[RN1] de SAINT-DENIS (974) vers POSSESSION (LA) (974) 11.12.2016

On Sunday 11 December 2016 at about 18:30–18:45, a woman driving saw an orange-red phenomenon in an otherwise clear sky, shaped like 2 trails topped by a sort of rectangle. It appeared stationary, then rose and slowly faded until it vanished completely. The sighting lasted 3–5 minutes. Only 1 account was collected. GEIPAN considers her initial impression probably correct: ‘I think it is an atmospheric phenomenon, but I do not know enough to check.’ The likely explanation is clouds illuminated by the setting Sun. In the reported direction, west or southwest of her position, the Sun was setting at 18:45 at azimuth 250° and may previously have gone unnoticed while she was driving. Although she described a clear sky, small wisps of cloud can strongly reflect sunset light, forming unusual orange geometric patterns, here trails topped by a rectangle, before fading. Venus and Mercury were bright in the reported direction, particularly Venus at magnitude −4.2 and elevation 35°. Either she failed to notice Venus, which can happen, or cloud hid it. GEIPAN states that in either case the phenomenon was not seen at the reported elevation of 40°. It notes that errors in estimating elevation without a local geographical reference are very common. GEIPAN consequently classifies the case B: observation of clouds.