San Antonio, TexasAugust 1953

On August 5, 1953, at 10:00 a.m. Central Standard Time, four civilians working near San Antonio, Texas saw an elliptical-shaped silvery object hovering silently in the sky. The object appeared to vary in size depending on the observer, ranging from about the size of a quarter to the size of a number two washtub. The witnesses watched it for approximately five to eight minutes as it remained nearly motionless above them, positioned due west of their location. Fair weather and unlimited visibility prevailed at the time. No sound was heard, and the object showed no signs of exhaust, vapor trails, or aerodynamic features.

The observers were employees or family members connected to work at San Antonio. They immediately reported the sighting to nearby Kelly Air Force Base. The investigation confirmed that weather balloons had been launched that morning, with one sent aloft at 0930 hours and reported to have reached 23,349 feet by 1532 hours that afternoon. When asked about the object, the Air Force initially favored the explanation that it was a weather balloon reflecting sunlight. However, the file notes that the reliability of the observers was unknown, and the base also requested wind data aloft at 75,000 feet to better evaluate whether the sighting could be explained by atmospheric conditions or known aircraft.

The case file contains detailed witness statements and a standardized observer questionnaire with sketches and diagrams attempting to capture the object's size, shape, and movement. Despite these records, no definitive explanation emerged. The Air Force's conclusion listed the sighting as unidentified, though earlier communications had speculated it was likely a balloon or aircraft. The full case file is reproduced below as held by the National Archives, consisting of 19 pages.