Express your nature.

Upload, Share, and Be Recognized.

Join with Facebook
or join manually
X
Comments:

Old Comments:

2011-05-16 11:08:10
This prominent circular feature, known as the Richat Structure, in the Sahara desert of Mauritania is often noted by astronauts because it forms a conspicuous 50-kilometer-wide (30-mile-wide) bull's-eye on the otherwise rather featureless expanse of the desert. Initially mistaken for a possible impact crater, it is now known to be an eroded circular anticline (structural dome) of layered sedimentary rocks