Sighting in Liévin, May 15, 2016

Between 10:30 and 11:00 pm, several people in a garden watched a number of yellow-orange glowing balls drift slowly across the night sky. All of them moved in the same direction, from east to west, and stayed evenly spaced. No sound was heard at any point during the observation. A video and photos were taken, and the witnesses later reported what they had seen to the gendarmerie.

GEIPAN did not receive the photos or the video. The accounts of the 4 witnesses agree with one another and fit a release of Thai lanterns very well: the colors, the shapes, the type of trajectory, and the way the objects vanished, since a lantern going out can look like a sudden, flash-like departure into the distance. The fact that it happened on a weekend night, when celebrations are common, supports this explanation. Wind was not measured at the site; 20 km away it was light (5 km/h) and variable in direction. The lanterns could have traveled about 100 m per minute. They actually fly quite low, at 100 to 200 m, much lower than the witnesses imagined, as people cannot judge the distance of a phenomenon they do not recognize. Over 5 or 10 minutes, even in a light wind, the apparent movement across the sky can therefore be very large.

GEIPAN classified the case as B (probably identified): Thai lanterns.