An account in Hautes-Alpes, France

On January 20, 2012 at around 8:25 a.m., a witness and her daughter noticed, in the clear sky above the Col de Blaux, the presence of an aerospace phenomenon that intrigued them. The witness took photos of a white smoke whose left end turned black before disappearing behind the mountain on the side of the Vallée du Caire (04). The witness thought of something falling and crashing to the ground but did not see any aircraft or hear any particular noise. She gave testimony to the gendarmerie. The gendarmerie investigation found no trace on the ground, no other testimony was collected from the valley's residents, and no sign of brush burning or fire in the area. The hypothesis of a military aircraft passing through could not be confirmed. The gendarmes noted that at this time of year and in this time slot, the sunrise is low and dazzling, which could explain in particular the color change of the smoke. This observation was the subject of several press or internet articles. In view of the investigation elements, three hypotheses were considered: fall of an aircraft, smoke coming from the ground, aircraft condensation trail (see the investigation report). GEIPAN classifies this case "B": very likely observation of a persistent aircraft condensation trail that was deformed by wind shears to which it was subjected since its creation. The gray part is indeed a part not yet illuminated (sunrise).