On June 24th, 1947, while flying near Mt. Rainier in Washington State, Kenneth Arnold, American aviator and businessman, claimed to have seen nine unusual objects flying in the skies. Arnold also claimed to have seen UFOs on several subsequent occasions.

Arnold originally described the objects’ shape as “flat like a pie pan”, “shaped like a pie plate”, “half-moon shaped, oval in front and convex in the rear”, “something like a pie plate that was cut in half with a sort of a convex triangle in the rear”, or simply “saucer-like” or “like a big flat disk”, and also described their erratic motion being “like a fish flipping in the sun” or a saucer skipped across water. From these, the press quickly coined the new terms “flying saucer” and “flying disc” to describe such objects, many of which were reported within days after Arnold’s sighting. Later Arnold would add that one of the objects actually resembled a crescent or flying wing.

The U.S. Air Force formally listed the Arnold case as a mirage; this is one of many explanations that have been disputed by critics, and researchers Jerome Clark, author of The UFO Book (1998) and Ronald Story, editor of The Encyclopedia of UFOs (1980). Both argue that there has never been an entirely persuasive conventional explanation of the Arnold sighting.

After his UFO sighting, Arnold became a minor celebrity, and for about a decade thereafter, he was somewhat involved in interviewing other UFO witnesses or contactees. Notably, he investigated the claims of Samuel Eaton Thompson, one of the first contactees. Arnold wrote a book and several magazine articles about his UFO sighting and his subsequent research.

By the 1960s, Arnold had little to do with UFOs, and eventually declined all interviews. On June 24, 1977, however, he attended the First International UFO Congress in Chicago, curated by Fate to mark the 30th anniversary of the “birth” of the modern UFO age. Some of his comments at the event reflected his displeasure at the general ignorance concerning the matter:

… well, right here we’ve seen something, I’ve seen something, hundreds of pilots have seen something … in the skies. We have dutifully reported these things. And we have to have 15 million witnesses before anybody is going to look into the problem … seriously? Well this is utterly fantastic. This is more fantastic than flying saucers or people from Venus or anything as far as I am concerned.