ODESSA, WASHINGTONDecember 1952

On the night of December 10, 1952, two pilots of an F-94 fighter jet flying near Odessa, Washington, at approximately 26,000 feet spotted a large white object with a dim reddish-white light. The object appeared larger than any known aircraft and seemed to have two "windows" emitting the light. The pilots saw the object for about 15 minutes. It reversed direction almost instantaneously, performed sharp turns toward the aircraft, and at one point appeared to be on a collision course, prompting the pilot to bank away. The radar operator aboard the F-94 tracked the object on the plane's airborne radar (APG-33) while this was happening, though the visual and radar contacts did not perfectly coincide.

The Air Force initially considered that the object might have been an upper air research balloon. These balloons, made of translucent polyethylene and capable of expanding to 90 feet in length at cruising altitude, could theoretically match the size description and produce radar returns. However, the Air Force had received no records of balloon launches on that date. Two other F-94s were in the area but at lower altitudes and were ruled out as the source of the sighting.

A later review of the evidence by other analysts suggested a more likely explanation. The night was clear above 3,000 feet with no moon, and the star Sirius was just rising in the east at the exact bearing where the object appeared. Atmospheric refraction caused by weather conditions could have created the visual phenomenon described, and the same conditions would have produced anomalous radar returns, accounting for the radar contact as well.

The Air Force initially designated this sighting as unidentified, though subsequent analysis pointed to the astronomical explanation. The full case file, comprising 21 pages held by the National Archives, is reproduced below.