LaGrand, IowaSeptember 1955

In early September 1955, two ground observers using binoculars reported seeing unusual lights in the sky near LaGrand, Iowa. One observer, a farmer with three years of experience with the Ground Observer Corps, watched red and green flashing lights in the northeast, east, and southwest sections of the sky for two hours and fifteen minutes starting around 2330 hours (11:30 p.m.). A second observer, a service station attendant, saw a similar light in the northeast with a steady green glow and flashing red light. The objects appeared to move slowly across the sky, though one seemed to remain stationary. Both observers described the lights as about the size of a pinhead held at arm's length.

The Air Force's Flight 2-A investigation unit from the 4602D Air Intelligence Service Squadron looked into the sighting carefully. They checked with research agencies throughout the Minneapolis area and confirmed that no balloons had been deployed over Iowa at the time. They also noted that weather balloons carry only red flashing lights, not green ones. The University of Minnesota observatory reported nothing unusual in their records for that night.

The investigating officer concluded that the sighting was most likely caused by stars or planets. Continued observation of bright morning stars or planets, he reasoned, could create the optical effect of red and green flashing lights, especially when viewed through binoculars. The apparent lack of motion could be explained by Earth's rotation. Because the same lights had been observed on five successive nights, and because no balloons or other aerial activity matched the description, the officer favored an astronomical explanation.

The full case file is reproduced below as held by the National Archives, 22 pages total.