T he Moon’s most spectacular "hidden" landform. Mare Orientale, a patch of dark lava flows on the western limb of the Moon, is the centre of the best preserved multi-ring impact basin in the solar system. Orientale has two large concentric rims - the 930-kilometer-diameter Cordillera Mountains and 620-km-wide Rook Mountains. Deep fractures associated with the subsidence of material inside these rims allowed mare lavas to seep to the surface.
(Charles A. Wood - Sky and Telescope)
This picture was taken on the 30th September 2002 at aprox 03.30 UT. Equipment: Orion Optics OMC 140, Canon PowerShot A10, Exposure time 1/8th second, ScopeTronix Digi_T mount. Celestron 17mm plössl eyepiece.