Callisto

Callisto

Jupiter’s moon Callisto has one of the most heavily cratered surfaces in our solar system. This ancient terrain preserves a record of intense bombardment early in the moon’s history. Large impact basins often exhibit a few concentric rings. But scientists were amazed when Voyager 1 revealed this “bulls-eye” of countless rings of Callisto’s huge Valhalla Basin. The basin is 2,500 miles (4,000 kilometers) across.