Luminous dance in the Lyon sky

Summary

On August 22, 2014, around 1:30 PM, two witnesses observed several bright white points moving several kilometers in the sky. Although only one testimony was collected, the description of the event suggested a surprising scene. At that time, the weather conditions were favorable: mostly clear skies and very light, unstable wind. In the southwest Lyon region, airplanes usually leave contrails between flight levels 357 and 416, but that day, the aircraft tracked by Flightradar24 were flying below these levels, so they did not produce visible contrails. At least five aircraft were present at high altitude, and their relative positions to the sun generated reflections that created the luminous effect observed.

The GEIPAN classified the case as "A", indicating that the observation is attributable to reflections on commercial aircraft that temporarily reflected sunlight due to their position. Although the phenomenon seemed mysterious, the most plausible explanation points to a combination of weather conditions and flight geometry. This type of case, although unusual, is not uncommon and can be difficult to identify with the naked eye.