Image taken 1/11/2001: The so-called Richat Structure is a geological formation in the Maur Adrar Desert in the African country of Mauritania. Although it resembles an impact crater, the Richat Structure formed when a volcanic dome hardened and gradually eroded, exposing the onion-like layers of rock.
The Richat Structure can be found on Landsat 7 WRS Path 203 Row 45, center: 21.68, -11.94.
To learn more about the Landsat satellite go to:
Credit: NASA/GSFC/Landsat 7/USGS