LAMONZIE-SAINT-MARTIN (24) 18.01.2018

On Thursday 18 January 2018 at 18:27, 2 witnesses were intrigued by a rounded shape, an intensely glowing ember-orange colour, moving across the sky and suddenly changing direction. Neither heard any sound during their observations. T1 took a photograph. GEIPAN considers a sky lantern a reasonably probable explanation, based on the rounded shape, bright orange colour and predominantly west-to-east movement, consistent with the recorded wind (see Infoclimat). Lanterns are more often released at weekends, but a celebration such as a birthday can also take place on a Thursday evening. The weather had been rainy but had cleared an hour earlier. T1 observed the UAP move from due west at an elevation of 50° to east at an elevation of 30°. This corresponds to a distance travelled of 250–500 m if its altitude was 100–200 m, typical for a sky lantern. These distances are consistent with the measured wind of about 20 km/h and the reported observation duration of around 1 minute. T1 described an uneven glow with additional glows above or below it. GEIPAN interprets this as indicating that the UAP was relatively close. T1 gave it the angular size of an aircraft, while the observation location was 12 km from an airport. A lantern seen at 100 m has an angular size comparable to the Moon's, with uneven colouring that can change with the viewing angle. T2, for their part, noted only bright orange. The photograph provides no useful indication. The witnesses described a straight trajectory followed by a turn whose extent and direction are difficult to assess. T1 was best placed to judge it because the UAP appears to have passed almost overhead; its heading changed from southeast to east. T2 seems to have perceived a bend towards the south. In either case the location is close to a river, where local changes in wind direction or currents of air are possible. GEIPAN classifies the case B: a probable observation of a sky lantern.