Project 10073 Record Card — Derby, Colorado, 1958

This document details an investigation into a reported unidentified flying object captured on a 35mm slide by a civilian in Derby, Colorado. The witness, who had taken photographs of a B-47 vapor trail between 18 September and 20 October 1958, noticed a red dot on one of the slides upon projection that was not visible at the time of the photograph. The witness reported that the photo was taken in the evening, facing southwest, and that no other aircraft were in the air. The slide was submitted to the 14th District Office of Special Investigations (OSI) and subsequently forwarded to the Air Technical Intelligence Center (ATIC) for analysis. The ATIC photo laboratory examined the slide and concluded that the red dot was not an aerial object, but rather a physical perforation of one or two layers of the film's emulsion. The report notes that when the slide is held at an angle to a light source, a small rise with a pit at the center is visible, confirming the defect. The slide was subsequently returned to the contributor by Major Lawrence J. Tacker of the Office of Information Services.