Sighting in Châtillon-sur-Chalaronne, October 2, 2007

Around 1 p.m., a witness who was in their garden noticed a large, multicoloured diamond-shaped object moving silently at low altitude. Intrigued, they followed it by car for five to six kilometres, between two neighbouring towns, taking photographs during the chase. In the car park of a horticultural business, they met four other people who were just as puzzled by the phenomenon. The witness then drove on but eventually lost sight of the object. An appeal for witnesses published in the local daily newspaper brought a response from many people.

The investigation reconstructed a trajectory consistent with the observations: the object travelled from south-south-west to north-north-east, very close to the direction of the south wind recorded at Lyon. Its average speed, about 20 km/h, was slightly below the wind speed of 22 km/h. These findings pointed clearly towards a lighter-than-air balloon carried by the wind. The appearance described resembled a cluster of small mylar party balloons filled with helium, which may have escaped from its owner or been put together to carry a small payload. It could have travelled a long way before being seen, so its origin is hard to estimate.

The case, with several witnesses and photographs, is very consistent but not very strange, since the object's movement matches the direction and speed of the wind. GEIPAN classified it B: probable observation of helium-filled party balloons.