June 24, 1947: They Came From ... Outer Space?

Pilot Kenneth Arnold sights a series of unidentified flying objects near Washington's Mt. Rainier. It's the first widely reported UFO sighting in the United States, and, thanks to Arnold's description of what he saw, leads the press to coin the term flying saucer.

Arnold was an experienced pilot with more than 9,000 hours of flying time. He had diverted from his flight plan -- Chehalis to Yakima, Washington -- to search for a Marine Corps C-46 transport plane reported down in the Cascades near the southwest slope of Mt. Rainier. A sweep of the area revealed nothing, and Arnold resumed his original course.

As Arnold recalled, the afternoon was crystal clear, and he was cruising at an altitude of 9,200 feet. A minute or two after noting a DC-4 about 15 miles behind and to the left of him, he was startled by something bright reflecting off his plane. At first he thought he had nearly hit another aircraft but as he looked off in the direction the light had come from, he saw nine "peculiar-looking" aircraft flying rapidly in formation toward Mt. Rainier.

As these strange, tailless craft flew between his plane and Mt. Rainier and then off toward distant Mt. Adams, Arnold noted their remarkable speed -- he later calculated that they were moving at around 1,700 mph -- and said he got a pretty good look at their black silhouettes outlined against Rainier's snowy peak. He later described them as saucer-like disks … something the gentlemen of the press glommed on to very quickly.

At the time, Arnold said, the appearance of these flying saucers didn't particularly alarm him, because he assumed they were some kind of experimental military aircraft. If they were, nobody in the War Department (soon to be merged into the Department of Defense) was saying.

In fact, the official Army Air Corps position was that Arnold had either seen a mirage or was hallucinating. He insisted he was perfectly alert and lucid, adding that he was not a publicity hound, either. He also invited both the Army and the FBI to investigate. The Army sent a couple of officers out to talk with Arnold. Even though they concluded that "a man of [his] character and apparent integrity" almost certainly saw what he claimed to have seen, the Army's initial verdict remained unchanged. - wired

He was right, they were military experimental jet aircraft, the great grandfathers of today's stealth craft.