[AERO MIL] BRIOUDE (43) 20.09.1956

On 20 September 1956 at 15:50, two pilots flying on patrol saw a moving, aluminium-coloured spherical object. They climbed in an attempt to approach it but found they could not reach it. They abandoned the pursuit at 16:10. An inquiry to the director of the Puy-de-Dôme observatory at Clermont-Ferrand established that a translucent, approximately spherical balloon with a slight bulge at its base had been observed in the Clermont-Ferrand sky throughout that day. It drifted continuously at very low speed at an altitude of 20 kilometres. At 19:05 it became invisible when sunlight no longer illuminated it. Its origin was unknown: neither the observatory nor regional meteorological services had launched a balloon. GEIPAN classified the case B, attributing the observation to a stratospheric balloon whose origin had not been established. It explained that a distant object can produce the impression of following an observer while remaining difficult to approach. In this case, the very large balloon was about 17 kilometres from the pilots. Their climb to 32,000 feet, approximately 10,000 metres, reduced the distance only to about 10 kilometres.