9 September 2006
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of rings on the martian northern plains. Each ring marks the location of a filled and buried (or, in some cases, mostly-filled and nearly-buried) impact crater. The dark spots on some of the rings are boulders -- or clusters of smaller rocks-associated with the buried craters.
Location near 68.7°N, 288.6°W
Image width: ~3 km (~1.9 mi)
Illumination from: lower left
Season: Northern Summer