Sighting in Chatou, July 7, 2018

On a Saturday night at 11:39 pm, a witness saw and filmed a round, bright, orange object moving silently across the night sky. It flashed several times and then vanished behind a cloud. The witness considered several explanations but remained puzzled. Only one account was collected.

The GEIPAN investigation concluded that the witness had mistaken a Thai lantern, carried by the wind and probably released during a celebration. The round shape matched the lit centre of the lantern, and the yellow-orange colour with a lighter halo around the edge matched its casing lit by the flame. The silent movement and the short observation, about two minutes, were consistent, since a lantern can stay lit for more than ten minutes. The disappearance, visible on the video, corresponded to the flame going out: near the end of its fuel, a lantern's flame flickers and weakens, and the witness themselves noted three flashes before it vanished. A summer Saturday evening is also a likely time for festivities and lantern releases.

The witness had greatly overestimated the distance. The IPACO software applied to the photograph and the angular data given by the witness produced the same result, about 150 to 200 m. Both puzzling features were explained: the absence of wind they felt was due to being sheltered on their terrace, and the speed they judged too high was only a subjective impression caused by believing the object was much farther away. The curved path was only apparent: the initial vertical climb was taken for movement toward them, and the lantern then gradually turned southward in a stronger air current. The case was classified A.