FONTAINE (38) 27.12.2016

On December 27, 2016 at midnight, the only witness to this observation case is in the bedroom of his apartment, on the 4th floor of a residential building in Fontaine (38). He observes, to the northeast about 75° of elevation, a UAP of round shape "like a star", of orange colour and a brightness comparable to that of a celestial object. This UAP moves silently, at moderate speed, on a path generally oriented east/north, before being lost from view to the northeast at an elevation of about 60°, after 1 minute 30 seconds of observation. The witness insists on the absence of noise, on the orange colour of the light source and on a trajectory that appears to him "almost at right angle", these elements constituting the bulk of the perceived strangeness. The evidential quality* of this case remains medium, due to there being only 1 witness and the absence of a photo or video of the phenomenon. The strangeness of this case is essentially based, for the witness, on the orange colour of the UAP - since he thinks first of a gendarmerie or civil-protection helicopter, but notes the absence of red and green flashing diodes - as well as on its trajectory "nearly at right angle". The hypothesis explored, that of observing a sky lantern, is supported by the following: - Spherical shape and orange colour, typical of a lantern; - Silent and moderate speed travel, compatible with the drift of a lantern carried by weak local air currents; - Short observation time, consistent with the usual visibility time of this type of object. The analysis of the wind does not contradict this hypothesis, because the weather elements available suggest not a strong and homogeneous wind, but rather a situation of weak and locally variable winds at the scale of the Grenoble urban area. In a basin surrounded by varied terrain such as Fontaine (38), such winds can result in weak local air currents, sometimes different between the ground level, the areas near buildings and the slightly higher layers at altitude. Therefore, the lack of wind felt by the witness at his observation point does not preclude the presence of a sufficient flow of air to ensure the slow drift of a passive object carried by the wind. Moreover, the description of a "right to left" or "turn" does not in itself allow for the determination of an absolute direction of the phenomenon in a nighttime sky without clear reference points. Thus, the impression of a trajectory "nearly at right angles" can be explained either by a slight variation in the local airflow encountered as the lantern rose, or by a simple perspective effect affecting the perception of its displacement. The whole therefore remains compatible with the expected behavior of a sky lantern observed at night. The sky lantern hypothesis (form, colour, trajectory, silence) reduces the strangeness perceived by the witness, although GEIPAN found no evidence of a release at the time of the sighting. GEIPAN classifies in this case as "B": likely observation of a sky lantern. *EVIDENTIAL QUALITY: Under GEIPAN’s criteria, this is the amount of information collected for an account that is considered reliable and objectively established.