Project 10073 Record Card and Associated Correspondence — Sacramento, California, September 3, 1952

This document comprises a Project 10073 record card and a detailed observer questionnaire regarding a UAP sighting on September 3, 1952, in Sacramento, California. The witness, Irene Carlson, reported observing a single, disc-shaped object from the California-Western Building. The object was described as initially dark black in color, later appearing as shimmering silver, and was noted to be moving very fast in a northerly direction at an estimated altitude of 5,000 to 10,000 feet. The witness, who was on duty at a Ground Observer Corps (GOC) post, reported the sighting for approximately five minutes. A significant detail provided in the observer's additional comments is that a bi-motor airplane crossed the path of the object at the same altitude, moving in the opposite direction. As the plane passed, its starboard motor emitted dark smoke. The incident was reported to the Sacramento Filter Center. The official record card indicates the sighting was for an instant, though the questionnaire clarifies the duration was five minutes. The report includes sketches of the object's path and shape, as well as its appearance relative to the horizon. The case was processed by the Air Technical Intelligence Center (ATIC) under the project designation 10073.