The martian landscape is characterized by blocks that litter the surface. The interest stimulated by these blocks depends on your point of view.
Viewers lacking in imagination see only a rock pile, a sort of cosmic junk heap.
At the other extreme, viewers with a surplus of imagination see all sorts of artifacts, even remnants of former civilizations. Somewhere in between, planetary scientists are impressed by block shape, texture, and color-all clues to rock origin and erosional modification. On the Moon, most blocks are formed by meteoroid impact and accompanying excavation of bedrock. Since impact craters are common features on Mars, this same process of block formation must be represented. In fact, Viking Orbiter images of the Lander 1 site indicate that the rims of several impact craters are visible in Lander images, and may have been responsible for much of the apparent fracturing of bedrock in this region.