SIORAC-EN-PERIGORD (24) 17.08.2014

On 17 August 2014, a witness in Siorac-en-Périgord saw a straight luminous streak, then several others moving across the sky near the horizon at sunset. He filmed and photographed them. GEIPAN explains that this appearance is characteristic of aircraft contrails. The day's excellent visibility allowed aircraft to be seen farther away than usual. Distance makes their trails appear shorter and slower, and they can appear more or less vertical when an aircraft is approaching or receding. A trail's appearance or disappearance may depend on weather conditions at the aircraft's location. GEIPAN considers the photographs conclusive and notes that the witness was looking toward an area with very heavy air traffic, particularly on a summer Sunday evening. It classifies the case as A: airliner contrails.