Parker, ArizonaJune 1955

On June 4, 1955, near Parker, Arizona, a civilian on the ground and a military pilot flying overhead reported seeing an unusual object in the evening sky. The civilian watched through binoculars and described a round object with yellow, white, and red coloring. The pilot, flying a T-33 trainer jet from Laredo Air Force Base in Texas, reported the same object but said it appeared colorless to him. Both observers noted that the object seemed to vanish abruptly.

The sighting drew attention because of something the pilot noticed: his instruments went haywire. His magnetic compass and slave gyro (a navigation instrument that corrects flight heading) began acting erratically. The slave gyro precessed at a rate of twenty degrees every twelve miles as the pilot passed over the location where the object was reported. The pilot also experienced continued navigation errors for the rest of the flight until he reached his destination at Norton Air Force Base in California.

Investigators looked into the incident carefully. They noted that a Constellation airliner was in the area at roughly the time of the sighting, and another military aircraft in the region reported an unusual cloud formation that caught sunlight in a strange way. The Air Force concluded that the sighting was probably caused by the planet Jupiter, viewed through the peculiar lighting effect created by the clouds and sunset conditions. The extreme disturbance to the aircraft's instruments was noted as not uncommon in that particular location, though the exact cause remained unexplained.

The full case file is reproduced below as held by the National Archives, 13 pages.