Sighting in Liancourt, April 18, 2015

On a Saturday night, around 11:45 pm, a witness was on their property when they noticed two luminous objects, one white and one red, moving about in the night sky. They seemed to fly one behind the other. No particular noise was heard. The sighting ended at 11:53 pm, and the witness reported it to the gendarmerie by letter.

According to the account, the objects stopped above the marsh. One then rose and headed west, while the second left the witness's field of view at very high speed toward the north. That second object was said to have come back afterward.

The investigation established that there had been no unusual weather that evening, that no local councils had held fireworks displays in the area, and that no military training flights had taken place. A check in the neighbourhood turned up no other witnesses. GEIPAN compared these white and red lights, which crossed the sky within a few minutes on a weekend night, to Thai lanterns, probably released nearby after a private party. Their path from the north-west toward the west matches the north-east wind of 20 to 30 km/h recorded at Creil. Stopping above the marsh remains possible if the wind weakened or shifted there, given the relief of the valley. The upward departure could come from a lantern gradually going out, which witnesses often read as moving away. The fast departure toward the north, against the wind, fits a wind-borne object only if it was also a perceptual illusion as the lantern went out; the return could then be a third lantern released from the same spot. The case was classified B: probable Thai lanterns.