Sighting in Rentree Atmospherique 5 Novembre, November 5, 1990

At around 7 p.m., a luminous phenomenon crossed a large part of France. By 8 p.m., CNES security services were flooded with calls from many gendarmerie units reporting it. For more than a week, SEPRA received numerous calls from witnesses who described an immense luminous triangle crossing the sky. One of them, a CNES astronaut, confirmed how strange it looked, and at the balloon launch center at Aire-sur-Adour, technicians delayed a launch to watch it. Most accounts described a dark craft with many lights, flying low from west-southwest to east-northeast.

SEPRA, reinforced for the occasion, questioned civil and military aviation authorities, weather services and NASA. On 8 November NASA reported that a Soviet object designated 1990-94C (Gorizont 21 platform) had reentered on 5 November. CNES orbit-tracking services confirmed a path from the Bay of Biscay to Alsace, and the information was given to the press on 9 November. A witness belonging to an observation network had already identified the reentry on 6 November: the object passed 103 km above the Bay of Biscay and left over eastern France at 83 km altitude.

The investigation concluded that this was the reentry of the third stage of a Soviet Proton rocket. It was a cloud of molten debris at 100 to 50 km altitude, slowing from 7 to 2 km/s and stretched over several tens of kilometers. Its brightness made it look close, a distance illusion common with fireballs, and the brain also merges moving points of light into a single object. Timing, duration, multiple lights, direction and constant apparent size all matched. The case was classified A. Several witnesses, deeply affected by what they saw, did not accept this explanation.