Richat Structure
The Richat Structure, also known as the Eye of the Sahara, is a prominent circular feature in the Sahara desert of Mauritania near Ouadane. It has attracted attention since the earliest space missions because it forms a conspicuous bull's-eye in the otherwise rather featureless expanse of desert. The structure, which has a diameter of approximately 50 kilometres (31 mi) and is located 400–450 metres (1,310–1,480 ft) above sea level, has become a landmark for space shuttle crews.
Initially interpreted as a meteorite impact structure because of its high degree of circularity, it is now thought to be a symmetrical uplift (circular anticline or dome) that has been laid bare by erosion. Paleozoic quartzites form the resistant beds outlining the structure. The lack of shock metamorphism at the site further backs the latter claim.
References
- Original entry was from the NASA Earth Observatory http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=9319
Further reading
External links
- NASA Earth Observatory page
- Astronomy Picture of the Day
- View satellite image in Google Maps
- Line of Muritanian desert craters
- (French) A video documentary from Radio Canada
Coordinates: 21°7′29.67″N 11°24′12.96″W / 21.1249083°N 11.4036°W
Retrieved from : http://en.wikipedia.org/wiki/Richat_Structure
