike Dash, publisher of Fortean Times. "All you can see are some humps. It might just be a crocodile."