America's fascination with flying saucers began in Washington state on June 24, 1947. Businessman and pilot Kenneth Arnold was flying his small plane from Chehalis to Yakima when he spotted what appeared to be a formation of nine strange aircraft traveling near Mt. Rainier. Arnold calculated they were flying at supersonic speeds of at least 1,200 miles an hour, something military aircraft of the day were incapable of doing.
Arnold described the shiny objects as "something like a pie plate that was cut in half with a sort of a convex triangle in the rear" and that they flew "like a saucer if you skipped it across the water." The term "flying saucer" made it into a newspaper headline and the rest, as they say, is history.