Duluth Minnesota, March 1959March 1959

On March 13 and 14, 1959, military pilots and ground radar operators near Duluth, Minnesota reported seeing an unidentified flying object in the western sky. The object was described as round or tubular in shape, with rotating red and green lights. Multiple witnesses, including crews from two B-52 bombers and two F-102 interceptor aircraft, reported visual sightings. Ground-based radar also picked up contacts, though the radar returns were inconsistent, with some operators reporting sharp blips and others reporting fuzzy or fading signals.

Two F-102 interceptors were scrambled to investigate and attempted to close on the object at high speed without success. The object appeared to maintain a constant bearing of approximately 300 degrees (roughly northwest) and disappeared after roughly thirty minutes by fading from sight. Weather conditions were clear with good visibility. The radar film from ground stations was forwarded to the Air Technical Intelligence Center (ATIC) for analysis.

After investigation, the Air Force concluded that the radar returns were most likely due to interference from the aurora borealis (northern lights), not an actual physical target. The visual sightings were attributed to the planet Venus, which was positioned near the western horizon at the time. Atmospheric refraction and layers of air at different temperatures could have distorted Venus's appearance, producing the apparent changes in color, shape, and motion reported by the witnesses. The fact that the object maintained a constant relative position and that the F-102s could not close on it supported the Venus identification.

The full case file is reproduced below as held by the National Archives, with 318 scanned pages.