1988 - Puerto Rico. As you can see, this seems to show a jet fighter chasing a discoid / or wedge shaped object with a protuberance on top and bottom. A reader has sent in this info on this picture.
Picture taken by Amaury Rivera. He also took several others after running to his car to get his camera after being abducted at the Laguna Calthena.
1972 - Apollo 16, Moon Mission Dates: April 16-27, CDR: John W. Young, CMP: Kenneth Mattingly, LMP: Charles Duke, Importance: Explored the Moon's rocky central highlands. NASA archives (photo No AS16-109-17804)
Mission Apollo 16 on the Moon. Astronaut John Young on rim of Plum crater gathering lunar rock samples. UFO at top right.
1990 - Wallonia, Belgium - This photograph was part of the Belgian Wave of 1989-1990. Taken by J.S. Henrardi on June 15, 1990. Mr. Henrardi released all copyright ownership to the photograph in 2003, making it available for public use.
The object very closely resembles the Petit Rechain triangle, also part of the Belgium wave. The triangles were reported by hundreds of witnesses during the wave over Belgium.
