Sighting in La Motte-Servolex, June 2, 2018

At about 10:05 p.m., a witness at home noticed an orange, circular glow coming from the direction of Chambéry. It moved slowly across a stormy sky. Looking through binoculars, the witness saw not one but three "lights" surrounded by a kind of orange haze. Two other witnesses also saw the phenomenon. The first witness estimated the sighting lasted 40 minutes, a duration the investigation checked and confirmed. For about 4 minutes they also saw four steady blue lights of varying intensity, from moderate to strong. The phenomenon passed silently. The witness also thought they glimpsed, for the length of a flash, a structure beneath the lights.

GEIPAN exchanged emails with the main witness. These brought additional details but did not explain everything, and they raised further odd elements that were more or less incompatible with the hypotheses considered. The investigation looked at a group of Thai lanterns, then at festive light-up balloons with built-in LEDs. The two ideas are close, but the long duration and the steady blue lights favored the balloons, with lanterns kept as a secondary hypothesis. The case closely resembles one seen in Chambéry the next day, at about the same hours and also with a duration that was too long. Balloons or lanterns may have been released on both of these end-of-week evenings. Most of the observation's parameters fit this explanation. GEIPAN classified the case as B, probably identified.