Above in false colors:
The Richat Structure, a prominent circular feature in the Sahara
desert of Mauritania near Ouadane, has attracted attention since
the earliest space missions because it forms a conspicuous
bulls-eye in the otherwise rather featureless expanse of the
desert.
Described by some as looking like an outsized ammonite in the
desert, the structure, which has a diameter of almost 50 kilometers
(30 miles), has become a landmark for shuttle crews. Initially
interpreted as a meteorite impact structure because of its high
degree of circularity, it is now thought to be merely a symmetrical
uplift (circular anticline) that has been laid bare by erosion.
Paleozoic quartzites form the resistant beds outlining the
structure.
Note: Not a meteor impact site, not a hurricane, not a volcano.
