THOR (LE) (84) 17.12.2016

On Saturday 17 December 2016 at about 20:45, a witness saw a very bright red-orange light moving silently across the night sky. It disappeared quickly, but he had time to take a photograph. Only one account was collected. GEIPAN considers a sky lantern the probable explanation. The naked-eye description fits a lantern, and a weekend evening is conducive to a festive lantern release. Weak wind recorded by Infoclimat is consistent with the impression of slow movement. GEIPAN suggests that the unusual feature prompting the report was the orange squiggle visible in the photograph. It describes the report as considered rather than impulsive, noting that it was submitted more than a month later. The squiggle is a familiar result of camera movement: the exposure lasted 4 seconds, and the witness moved the camera before it ended. The photograph contains a bright central point recorded while the camera was steady, followed by a movement trail whose brightness varies inversely with the speed of that movement. The faster the lantern's image crosses a sensor pixel, the less light that pixel records. Other points, probably stars, show no comparable trails because they were much fainter. They registered during the stationary part of the exposure but crossed other pixels too quickly to register during the movement. GEIPAN explains the light's absence after the photograph as a coincidence: the lantern had gone out. Because the witness described watching the UAP through the viewfinder, investigators suggest he may then have spent some time examining the completed image before looking back at the sky. The photograph and disappearance may therefore not have been as nearly simultaneous as he thought, although such simultaneity remains possible. GEIPAN classifies the case B: probable sky lantern.