Who was Kenneth Arnold and what did he see?

“On 24 June 1947, civilian pilot Kenneth Arnold reported nine saucer-like objects flying in formation near Mount Rainier, Washington at an estimated 1,200 mph. His description gave the press the term 'flying saucer' and launched the modern UFO era.”

Kenneth Arnold was a civilian pilot from Idaho who reported a sighting on 24 June 1947 that is widely considered the founding event of the modern UFO era. While flying his CallAir A-2 from Chehalis to Yakima, Washington, Arnold observed nine bright objects flying in formation near Mount Rainier at an estimated speed of 1,200 mph. He described them to reporters in Pendleton, Oregon as moving "like a saucer would if you skipped it across the water" — a descriptive simile the press collapsed into the now-iconic term "flying saucer." The sighting predated the Roswell incident by two weeks and is the immediate precedent for the December 1947 Wright Field AMC memorandum (PURSUE-023) that acknowledged "continued and recent reports from qualified observers." The Arnold sighting itself is not in PURSUE Release 01 but is the originating event for the broader catalog.