ANDERSEN AFB, GUAM, December 1952December 1952

Early on the morning of December 19, 1952, multiple observers at Andersen Air Force Base in Guam and its surrounding areas reported seeing an unidentified object traveling at extremely high speed. Between 0650 and 0655 hours (roughly 6:50 to 6:55 a.m.), three separate groups of witnesses spotted what they described as a cylindrical or spherical, silvery metallic object. The sightings came from ground crew personnel at Andersen AFB, a Navy officer stationed about 11 miles south of the base, and two B-17 pilots flying about 115 miles west of Guam.

All observers reported the object heading roughly west (270 degrees). They said it moved at a speed far exceeding that of conventional jet aircraft, traveling in level flight without turning or maneuvering. The object appeared to be 100 to 150 feet long and featured a bright silvery white or blue flame streaming from the rear end. Some witnesses estimated the flame extended as much as three times the length of the object itself. No sound, exhaust, or vapor trail was heard or observed. Each sighting lasted no longer than 45 seconds. The object disappeared from view when it passed behind clouds in each instance.

The investigating Air Force officers found the witnesses credible. The two B-17 pilots had considerable flying experience, and one was a weather officer who ruled out a meteorological phenomenon. The three airmen on the ground, though less trained in aircraft identification, were confident the object was not a meteor, since it traveled in a perfectly level, horizontal path rather than following the curved downward trajectory of a falling star. All local aircraft had been accounted for. The Air Force noted that a scheduled weather balloon launch had occurred at Guam near the time of the sighting, but the object's description did not match a typical balloon.

The file concludes with the determination "Unknown." No satisfactory explanation is recorded for the sightings beyond the observation that the object's behavior and appearance were consistent across all three observation points.

The full case file is reproduced below as held by the National Archives, comprising 28 pages.