Sighting in Lyon, July 28, 2016

Shortly after one in the morning, between 1:10 and 1:14, a witness opened their window and for a few seconds saw several points of light forming a kind of "V" and moving quickly. They first thought of birds lit from below, then of fighter jets, but heard no noise. The white-yellow points faded away into the night. Only one account was collected.

GEIPAN concluded that this was probably a flight of Thai lanterns. The lights looked like stars, except that their apparent size changed: it decreased, probably because the lanterns were moving away. The formation flight is explained by lanterns carried along in the same stream of wind. The upward pitch and final disappearance fit the fact that lanterns often go out at the same moment, which can alter their trajectory.

The wind recorded in Lyon that night came from the west. The observed movement was toward the east, consistent with the wind, and also toward the north, since the points were moving away from the witness, who was looking north, as shown by the drop in angular size and in height above the horizon. The sighting took place in the city, very close to a large river, a setting that favors local variations in wind compared with a weather station's readings, even one only a few kilometers away. Finally, a summer night lends itself to festive lantern releases. The case was therefore classified B: probable observation of Thai lanterns.