Van Nuys, Calif., July 1948 - Incident Number: 163July 1948

On the evening of July 21, 1948 (corrected from the initial July 22 report), a clear, stationary object appeared in the sky above Van Nuys, California, drawing the attention of multiple observers over the course of an hour. The primary witnesses were a husband and wife dining in the area who saw what they initially thought might be a weather balloon at about 2,000 feet, except it lacked the characteristic bobbing motion of such balloons. As the sun set, the object's color shifted from a bluish luminescence resembling a fluorescent lamp to an orange hue, before cutting off suddenly like a switch being thrown. The outline remained sharp and symmetrical throughout the observation.

Professional astronomers at Mount Wilson Observatory and Griffith Observatory in Los Angeles also tracked the object through telescopes. They described a pear shaped structure with what appeared to be a translucent outer envelope enclosing a sphere, and a rectangular metallic disk suspended beneath it by cords or cables. The observers estimated the object at roughly 20 to 25 feet in diameter and approximately 20,000 feet in altitude. The object moved slowly and steadily toward the west as it passed overhead, maintaining consistent brightness by reflecting sunlight until it moved into the Earth's shadow after sunset.

An official Air Force investigation in September 1948 included interviews with the civilian witnesses and the astronomers, as well as checks of weather records and balloon releases in the Los Angeles area. The investigators found no record of any meteorological balloon launches that would account for the sighting, and no other obvious explanation. One observatory assistant initially suggested to the press that it might have been a weather balloon, but later acknowledged he had no basis for that conclusion.

The full case file, comprising 36 pages as held by the National Archives, is reproduced below.