Sighting in Roissy-en-France, April 18, 2016

At around 5:40 pm, two witnesses waiting at a bus stop saw an object pass across the sky, twinkling and spinning on itself. Both described it as square. The first witness judged its path to be a straight line, while the second found it to be descending. The first witness filmed the scene and put the observation at about two minutes; the second estimated thirteen minutes. Both thought it might be debris fallen from an aircraft. No other testimony was collected.

The witnesses had in fact observed two objects. Their accounts are numerous and detailed, but of limited reliability: they themselves reported poor viewing conditions, with the sun making it hard to make out the object, which showed itself only through occasional flashes of white light. This may also explain the discrepancies and contradictions in the trajectories described. The analysis relied mainly on the video of the second object, since nothing in the statements ruled out the first having the same explanation.

The GEIPAN considered the case to have low strangeness, mostly because of the object's regular rotation around its transverse axis. Its physical characteristics and motion resemble those of light debris subject to gravity and to a rotation of unknown initial cause, or one produced by wind and local turbulence in an urban setting, combined with a favorable shape. The descent itself creates a relative wind that can sustain the rotation, since the witness's drawing shows a horizontal axis. That rotation, with lift and drag, could account for a 20 to 40° deviation from the wind direction. The case was classified B: probable observation of a light piece of debris of unknown origin.