SAINT-MICHEL-EN-GREVE (22) 04.08.2024

At 23:23 on 4 August 2024, a witness on a beach at Saint-Michel-en-Grève (22) saw a short bluish trail moving from northwest to southeast across the night sky. He took a 30-second exposure in which the object appeared clearly. GEIPAN assessed the evidential strength as good: although there was only 1 witness, the photograph could be fully analysed. It defines evidential strength as the quantity of reliable, objectively supported information collected for an account. The investigation considered atmospheric entry of a meteor and re-entry of space debris; the short, bluish, straight-moving trail was visually compatible with either. See the investigation report. Measurements and calculations using IPACO, GEIPAN's image-analysis and processing software (IPACO.fr), yielded an estimated velocity of about 3 km/s if the motion was transverse to the witness's line of sight. The source explains velocity as specifying both speed and direction. GEIPAN considered this well below the characteristic speeds of natural atmospheric entry and ruled out that hypothesis. It therefore favoured re-entry of a human-made space object, probably debris burning in the dense layers of the atmosphere. GEIPAN asked CNES's space-surveillance operations centre whether such debris had been detected. According to the source, the filters used only allowed detection and cataloguing of debris with a frictional surface area greater than 10 m² and an estimated mass above 2.5 tonnes, so sufficiently small debris could have gone unrecorded. GEIPAN classified the case B: probable atmospheric re-entry of space debris.