Berlin, Germany, May 1957May 1957

On May 21, 1957, at 1830 Zulu time (daylight), three military observers at Tempelhof Air Base in Berlin reported seeing objects. The men were Air Force airmen and a special agent, all considered reliable. The sky was clear with no wind.

The objects were circular, about the size of a grapefruit, and silvery. One observer saw three objects, while two others saw two each. Most followed a northeasterly path before fading from view. One object stopped abruptly after crossing about a quarter of the visible horizon in two to three minutes. The objects were visible from about two to ten minutes. Radar scanning, requested right after the sighting, was negative.

The report notes a weather balloon had been launched and tracked earlier, bursting before the sighting. The Air Force record (Project 10073, its official file for unidentified flying object reports) gives a preliminary view that the objects were propaganda balloons sent aloft by information agencies in the area.