Los Alamos, New MexicoJune 1949

On the evening of June 11, 1949, a security inspector at Los Alamos, New Mexico, spotted an unusual light in the clear night sky at 8:57 p.m. The object appeared as a bright star or point of light located roughly southwest of the observer, at an elevation of about 25 degrees above the horizon. It was visible for only one to five seconds.

During its brief appearance, the object changed color from green to red and displayed a short red tail. It climbed sharply upward and then fell almost straight down before seeming to go out. The observer estimated the object was 20 to 30 miles away. The Air Force investigator noted that the observer did not believe the object was a meteor, pointing to its unusual color and flight path as reasons for this assessment. There was no sound or odor associated with the sighting. The observer, who met security clearance requirements for employment at Los Alamos, wore no special eyeglasses at the time and did not view the object through any window or transparent material.

The Air Force's official evaluation of this case was "unidentified," meaning investigators could not determine what the object was. The full case file, consisting of 6 pages as held by the National Archives, is reproduced below.