The first reports of 'flying saucers' being sighted were on 24 June 1947 from the Cascade Mountains of Washington state, USA. A private pilot, Kenneth Arnold, reported seeing nine strange objects that moved at tremendous speed across the sky 'like a saucer skipping on water'. His sighting triggered a wave of similar reports from observers in North America and across the world. On 8 July 1947 a report came from Roswell, New Mexico, that a disc-shaped object had landed on a remote ranch and had been removed for examination by officers from the US Eighth Army Headquarters. The age of the flying saucer had arrived.
The acronym UFO is an abbreviation for the US Air Force term 'Unidentified Flying Object.' It was coined in 1950 by Captain Edward Ruppelt of 'Project Blue Book', the USAF's official 'UFO project', to replace flying saucers, a term that was widely used by the media and public. A flying saucer is defined in the Oxford English Dictionary as 'a disc or saucer-shaped object reported as appearing in the sky and alleged to come from outer space'.