Etain AFB, France, July 1958July 1958

On the night of July 11, 1958, military weather observers at Etain Air Force Base in northeastern France saw an unusual object in the sky. The object was egg-shaped, about the size of a grapefruit, and white in color. It traveled in a straight line from south-southwest to northeast, moving fast across the sky. The most distinctive feature was a light that blinked on and off at regular intervals. The entire sighting lasted about 25 seconds before the object blinked off to the north and did not reappear.

The witnesses were credible observers. According to the Air Force report, they included personnel from the 31st Weather Squadron stationed at Etain, who were described as reliable. The object was observed from the base's weather tower during what appears to have been a routine observation. At the same location and around the same time, additional tower operators made similar observations, lending consistency to the report.

The Air Force investigation checked local weather conditions at the time of the sighting. The sky had scattered high clouds and thin overcast, with visibility of about six miles to the south and four miles to the north. Wind data was recorded at various altitudes. Air traffic control was contacted to determine if any aircraft were in the area, and they reported none. Radar operators also reported no radar contact with any foreign object.

After analyzing the sighting, the Air Force concluded that the object was almost certainly Sputnik III, the Soviet satellite that had been launched into orbit in May 1958. At the time and location of the sighting, Sputnik III's rocket body would have been in the vicinity of northeastern France at approximately 165 miles altitude, traveling in a direction consistent with what the witnesses observed. The white color, the brightness, and the trajectory all matched the behavior of the satellite as it passed over that area.

The full case file is reproduced below as held by the National Archives, comprising 9 pages.