Stunning Space Views: Sahara's Meteor 'Eye' and Earth's Impact Craters

The Aorounga structure in the Sahara Desert, Chad, is an 8-mile-wide impact crater formed by a "city-killer" asteroid around 345 million years ago. Captured in a 2013 photo by an astronaut aboard the ISS, the crater's eye-like appearance is due to its two rings, with migrating sand dunes surrounding it. These dunes, known as barchan dunes, move significantly over time, as tracked by satellite images. The crater may be part of a "crater chain," with smaller craters nearby suggesting fragments of the original meteor impacted the area.