Viking Lander Trenches
This color view is a Viking 2 Lander close-up of the surface of Mars. The metal cylinder at right is the shroud (or cover) for the surface sampler instrument, which was ejected after landing. To the left of it are trenches dug by the sampling arm, and at lower right part of one of the lander's footpads can be seen. Note the holes in the rocks, which appear to be vesicles produced by gas bubbles when the rocks first solidified from lava.
Full caption is available here.