Spherical UFO with Black Smoke over Iowa

Summary

A 1955 UFO case describes a round object, the size of a basketball, with black spots and a black smoke trail. Seen for 10 minutes in Colfax, Iowa, the object made no sound and moved in circles and rolls. Although no photos were taken, a civilian witness observed it with binoculars. The official evaluation considered it "possibly a balloon," perhaps carrying a package. The report did not rule out other explanations, but the object was never clearly identified.