Mercury's Rivers of Craters

This view captured by MESSENGER's wide angle camera (WAC) shows many secondary crater chains that originated from a primary impact crater located outside this image to the west. The secondary crater chains are formed as the parent crater-forming event launches ejecta into the surrounding area. The chunks of ejecta dig out their own craters which sometimes overlap to form a long valley-like depression. These features are striking though not uncommon on Mercury's battered surface.