What on Earth is that?
The Richat Structure
in the Sahara Desert of Mauritania
is easily visible from space
because it is nearly 50 kilometers across.
Once thought to be an
impact crater, the
flat middle and lack of shock-altered rock indicates otherwise.
The possibility that the Richat Structure
was formed by a
also seems improbable because of the lack of a dome of igneous or volcanic rock.
Rather, the layered
of the Richat structure is now thought by many to have
been caused by uplifted rock sculpted by
The above image was captured by the
onboard the orbiting orbiting
Why the Richat Structure is nearly circular remains a mystery.