The “Eye of the Sahara”

iss059e013142 (April 5, 2019) --- From an altitude of 255 miles, an Expedition 59 crewmember photographed the Richat Structure, or the "Eye of the Sahara," in northwestern Mauritania. The circular geologic feature is thought to be caused by an uplifted dome—geologists would classify it as a domed anticline—that has been eroded to expose the originally flat rock layers.