Dark objects over Annecy-le-Vieux explained as balloons

Summary

In October 2002, a couple in Annecy-le-Vieux watched seven to nine dark objects drift slowly north-eastward at a constant altitude for about ten minutes. Air authorities recorded no notable activity in the area. GEIPAN investigators considered two hypotheses: a flock of black birds and a cluster of tethered balloons. The bird theory did not fit well, particularly because of the unusual direction of movement. The balloon hypothesis, however, better matched the observations — the wind was blowing in the same direction, and the individual movements within the group were consistent with balloons tied together and influenced by local wind.