Although it is only 25 miles (40 km) across, Aristarchus can easily be seen, as it is at the center of a ray system. It is also one of the brightest craters on the Moon, which facilitates the observation. It is only 450 million years old and one of the younger large craters. Its walls rise 3281 yards (3000 m) above the crater floor, the central peak is 547 yards (500 m) high.