Eastern Sea

Eastern Sea

Courtesy of NASA

http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=798


The Eastern Sea or Orientale Basin is located on the western limb of the Moon and only partially visible from Earth. The structure of the Eastern Sea is more visible than other mare because it is relatively unflooded by basalt. It is believed to be the youngest impact basin on the Moon. Three distinct basin rings are visible. The outer ring defines the basin rim and is 930 km in diameter.

This image was taken by Lunar Orbiter 4.