Unidentified Flying Object ( UFO ) is any flying object or phenomenon that cannot be identified by the observer. Also commonly known as alien spacecraft.
The files contain a wide range of UFO-related documents covering the years 1978–2002. So if you want to find out more about lights in the sky over Waterloo Bridge, near misses by pilots, crop circles - and what the UK government thought of it all - this is the place to start.
On a related note, NASA announced the discovery of an object in our Galaxy astronomers have been hunting for more than 50 years but no evidence of aliens or an asteroid that will wipe out the Earth found.