Sacramento, CaliforniaAugust 1949

On the night of August 31, 1949, two U.S. Air Force officers stationed at Mather Air Force Base near Sacramento, California, witnessed an unusual aircraft near their homes about five miles south of the city. At approximately 2217 hours (10:17 p.m.), one officer called the other for help identifying navigational stars. As both men looked toward the north star Polaris, one officer spotted the object and pointed it out. The other officer saw it almost immediately.

The object appeared as a large, dark shape with a dull gray or silver finish. It had a short, rounded nose, very short stubby wings rounded at the tips, and no visible tail. There was no visible exhaust, no navigation lights, and no sound of any kind. The officers estimated the object was about 15,000 feet in altitude and moving at approximately 700 to 800 miles per hour. It traveled in straight, level flight on a heading of about 220 to 230 degrees. The officers watched for roughly three to ten seconds before the object faded into the bright glow around the moon and disappeared from view.

Both officers were experienced pilots and rated as reliable. During their interrogation, they agreed on most details, including the time, direction, and speed. They emphasized that the object was remarkably fast and completely silent, unlike any conventional aircraft they had ever seen. They ruled out the possibility that they had seen a shadow, since the object had clearly blocked out stars beneath it as it passed overhead. An earlier report of similar sightings at the base prompted the Office of Special Investigations to continue its inquiry into the matter.

The U.S. Air Force concluded the sighting was unidentified. The complete case file, consisting of 15 pages as held by the National Archives, is reproduced in full below.