An account in Gironde, France

On October 26, 2017, two witnesses on the beach at La Chambrette in the commune of Le Verdon-sur-Mer (33) are intrigued by white filaments falling from a clear sky. One witness picks up a few filaments to examine them. It is then that the two witnesses see the rapid and silent passage of two shiny discs moving side by side in the sky. The filaments continue to fall for a few minutes, then everything returns to normal. The witness manages to catch one filament. The witnesses describe two simultaneous phenomena: 1. filaments 2. discs, whose speed, shape, and color do not match known devices. The spider ballooning hypothesis accounts for most of the characteristics described by the witness. Silk threads (also called "gossamer") are threads created by spiders to move through the air and by the wind. This means of locomotion is called "ballooning." The threads can be rolled into a ball, which can give the dual appearance of threads and discs seen from the ground. Two arguments could seemingly have opposed this hypothesis: 1. The wind coming from the south or west according to weather records. But the witness describes locally "a southeast breeze" consistent with the direction of movement and therefore with the hypothesis. 2. The distance estimated by T1 and T2 (5000 m for T2, 10000 m for T1), but it is known that estimating the distance of an unknown object is difficult to use, absent a frame of reference. The testimony is consistent, the witnesses credible with concordant observations. After a first publication in March 2018, the witness gave us a sample of a filament recovered during the observation in mid-September (see section 3 of this investigation report). It was analyzed by a CNES laboratory. This analysis confirms that it is indeed silk fibers mixed with particles, mostly iron oxide (see appendix of the report). This case had previously been classified B; this new element, which constitutes near-proof of the hypothesis, allows us to classify it A and republish it: observation of spider ballooning.