Richat Structure - Our Planet
The Richat Structure, also known as the Eye of the Sahara and Guelb er Richat, is a prominent circular feature in the Sahara desert near Ouadane, west-central Mauritania. This structure is a deeply eroded, slightly elliptical, 40 km in diameter dome. Visible from space, it has been a landmark for astronauts since the earliest missions. It was initially interpreted as an asteroid impact structure because of its high degree of circularity. But today, it is argued to be a highly symmetrical and deeply eroded geologic dome.