Sighting in Saint-Priest-la-Plaine, September 15, 2024

At around 8:42 pm, a driver travelling on the N145 noticed, through the window of the vehicle, a grey dot that seemed to hang motionless in the sky above a tree. Intrigued, they took a photo of it. After a few minutes, the object suddenly vanished. On 10 December 2024, the witness sent GEIPAN a technical questionnaire along with the photo. With a single witness but a photograph available, the case was rated as having medium consistency.

The investigation showed that the object was a gas balloon from team LTU-1, which was taking part in the 67th Gordon Bennett Cup. In this race, 24 balloons had left Germany heading for southern Portugal, crossing part of France on the way. The photo made it possible to pinpoint where the witness was and the direction of the sighting. The real-time tracking website for the balloons confirmed that the LTU-1 balloon was in that direction at that moment. This type of balloon is rounder than a hot-air balloon and can look as if it has no basket when seen from far away.

The apparent immobility was explained as an optical effect caused by the distance and by the witness's own movement in the vehicle, while the balloon was travelling at about 46 km/h. Since the observation was made against the light, the sudden disappearance was explained by a change in the witness's position relative to the balloon, which altered the lighting and made it invisible. GEIPAN classified the case as A: observation of a gas balloon from the 2024 Gordon Bennett Cup.