June 24, 1947 — Private pilot Kenneth Albert Arnold (1915-1984), experienced businessman and Eagle Scout with 4,000+ hours of flying time, was piloting his CallAir A-2 from Chehalis to Yakima, Washington. While looking for a crashed Marine Corps transport near Mount Rainier, he spotted nine shiny objects flying in a chain formation past the mountain. WHAT HE SAW: Nine bright objects flying from Mount Rainier toward Mount Adams — a distance of ~50 miles — which he timed at approximately 1 minute 42 seconds = estimated speed of 1,200–1,700 mph. In 1947, no aircraft had yet broken the sound barrier (Chuck Yeager did so on October 14, 1947 — months later). The objects flew in a diagonal chain, fluttering and skipping, tipping their wings alternately. Arnold compared their MOTION (not their shape) to “a saucer if you skip it across water” — but AP reporter Bill Bequette’s story used “saucer-like” to describe their shape instead, giving birth to the term “flying saucer.” THE TERM: Arnold explicitly stated he never said the crafts were saucer-shaped. By afternoon the phrase had spread nationwide. Within three weeks: 850+ similar reports flooded the US and worldwide. OFFICIAL RESPONSE: Army Air Forces officially said “mirage” — but secretly, AAF intelligence (with FBI) began a classified investigation. Conclusion within weeks: “The saucer reports were not imaginary or adequately explained by natural phenomena; something real was flying around.” This led to Project Sign (1948), then Project Grudge (1949), then Project Blue Book (1952-1969). Arnold’s sighting occurred two weeks before Roswell — the two events together launched modern ufology.