Project 10073 Record Card and Incoming Staff Message regarding 28 May 1962 Sighting

On 28 May 1962, multiple flight crews operating over the northwestern United States, specifically Montana, reported a sighting of an unidentified aerial phenomenon. The object was described as a white, bright, light-emitting entity that appeared to be burning, with pieces falling off as it traveled from north to south at a very high speed. The object was observed by several aircraft, including United Air Lines flights 801 and 729, as well as a C-135 aircraft out of Minot Air Force Base. Observers noted that the object did not exhibit any maneuvers and left no trail or exhaust. Despite the high-speed nature of the sighting, no radar acquisitions were reported. Official military assessment concluded that the object was a meteor of the fireball class, explicitly ruling out satellite re-entry. While a 60-foot plastic balloon was reported loose in the vicinity of Sheridan, Wyoming, investigators noted that the speeds reported by the flight crews did not align with known wind velocities, leaving some ambiguity regarding the balloon hypothesis.