The Kenneth Arnold UFO sighting occurred on June 24, 1947, when private pilot Kenneth Arnold claimed that he saw a string of nine, shiny unidentified flying objects flying past Mount Rainier at speeds that Arnold estimated at a minimum of 1,200 miles an hour.
He later described them as a series of objects with convex shapes, though he later revealed that one object differed by being crescent-shaped. Several years later, Arnold would state he likened their movement to saucers skipping on water, without comparing their actual shapes to saucers, but initial quotes from him do indeed have him comparing the shape to a “saucer”, “disc”, “pie pan”, or “half moon”, or generally convex and thin.
Arnold said the objects flew in a diagonally stepped-down, echelon formation, stretched out over a distance that he later calculated to be five miles.
This was the first post-World War II sighting in the United States that garnered nationwide news coverage and is credited with being the first of the modern era of UFO sightings, including numerous reported sightings over the next two to three weeks.
Arnold’s description of the objects also led to the press quickly coining the terms flying saucer and flying disc as popular descriptive terms for UFOs.
Kenneth Arnold UFO Sighting