Burlington, IowaApril 1958

In April 1958, approximately 28 people called a radio station in Burlington, Iowa to report a fiery object moving across the sky. The sighting occurred on April 29th at 2107 GMT (9:07 p.m.) and lasted about 10.5 seconds. Witnesses described the object traveling horizontally from north of Burlington, moving in a semi-circular arc toward the southwest before disappearing from sight in the same manner it had appeared.

The Air Force also received reports from the U.S. Coast Guard about what may have been the same object. Coast Guard observers described a bright white light at high altitude, moving from north and making a semi-circular arc toward the southwest. A second report from the same source indicated the object was moving from west to north at a different time. The object's appearance and movements led investigators to note that it did not appear to be an aircraft.

The case file indicates the Air Force evaluation concluded the object was probably a balloon. The original sighting in Burlington was recorded as ground-visual observation with no photographs taken. While the maneuvers and rapid movements initially suggested the possibility of an aircraft, the final determination attributed the sighting to a balloon.

This case file, comprised of 10 pages, is reproduced below as held by the National Archives.