The acronym “UFO” has lost a fair amount of its meaning over the years. Once intended as a descriptive placeholder for something spotted in the sky that has yet to be identified, it now evokes images of little green (or grey) men from another planet, solar system, or even galaxy. Like our collective inclination to use the word “literally” figuratively, our use of the word UFO has shaped its definition in the minds of readers and listeners, regardless of the acronym’s initial intent — and because of that, many who seek to seriously investigate reports of unidentified objects in the skies about the United States now use different terms to describe them like UAP (Unidentified Aerial Phenomena).

Time and common usage have a way of doing that to a word: shaping our collective understanding until its origin, and intent, are lost in favor of popular usage. Nice once meant silly or foolish, whereas silly once meant something more along the lines of blessed. Language evolves along with our perceptions, and we tend not to spend much time considering their etymology. In the case of UFOs, for instance, the history of the noun that was once an acronym conveys something important about the mystery it represents — that much of it began where so many other common acronyms do: with the U.S. military.

When American pilots first joined their allies from the Royal Air Force in the skies between the U.K. and Nazi Germany, they called the unusual lights they sometimes saw accompanying them on their missions “Foo Fighters,” and some worried that they could have been some sort of advanced German aircraft. Soon, Foo Fighters evolved into “flying saucers,” that is — until an officer in the U.S. Air Force named Edward Ruppelt coined the acronym U.F.O., short for Unidentified Flying Object, in 1556. Although, to be fair, there is some debate about that, as references to that acronym can be found in military documents dating back to at least 1953. That timeline makes a great deal of sense, seeing as the Air Force stood up Project Blue Book, their first serious investigation into these reports of unidentified aircraft, in 1952.

One of the incidents Project Blue Book was tasked with investigating came from the account of a decorated World War II aviator that had gone on to serve in the North Dakota Air National Guard after the war. A 27-minute engagement between that pilot, George F. Gorman, and an unidentified flying object in the skies above Fargo, North Dakota became known as “the Gorman Dogfight” among investigators, though that investigation remains classified for years after it was concluded.

Gorman was behind the stick of a P-51 Mustang on October 1st, 1948, and as the other pilots landed their own fighters, Gorman opted to remain airborne in order to get some more night flying in under the fairly clear and safe conditions. World War II saw not only heavy night-fighting in the sky but served as the first war that truly included night operations for pilots, making the request not an uncommon one for veterans of the conflict. He swung out away from Hector Airport where the other pilots had landed, circled over a well-lit nearby stadium and began his approach back to the airstrip. He could clearly see another airplane, a Piper Cub, flying about 500 feet below him and confirmed its presence with radar operators at Hector… but then he spotted something else. Gorman reported what he believed to be a light from the tail of another aircraft passing by him on the right, but radar controllers told him they had no other aircraft on their scope.

Radar defeating stealth aircraft, of course, wouldn’t be invented for nearly another thirty years, so Gorman’s report immediately seemed unusual. Gorman, recognizing this, opted to close with the light and investigate, bringing his prop-driven fighter to within about a thousand yards of the strange light.

“It was about six to eight inches in diameter, clear white and completely without fuzz at the edges,” the seasoned pilot wrote in his report. “It was blinking on and off. As I approached, however, the light suddenly became steady and pulled into a sharp left bank. I thought it was making a pass at the tower.”

Gorman went after the light, but when he finally got behind it, it turned sharply and was suddenly closing with Gorman’s P-51. Gorman put his plane into a dive to avoid a collision, with the light passing directly over the canopy of his cockpit. As Gorman reoriented himself once more to see the strange craft, it rapidly changed direction again. Gorman didn’t have a chance to react to avoid the impact in time, but just before the strange light hit him, it changed course once more, shooting directly up into the sky. Gorman attempted to follow suit, but the angle of climb was too steep, and he forced the P-51’s engine to stall. Just like that, the Gorman Dogfight was over, but the questions raised that night persist to this day.