On 24 June, 1947, Kenneth Arnold, a successful salesman and experienced search and rescue pilot, took off in his small plane from Chehalis, Washington en route to Yakima. Close to Mineral, Washington and about 25 miles from Mount Rainier, he noticed a formation of 9 unusual objects flying from north to south at around 9,500 feet. He observed the objects strange flight characteristics for 2 to 3 minutes and calculated their speed at over 1,200 m.p.h.
When Arnold landed at Yakima, Washington, he told some people of the incredible new high speed aircraft he had witnessed. He flew on to Pendleton, Oregon and found a number of reporters were waiting, eager to learn about these new aircraft.
Asked to describe how they flew, Arnold explained that, "they flew like a saucer would if you skipped it across the water". A reporter named Bill Begrette coined the phrase "flying saucer" and people have been claiming to see "flying saucers" ever since!
But curiously, Kenneth Arnold did not actually describe a saucer shaped craft and "flying saucers" are by no means the only phenomenon consistently described in reports.