Washington, D.C., April 1952April 1952

A geologist working for the U.S. Geological Survey submitted a photograph to the Air Force in April 1952. The photo had been taken on the evening of April 2, 1952 at 2330 hours (11:30 p.m.) using a 20-minute time exposure. The photographer circled an object visible in the image and asked the Air Force to identify it. Because the picture was a long time exposure, the geologist reasoned that the object could not have been an airplane, since moving aircraft or car lights would have left streaks on the print.

The Air Force's Technical Analysis Division requested the original negative for examination. After analyzing it, their photography section concluded that the "object" was not caused by an actual thing in the sky. Instead, they determined it was a photographic flaw. The most likely explanation, they wrote, was a slight abrasion on the negative that created what photographers call a "faille-mark." This mark could also have resulted from a small speck of developer (the chemical used to process film) becoming stuck to the negative during development, or from improperly controlled developer temperature or chemical strength.

The Air Force's analysis found that the density (darkness) of the supposed object differed from the surrounding sky by only a small margin, which suggested it would not have been visible to the naked eye even if it had been a real object in the sky. They commended the photographer's initiative and cooperation in submitting the image for analysis.

The Air Force evaluated this case as "unknown." The full case file as held by the National Archives is reproduced below across 7 pages.