An account in Haute-Savoie, France

On January 21, 2015 at around 6 p.m., three people observe through the living room window and then from the terrace a phenomenon they cannot explain. At first, from inside, the phenomenon seen is shaped like a water drop and yellow in color, moving across the sky. The witnesses go out onto the terrace and then see the UAP in a circular shape and matte black, which disappears quickly. The observations are made with the naked eye and with binoculars. Only one questionnaire was received, but an on-site investigation made it possible to refine or correct certain data (see the investigation report). What made the observation strange was the juxtaposition of two sequences that at first glance could not be linked to the same phenomenon. Following the investigators' trip to the site and based on the descriptions given by the witnesses, it appears that a (short) condensation trail from an aircraft is likely. The three witnesses observed the phenomenon intermittently at nightfall. At first, the sun's rays lit up the trail; in the second phase of the observation, the sun's rays could no longer directly illuminate the area of sky crossed by the aircraft. An aircraft trail can thus quickly change from a bright spot to a dark spot. Consequently, GEIPAN classifies the case as B: probable observation of an aircraft condensation trail.