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.
This image was acquired by
Landsat 7's Enhanced Thematic Mapper plus
(ETM+) sensor on January 11, 2001. This is a false-color composite image made using shortwave
infrared, infrared, and green wavelengths. The image has also been sharpened using the sensor's