ENQUETE 81 / 01 ANALYSE D'UNE TRACE - NOTE TECHNIQUE N° 16

This technical note (N° 16) from the GEPAN (Groupe d'Etude des Phénomènes Aérospatiaux Non-Identifiés) details the investigation of a UAP sighting and associated physical trace that occurred on January 8, 1981, in the commune of Al, France. The witness, a construction worker referred to as Monsieur C, reported observing a dark, ovoid object, resembling two inverted bowls, descend and land on a terrace on his property. The object, which he estimated to be approximately 1.5 meters high and 2.5 meters in diameter, hovered briefly before taking off vertically at high speed. The witness reported a light whistling sound but no other mechanical noise, heat, or vibration. The GEPAN investigation, conducted in February 1981, focused on the physical traces left on the ground and the biochemical analysis of local vegetation. The trace consisted of two concentric circles with a 10cm thick crust, showing signs of mechanical pressure and thermal modification. Laboratory analyses of soil and vegetation samples revealed the presence of zinc, phosphate, and carbon black, suggesting a potential residue from a coating or paint. Biochemical analysis of the vegetation (Medicago minima) showed significant pigment degradation, particularly in chlorophyll and carotenoids, which the GEPAN compared to effects observed in controlled irradiation experiments, though they noted that the specific mechanism remained unclear. The report concludes that while the physical evidence confirms an event of significant magnitude occurred at the site, the data remains insufficient to provide a definitive explanation for the phenomenon itself. The GEPAN highlights the importance of rapid, systematic data collection in such cases and notes that the witness's testimony, while consistent, cannot be independently verified, leaving the investigation as a valuable but inconclusive case study.