Project 10073 Record Cards and Summary of Information: Oak Ridge, Tennessee (16 & 21 January 1951)

This document collection contains Project 10073 record cards and associated correspondence regarding two distinct incidents over the Oak Ridge, Tennessee, Atomic Energy Commission facility in January 1951. The first incident, occurring on 16 January 1951, involved a visual sighting by five civilians who observed an 'unusually bright' stationary light for approximately five minutes. Plant authorities investigated but found no explanation for the object. The second incident occurred on 21 January 1951, involving an airborne radar contact by an F-82 aircraft from the 52nd Fighter All Weather Group. The radar operator reported an unknown target near the X-10 plant. Despite three attempts to intercept the target, the aircraft could not complete the pass because the target was located over the restricted area. The Air Materiel Command (AMC) subsequently evaluated the radar data and concluded that the target was likely a ground target detected due to 'ducting' caused by a double temperature inversion in the atmosphere. The AMC report explains that the radar energy was refracted to the ground, causing the target to appear to the interceptor pilot as being first above and then below the aircraft. Regarding the visual sighting, the official conclusion stated that due to a lack of factual evidence, no positive explanation could be offered, though several possibilities were considered. The documents include routing sheets, summaries of information, and technical evaluations from the Air Materiel Command, all of which were eventually downgraded and declassified under DOD Directive 5200.10.