Historians of the modern flying saucer phenomenon typically date its emergence to the start of the Cold War and to Kenneth Arnold’s 1947 sighting of nine flat, saucer-like discs near Mount Rainier, Washington.1 The event is recorded as the Kenneth Arnold Unidentified Flying Object (UFO) sighting, also referred to as the 1947 Mount Rainier sighting. Arnold said he was a businessman whose sighting became known in the press as “flying saucers”,2 and that he had taken his plane up as a private pilot to search for a downed US military transport aircraft, hoping to win a $5,000 reward, when it occurred.3
According to Arnold’s own account, he first saw a brilliant flashing light in the distance, which he worried might be another aircraft,4 then made out a series of bright flashes north of Mount Rainier from a distance of 30 to 40 kilometres.5 He watched the objects fly toward the mountain and pass in front of its snow-covered slopes,6 describing their shape as convex, with one object appearing crescent-shaped.7
On 23 June 1947, Arnold saw nine large circular objects flying in formation that periodically flipped as they passed near Mount Rainier.8 As an experienced pilot accustomed to judging the speed of distant aircraft,9 he estimated the objects were travelling at approximately 2,700 kilometres per hour.10 He compared their flight to the “tail of a Chinese kite”11 and described the objects themselves as “saucer-like aircraft”.12 When later asked by a reporter how they had flown, Arnold said their motion was like saucers skipping over water.13 The account was picked up by several media outlets, and the term “flying saucer” emerged from it.14
Project SAUCER investigated the account Arnold provided,15 and segments of the American public have been interested in the UFO/UAP topic since the term “flying saucer” emerged following the sighting.16 Chris Ramsay has said that the sighting, together with the Roswell Unidentified Flying Object (UFO) crash and the Aztec crash, prompted government and military interest that led to the formation of Project GRUDGE, which later became Project Blue Book.17 Major Murphy has said that General James Doolittle’s involvement in a 1946 investigation in Sweden - a year before Arnold’s sighting, and before the United States Air Force (USAF) itself existed - reflected considerable interest in the topic among senior military figures even before the creation of Project Blue Book.18
Luis Elizondo has said that after the sighting - which took place a couple of weeks before the 1947 Roswell Unidentified Aerial Phenomena (UAP) crash - Arnold and his family allegedly experienced balls of light appearing in their home.19