On the afternoon of June 24, 1947, private pilot Kenneth Arnold was flying from Chehalis to Yakima, Washington, and made a detour near Mount Rainier to look for a crashed Marine Corps transport plane. Shortly before 3 p.m., at about 9,200 feet, he saw bright flashes like sunlight off a mirror.
The flashes came from nine objects flying in a long chain north of Mount Rainier. Arnold ruled out geese and reflections on his own windows, timed the objects between Rainier and Mount Adams and worked out a speed of at least 1,200 miles per hour, far faster than any aircraft of the day.
Arnold said the objects moved like a saucer skipped across water. Newspapers turned that into "flying saucers", and within weeks hundreds of similar reports came in across the United States. The sighting is usually counted as the start of the modern UFO era.
