Los Alamos, N. M., December 1950 - Incident Number: [ILLEGIBLE]December 1950

On the evening of December 24, 1950, a bright, glowing object appeared in the sky above Los Alamos, New Mexico, an atomic research facility. An observer stationed at the junction of roads 75 and West Road saw the object for about two to three seconds. It was shaped like a sphere with a tail and traveled from the southeast toward the northwest before disappearing behind nearby hills.

The object glowed very brightly with a notable green tint. The observer described it as a bright glow similar to hot metal. It had a tail roughly four times as long as the sphere's diameter, and the tail appeared to be the same color as the main object. The observer noted the object was larger than other visible objects in the sky, though the exact size was unknown. The object moved on a slight downward arc before vanishing from sight.

The phenomenon was reported through official channels to Air Materiel Command at Wright-Patterson Air Force Base in Ohio and to the Office of Special Investigations at Kirtland Air Force Base in New Mexico. The investigating officers noted that while the sighting fell outside normal reporting parameters, the reasonable questions it raised justified forwarding it up the chain of command. The file does not specify whether the Air Force reached a final conclusion about what was observed.

The complete case file, consisting of 12 pages, is reproduced below as held by the National Archives.