Sighting in Challes-les-Eaux (73) 11.10.2017 T1, October 11, 2017

At about 2:30 pm, the witness was lying on a deck chair, looking at the sky to the south. They suddenly noticed a white, fairly round object, about the apparent size of a handball, moving quickly eastward. After roughly a minute of observation, the object seemed to go "backwards". The witness went to fetch their mobile phone to photograph it. On returning, they had trouble finding it again, but eventually managed to take a picture: the image showed only a bright white blotch. They then searched the sky again through the phone and found a smaller object, which soon disappeared from view.

Back in the deck chair, the witness then saw filaments floating in the air. Their daughter, who was present, noticed them too. The witness took several photos and later found some of these threads caught in their cherry tree.

Only one account was collected. It was judged consistent, the witness being precise and giving the investigator everything needed for a proper analysis; the photos were a valuable addition. The analyses identified two separate phenomena. First, two aircraft were crossing at the same time and in the same part of the sky, which created the illusion of a single object reversing. Second, the photographed threads were "gossamer" ("fils de la Vierge"): silk threads that carry tiny young spiders along on the wind, a phenomenon called ballooning. GEIPAN classified both cases as A: a misidentification of airliners for the first, and an observation of ballooning for the second.