Sighting in Fleury-Mérogis, October 20, 2011

At about 9:10 pm, an amateur astronomer was watching the sky when they noticed a particularly bright white point of light. It moved slowly from west to east, rose toward the vault of the sky, then vanished suddenly after a few seconds. The witness put its maximum elevation at 60 to 70°.

GEIPAN's investigation found the case to be of low strangeness and the account consistent. The description matches how the ISS looks when it enters the Earth's shadow and disappears. A simulator, however, gave a disappearance time of 9:03 pm, seven minutes before the time of the sighting, and a maximum elevation of about 50°, lower than the witness's estimate. The gap was attributed to the fact that ISS orbital data changed noticeably from one day to the next at that time, probably because of manoeuvres, which makes it very difficult to obtain precise orbital data. The case was classified B: probable sighting of the International Space Station.