Sighting in Chaville, July 13, 2023

At around 4 a.m., from home, the witness noticed highly organized light movements in the sky. They described first a crown made of aligned streaks, which very quickly turned into a swirl of light before taking the shape of a donut. The phenomenon lasted several minutes and ended as a small halo of light. The witness heard no noise. They were the only person to report it, and they provided photos.

In those images the light is white, bluish and diaphanous, and the shapes change (crown, line, donut). This matches the impact spots of single-beam searchlights ("skyrose") on a low cloud layer. Such searchlights usually reach more than 10 km, can be controlled automatically or by hand, and can produce fixed or moving beams in various shapes. The movements stopping in favor of a simple halo may be explained by a pause to adjust the setup, or by the end of the show before switch-off. Weather data from Villacoublay, about 4 km away, show that between 4 and 5 a.m. the first cloud layer lay between 1,800 and 2,300 m with very good visibility, around 43 km: conditions favorable to such spots forming and being seen from far away. Festive displays ahead of 14 July, or equipment tests before that date, may have taken place in the area.

The GEIPAN classified the case as A: very probable observation of impact spots, on the cloud layer, from single-beam searchlights located on the ground.