Louisville, KentuckyNovember 1954

On the afternoon of Friday, November 12, 1954, people across Louisville, Kentucky, and surrounding areas looked up to see a gleaming white object hanging motionless at an estimated 80,000 feet in the sky. Over the course of several hours, the object slowly changed color. It turned yellow, then red, before finally fading as darkness fell. The sighting was so striking that military officials scrambled to investigate, and newspapers and radio stations fielded calls from curious residents throughout the day.

A jet fighter from Wright-Patterson Air Force Base in Dayton, Ohio, was dispatched to identify the object. The pilot climbed to about 40,000 feet but could not reach the object to get a closer look. Similar mysterious sightings were also reported over Knoxville, Tennessee, around the same time. A physicist attending a conference at the Air Force base visited Air Force officials to describe what he had seen over Knoxville. He called the object transparent and round, hovering at very high altitude. He noted that he could see only the exhaust trails from two jets that seemed to pass near it, not the jets themselves. The physicist said he suspected the object was probably a balloon, but wanted official confirmation.

Within days, Air Force investigators traced the sightings to their source. The University of Minnesota, in cooperation with the U.S. Office of Naval Research, had released two large plastic research balloons on November 12 and 13. One balloon measured 90 feet in diameter and was 100 feet long. The Air Force concluded that the objects seen over Louisville and Knoxville were these high-altitude research balloons launched for atmospheric study, not unidentified flying objects. The case file notes that the balloons matched observers' descriptions of the behavior they witnessed.

The complete case file, comprising 9 pages of original Air Force records, is reproduced below as held by the National Archives.