These twin impact craters are Clearwater East and West craters located in Quebec, Canada. They were formed at the same time by two separate but probably related meteorite impacts. This rarely occurs on Earth. The larger Clearwater Lake West (left) shows a ring of islands that has a diameter of about 10 kilometers (6 miles). They constitute a raised area and are covered with impact melts. The central peak of the smaller Clearwater Lake East (right) is submerged. (Courtesy NASA/LPI)