On the afternoon of June 24, 1947, amateur aviator Kenneth Arnold was flying near Mt. Rainier, Washington, when he suddenly spotted nine unusual objects on the horizon. Arnold claimed the craft flitted from side to side and flipped in unison like “the tail of a Chinese kite,” and he estimated they were moving at around 1,700 miles per hour—far faster than any known aircraft. He initially assumed the physics-defying objects must be secret military vehicles, but he later admitted the incident was “as much a mystery to me as it is to everybody else.”
Arnold’s extraordinary story soon found its way into newspapers across the country, and reporters pounced on his description of the objects as moving “like a saucer if you skip it across water.” Within days, the term “flying saucer” was born.
Coupled with the famed July 1947 incident at Roswell, New Mexico, when the Air Force claimed a military weather balloon was mistaken for an alien spacecraft, Arnold’s encounter helped spark a wave of “flying saucer” sightings across the United States. The military brushed aside most of these “close encounters” as misidentifications or mere hokum, but a few reports came from air-traffic controllers and commercial pilots—people trained to search the skies with a discerning eye. The hysteria also dovetailed with the beginning of the Cold War, leading many to speculate that the mysterious sightings might be hostile Soviet aircraft.