Bright triangle over Blois in 1965

Summary

On the afternoon of July 23, 1965, several witnesses in Blois spotted a stationary, metallic-looking triangular object reflecting intense sunlight. The testimony, collected years later, was classified as a B case by GEIPAN, which pointed to a stratospheric balloon as the most likely explanation. Such balloons, flying at very high altitudes, can reflect sunlight even after sunset, accounting for both the brightness and apparent immobility. The calculated altitude was consistent with this type of device. Notably, Venus was visible that evening but went unmentioned by the witnesses, perhaps because it sat lower and further west than the object. While this omission adds an interesting nuance, it does not undermine the sounding-balloon hypothesis.