1947 Kenneth Arnold sighting

On June 24, 1947, experienced private pilot Kenneth Arnold was flying his CallAir A-2 near Mount Rainier in Washington State when he reported seeing nine bright, highly reflective objects traveling rapidly in formation across the Cascade Mountains. Arnold said the objects appeared flat and tailless, flashing brilliantly as they banked in the sunlight, and he estimated that they were moving at more than 1,200 miles per hour, an extraordinary speed for aircraft of that era. He described their unusual motion as being like a saucer skipping across water—a comparison referring primarily to the way they moved rather than necessarily to their shape. Newspaper coverage of Arnold's account quickly popularized the expression “flying saucer,” and the story spread across the United States, followed by a wave of other reported sightings. Although various conventional explanations have been proposed over the years, exactly what Arnold observed remains disputed. His encounter is widely regarded as one of the events that launched the modern UFO era and permanently introduced the flying-saucer phenomenon into American popular culture.