The Black Spheres of Basel
The account
Great black and red spheres supposedly fought over the sky of the Swiss city, like fleets in combat.
What investigators found
The account is interpreted as a description of atmospheric phenomena at sunrise, told as a religious omen.
The story
In 1566, a broadsheet printed in Basel and signed by Samuel Coccius reported that on several mornings in July and August, residents saw many dark spheres in the sky, along with some red ones, that moved rapidly, seemed to collide and then vanished. Another account describes the sun rising blood red. The woodcut accompanying the text shows the spheres scattered over the city.
Like the Nuremberg sheet, the Basel broadsheet belongs to a collection of 16th-century prints kept in Zurich and was rediscovered by ufology in the 20th century. The text itself treats the episode as a divine sign and a call to repentance. Researchers suggest explanations such as spots in the vision of people who looked at the sun, dust or smoke in the atmosphere and other optical effects of dawn.