Hundreds of people saw this object, illuminated by bright lights, flying at a low altitude over a residential part of Levittown, Puerto Rico, in 1980. Police Officer José Cordero took ten photos with his Polaroid camera.
Picture taken by Carlos Diaz on March 23, 1981 in the the Ajusco National Forest, Tepoztlan, Mexico. Diaz claimed to have been abducted by whatever entities were piloting the "craft".
Hannah McRoberts took this picture near Kelesy Bay, on the east coast of Vancouver Island, on October 8, 1981 after seeing a strange cloud over a nearby mountain. It was only when the picture was developed that the disc became apparent.
A picture taken by an East German NVA unit in 1982.
Taken by Felippe Orego showing three lights over the Manhattan skyline, New York, on May 9, 1984.
This display of coloured lights was photographed by a police officer over I-84 near Waterbury, Connecticut, on May 26, 1987 after several cars lost power and stalled.
An American strike aircraft appears to ''duel'' with an object on May 9, 1988 over Puerto Rico.
Photograph taken over Vidnoye, Russia, on May 4, 1989.
An unattributed picture taken on March 10, 1989 in Rio de Janeiro, Brazil.
Taken by an unknown photographer at Stonehenge, Wiltshire, in 1990.
One of several documented cases of triangular craft seen and recorded over Belgium during the 1990s during one of the most famous UFO "flaps" of the last 30 years.
Video shot from the Space Shuttle Atlantis in April 1991 appears to show a metallic object appearing and then swinging in front of the camera.
Photograph of a circular, multi-coloured object 200ft above the over the Kincardine Bridge. The photographer had to lie flat on his back to get this shot.
One of a series of pictures broadcast on Chilean television from footage taken by a satellite over the Pacific showing a huge disc-shaped object over the Earth.
One of a series of photographs taken by Eric Thomason in Maslin Beach, Australia, on March 10, 1993. Mr Thomason said that the object rose out of the sea.
picture taken by Semyon Teglyov in Bogadinski, Kazakhstan, on April 27, 1995.
Joe Clower was photographing some workmen painting the gold balls on a city monument in Denver, Colorado, in January 1996 when he saw a strange bell-shaped object in the sky.
Lajos Kosina took this picture of his girlfriend in the village of Erpatak in Szabolcs-Szatmar, Hungary, in October 1996. The object was not noticed until the photographs were developed.
A Nasa image taken by the Solar Heliospheric Observatory (Soho) spacecraft observing the Sun on January 15, 2003.
Photograph of a lit object taken in the morning in February 2003 in Weyauwega, Wisconsin.
Photograph taken early in the morning over Long Island, New York.