Unexplained sightings

From Roswell to the Tic Tac

1947

Object crashes on a ranch in Roswell, New Mexico, prompting conspiracy theories. US military later says it was a test balloon

1952

“Invasion of Washington”. Also known as the “Big Flap”. Over a two week period a large number of civilians, pilots and radar operators reported sightings in the US capital

2004

The “Tic Tac” incident. Naval aviators video a 40ft-long white oblong off the coast of California

2017

It emerges the Pentagon had a $22million (£18million) secret programme to investigate UFOs

2021

Pentagon releases UFO report