Washington, D.C., December 1961December 1961

On the evening of December 13, 1961, a dark gray diamond-shaped object appeared in the sky above Washington, D.C., traveling from west to east at low altitude. Multiple witnesses reported seeing the craft over the course of three to four minutes. The object was described as sharply outlined, approximately the size of a Piper Cub airplane, with a pulsating orange-brown glow on its underside. One witness, who was stopped in traffic in downtown Washington, reported that the object passed directly overhead and exhibited a defined shape with what appeared to be stepped surfaces on the bottom. The witness noted that the object made no sound, showed no visible means of propulsion, and displayed no navigation lights. The craft appeared to travel in a straight and level course, and two observers at different locations attempted to triangulate the sighting without success.

Hynek, from Northwestern University's Astronomy Department, corresponded with the investigating officer after the sighting. In his letter, Hynek noted that the object's parallax (the difference in apparent position when viewed from different angles) appeared quite large, suggesting the object was flying low. He reported that one observer, a pilot with years of experience, had ruled out a helicopter because the object was clearly low yet showed no signs of rotor blades or propellers. The pilot also noted the absence of navigation lights and any sound. Hynek recorded that the witness questioned whether conventional aircraft or known phenomena could explain what was observed.

The file contains detailed witness testimony forms and technical descriptions submitted to Project Blue Book. Sketches prepared by the witnesses show a stepped geometric shape, with one illustration depicting the object as viewed from below with an orange glow visible at the underside. Weather conditions at the time were clear with good visibility. Air Force officials noted in their report that the sightings appeared reliable but indicated that the cause remained unknown.

The full case file is reproduced below as held by the National Archives, comprising 41 pages of microfilm T1206, Roll 44.