PROJECT 10073 RECORD CARD - 8 December 1957

On December 8, 1957, a pilot and radar observer from the 29th Fighter Interceptor Squadron, flying an F-89 aircraft near the Montana-Canadian border, reported a sighting of an unidentified aerial object. The pilot, at an altitude of 40,000 feet, observed a spherical, gold-colored object approximately 52 feet in diameter. The object appeared to maintain a position relative to the aircraft during a port turn, exhibiting a black streak on its inside. The sighting lasted approximately 12 minutes. The pilot noted that the object remained with him even after he returned to a different heading, though it occasionally dimmed or became more opalescent. During the encounter, the aircraft's 3-phase inverter malfunctioned, requiring a switch to the spare. Ground radar units, specifically the 778th ACWRON, were queried but reported no other contacts in the vicinity. Visual observers from the 778th ACWRON confirmed seeing the F-89 and its contrails but observed nothing else. Following an investigation, the official conclusion reached by the Air Technical Intelligence Center was that the object was a probable reflection of sunlight off the aircraft, which intersected with a shadow cast upon the contrail. This effect, combined with the sun's position at the time of the turn, created the appearance of a moving spot. The report notes that while initial theories suggested a shadow of the contrail or aircraft, subsequent analysis of weather data and ground observations led to the final determination.