Official record
Two crew members saw it rapidly approaching, then vanishing.
The incident occurred in 1953 near the town of Hässleholm in Sweden.
Captain Olof Christiansson and Ola Johansson reported seeing a metallic object from a DC-3 plane.
The object came from the opposite direction, approximately 600 meters below the plane.
The crew estimated the object was moving at the speed of sound and saw it for six or seven seconds.
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