Sighting in Annecy-le-Vieux, October 20, 2002

At around 6:40 pm on a Sunday evening, a couple standing on a terrace noticed a group of 7 to 9 very small dark or black objects moving silently across the sky. The objects moved in relation to one another, rotating, drifting apart and coming closer together. One identical object stayed separate from the group. The witnesses watched first with the naked eye, then through binoculars, for about ten minutes. The whole group travelled toward the NNE, very slowly and at a constant altitude. Only one account was collected, even though several people were present. Air traffic control for the area was contacted and had reported no particular activity. No photo or video was taken.

The case, originally classified D, was re-examined. Two explanations were considered. A flock of black birds on migration was plausible given the location and time of year, but it fitted poorly with the calculated altitude, duration and speed, and above all with the direction of travel, which was opposite to that of migration. The second, a cluster of black balloons tied together with strings, matched the data well. A light south-westerly wind was blowing in the same direction as the objects' movement. With an estimated altitude of 500 m, the total angular displacement of about 67° was plausible. Held by loosely slack strings, the balloons would drift as one body while moving randomly relative to each other. GEIPAN did not have enough experience with this kind of balloon release at the time. The case remains weakly consistent, notably because angular data are missing. GEIPAN classified it B: probable observation of recreational balloons.