A triangle shape in France, France

It is 8 p.m. on November 5, 1990, when CNES security services are swamped with calls from numerous gendarmerie brigades reporting a strange luminous phenomenon that crossed a large part of France around 7 p.m. For more than a week, SEPRA will receive many calls from witnesses asking for explanations about "an immense luminous triangle" crossing the sky. Among the witnesses, J.P. Haigneré, CNES astronaut, will confirm the strangeness of the phenomenon. At the balloon launch center in Aire-sur-Adour, technicians will delay a launch to observe the phenomenon! The SEPRA service is reinforced for the occasion, and the search for information begins with civilian and military aviation authorities, meteorological services, and NASA for a possible atmospheric re-entry. NASA's response arrives on November 8, indicating, for November 5, the re-entry of the object "20925/1990 94C / GORIZONT 21 PLATFORM / USSR". CNES orbitography services confirm the trajectory of this re-entry, which crossed France from the Gulf of Gascony to Alsace. This information is provided to press agencies on November 9, 1990. Note that a witness, a member of a particularly effective observation network, informed SEPRA as early as November 6 that it was the re-entry 90/94C and that it had passed 103 km above the Gulf of Gascony before exiting in eastern France at 83 km altitude. The overflight of a debris cloud from a third stage of a Soviet PROTON rocket occurs at an altitude of 100 to 50 km and at a decreasing speed of 7 to 2 km/s (25,000 to 7,200 km/h). However, any witness cannot estimate the distance of an unknown object, especially luminous points, at night. Yet their brain unconsciously estimates a distance, based on the luminous intensity of the phenomenon. (see the explanation on estimating the size and distance of an unknown phenomenon.) This cluster of molten debris, followed by trails, stretches across space over several tens of kilometers depending on the shape and composition of the metal pieces. And it is the luminous power of the phenomenon that made it appear close to witnesses. This illusion of proximity is observed with every bolide observation. This perception illusion, called distance illusion, is well known to visual perception psychologists. Just like the contour illusion or shape illusion: in this case, when an observer sees a set of points moving together, their brain constructs a virtual object carrying these points. See the article on the psychology of form. However, the majority of testimonies of the atmospheric re-entry of November 5, 1990, report the observation of a dark craft, equipped with multiple lights, flying at low altitude, from WSW to ENE. The testimonies are consistent with the observation of a cloud of molten debris from the fragmentation of the third stage of a PROTON rocket re-entering the atmosphere: -the observation time and its duration, -the multiple luminous points, -the observation direction: see the new simulation of the atmospheric re-entry of 05.11.1990, -the apparent size (some witnesses are surprised to see that the apparent size does not vary during the passage: proof that the object is very distant). GEIPAN classifies this case "A" as an observation of the atmospheric re-entry of the third stage of a PROTON rocket. Several witnesses, very shocked by their observation, did not accept this explanation.