AUTHON-DU-PERCHE (28) 10.03.1980

GEIPAN continues to publish all its archives on www.geipan.fr. Older cases originally classified A, B, C or D are being reexamined to improve their conclusions. New technical tools (software) and investigative experience gained over the years sometimes lead to new observations or a change of classification. This previously D-classified case, formerly named NOGENT-LE-ROTROU (28) 1980, is among those recently reexamined (see the investigation report). On 10 March 1980 around 21:30, gendarmes listening to another brigade's radio frequency heard that a motorist on the D13 between Les Etilleux (28) and Nogent-le-Rotrou (28) had seen a UAP. Several gendarmes looked in the reported direction but saw nothing. At 22:10, a gendarme, T1, was closing his bedroom shutters at the Authon-du-Perche (28) barracks when he and his wife saw a luminous ball in the clear sky toward Les Etilleux. He called his commanding officer, T2, and the other gendarmes. They watched the ball- or disc-shaped UAP change from bright orange to red and move in successive jumps and stops until it disappeared. The official report gives no exact disappearance time. At 22:40, 4 gendarmes—T3, T1, T4 and T5—set off by car toward Les Etilleux on the D9, then toward Coudray-au-Perche (28), before returning to Authon-du-Perche. The official report says they noticed a dark-red luminous mass during the journey. Stopped at “Moulin Neuf” in Coudray-au-Perche, they again saw a phenomenon described as a stationary, silent, luminous oval at low altitude. The report describes 2 parts using the awkward terms “first lower third”, with dazzling lights, and “second upper third”, with predominantly red-orange lights and red points along one horizontal line. A glow formed a halo around it. No further accounts were collected in the places they visited. The available evidence comprises a preliminary gendarmerie investigation report, without separate statements from each of the 5 witnesses, and a private report published on 10 December 1980 by the Groupe de Recherches Cosmographiques (GRC, Cosmographic Research Group) in Le Mans. The attached GRC report includes transcripts of recorded individual accounts and drawings of the UAPs. GEIPAN did not control the private investigation's interviewing conditions. It cites that report for information and to illustrate how different collection conditions produce differences between accounts. GEIPAN considers that its conclusions can be established from the official report alone: the private report supplies no decisive confirmation or contradiction. It excludes the initial motorist's approximately 21:30 sighting on the D13, also called CD13 in the source, because it was relayed by radio without sufficient detail. GEIPAN considers the case complex because 5 gendarmes probably observed several distinct phenomena that they did not recognize or could not identify. It is difficult to assess because the evidential support is poor: - The official report is the principal evidence in the absence of further interviews conducted directly by GEIPAN. It contains little information and combines accounts without identifying which witness supplied each detail, preventing comparison of agreements and differences. - Some information in the private GRC report is confused or contradictory, particularly the exchanges with the investigator, and does not improve that assessment. GEIPAN distinguishes 3 fairly well-delimited phases involving separate phenomena. Phase 1: observation from the gendarmerie barracks. GEIPAN identifies Venus as the explanation. It considers the planet visible that evening because the witnesses reported stars in the viewing direction. Venus was setting low on the horizon, under conditions conducive to misidentification. The analysis invokes atmospheric turbulence and a group autokinetic effect during naked-eye viewing—apparent movement of a stationary light—as well as T2's astigmatism, optical aberrations in the binoculars and poor focusing during binocular observation. For this phase, the official report's limited description is “a luminous ball ten times larger than the stars appearing in the sky free of cloud masses”. GEIPAN considers that this establishes the general appearance and visibility of stars in that direction. The witnesses did not separately mention Venus, although the analysis finds that it should have been readily distinguishable. GEIPAN regards these details as sufficient to support a Venus misidentification. The private investigation, conducted under conditions unknown to GEIPAN, provides nothing that strengthens or rules out the hypothesis. Phase 1 conclusion: A, very probable observation of Venus. Phase 2: observation during part of the car journey. This involved 3 red-orange points of light. Both the official report and the private report contain very little information about this intermediate phase. Basic data are missing, notably viewing azimuths and elevations, the lights' angular sizes and their angular separation. Phase 2 conclusion: C, insufficient reliable data. Phase 3: observation while stopped on the return journey to the barracks. Four witnesses saw a UAP but described it differently. GEIPAN could not assess this phase because the official report lacks usable individual data. Its presentation suggests that everyone saw and described exactly the same thing, but one gendarme had combined all the accounts. GEIPAN therefore cannot judge their agreement or disagreement, whereas its method seeks each witness's individual statement. This aggregation weakens the evidential support. Confused information and contradictions between witnesses in the private GRC report reinforce that assessment. Phase 3 conclusion: C, insufficient reliable data.