Unidentified Flying Object Report (FLYOBRPT) — Sonoma, California, 10 January 1953

This Air Intelligence Information Report, dated 20 January 1953, details an Unidentified Flying Object (UFO) sighting that occurred on 10 January 1953 near Sonoma, California. The report was prepared by Captain Percy V. Haug of the Western Air Defense Force (WADF) at Hamilton Air Force Base. The primary witnesses were a retired USAF Colonel and an employee of the Federal Security Agency. According to the report, the witnesses were located on a knoll in the hills northwest of Sonoma when they observed a single, silvery object at a very high altitude. The object was described as being approximately the size of a pinhead held two feet from the eye. The witnesses reported that the object moved at an estimated speed four times that of a jet aircraft and produced a sound similar to an F-86 jet at high altitude, with no variation in tone or volume during its maneuvers. The object's behavior was characterized by three 360-degree right turns, each completed in two to three seconds, followed by two abrupt 90-degree turns. After these maneuvers, the object slowed to a near stop, accelerated again, and then rose vertically until it disappeared from view. The total duration of the observation was estimated at 60 to 75 seconds. The report notes that the 28th Air Division (Defense) confirmed there were no radar contacts in the area at the time of the sighting. Weather conditions were reported as clear with good visibility. In the discussion of the incident, the investigators noted that while a balloon was considered as a potential explanation, the velocity estimates and the nature of the maneuvers did not support that conclusion. The official conclusion provided in the report is simply 'Unknown.' The document includes a reference to a tape recording of the interrogation as an enclosure and is marked as having been downgraded from a restricted classification.