MONTLUEL (01) 14.05.2022

On 14 May 2022 at about 03:10, a single witness observed a UAP from his apartment balcony in Montluel (Ain, 01). Looking south, he watched an anthracite-gray rectangular object travel from west to east for about 8 seconds. It had no lights or trail and, according to him, appeared about 20 × 40 mm in size at arm's length. It emerged silently from behind a hill to the southwest at an elevation of 15°, followed a straight horizontal path, then disappeared behind another hill to the southeast at the same elevation. He described two striking features: distortion of the clouds as it passed, which he compared with effects around black holes, and a faint white halo surrounding it. He found the observation particularly strange. The case's evidential strength*, initially assessed as moderate, was reassessed as good after the field investigation. This reflected the witness's excellent cooperation, despite the lack of photographs or video of the UAP and the one-off nature of the sighting. The witness completed the technical questionnaire only 3 days after the observation. The information collected during the field investigation 13 months later was very comprehensive and appeared reliable (see the investigation report). *Under GEIPAN's criteria, evidential strength is the amount of information collected for an account that is considered reliable and objectively substantiated. Field measurements and analytical calculations, allowing for the witness's overestimate of the UAP's apparent size, showed that, if it disappeared behind a hill at the end of the sighting as reported, it must have been at least 15 meters long and traveling at least 130 km/h. The witness himself considered several explanations: a natural phenomenon resembling a moving rectangular black hole, a military aircraft with concealment capabilities, a heat-emitting airship, a swarm of insects, a low cloud or a possible mental projection. However, none satisfactorily explains the reported features, owing to substantial differences between those possibilities and the described phenomenon. An aircraft also appears unlikely, although the calculated viewing distance and possible sizes and speeds are compatible with an aircraft. This low likelihood reflects the marked difference between the UAP's appearance and that of an airplane or drone. Moreover, no aircraft was recorded on radar or appeared on the reconstructed-track maps from CAPCODA, the French Air and Space Force's Air Operations and Air Defense Planning and Control Center. The investigator proposed two further explanations: - A waking dream, hypnopompic or hypnagogic. Although several causes are possible, the investigation focuses on insomnia or fragmented sleep in connection with the witness's nighttime activity. He said that between December 2021 and December 2022 he had followed a shifted schedule, going to bed around 06:00, adapting quickly and never drifting off during his waking nighttime hours. Given this, the investigation considers it unlikely that he experienced this type of waking dream on just this one occasion. - A negative retinal afterimage. Prolonged exposure to a light source can produce a persistent negative image on the retina. Because the witness spent much of the night at his screens, facing rectangular windows, he might have experienced this during breaks. A sudden transition from bright light to darker surroundings could theoretically produce a dark rectangular optical illusion resembling the reported UAP. The chronology reconstructed during the field investigation indicates that about 30 seconds elapsed between leaving his workstation and the observation. The possible persistence of such an illusion remains uncertain, however, because it requires prolonged concentration and a fixed gaze, and is favored by keeping the eyes closed. The investigation presents several strong objections: - Repeated observing conditions: the witness had worked under the same conditions for several months and followed the same break routine. The investigators considered a single occurrence without his previously being struck by it improbable. - No observation in darkness: if a retinal afterimage were responsible, he should also have seen it while walking through the dark to the balcony, which he did not. - An unexplained feature: the distortion of background clouds during the UAP's passage, central to its perceived strangeness, was judged not explicable by a simple optical illusion. These considerations led the investigation to conclude that a retinal afterimage did not match the reported phenomenon. As no known-phenomenon hypothesis reduced the strangeness perceived by the witness, and the account's evidential strength was considered satisfactory, GEIPAN classifies the case D: phenomenon unidentified after investigation.