The Richat Structure, also known as the Eye of the Sahara or Guelb er Richat, is a prominent circular feature located in the Sahara desert, in Mauritania.
Due to its remote location, the 50 km wide structure did not receive a lot of attention until some astronauts reported it. Originally thought to have been caused by a large impact from an extraterrestrial object, further study revealed it is likely to be a remnant of when the super Pangea ripped apart, forming what is now Africa and South America.
According to a recent study from Canadian scientists, molten rock pushed up toward the surface created a dome of rock layers. A later eruption about 100 million years ago collapsed the dome which since then eroded to create the bulls-eye that now breaks the otherwise monotonous desert landscape.
The image was taken by Sentinel 2 (Copernicus program) in October 2017.