The UA's Phoenix Lander opened new trenches at its Martian landing site looking for new materials to analyze and examining the soil and ice subsurface structure.
The team described "the surface of the ground throughout the arctic plain where Phoenix landed is patterned in polygon shapes like those of permafrost areas on Earth, where the ground goes through cycles of swelling and shrinking. Some of the recent and planned digging by Phoenix takes advantage of landing within arm's reach both of the centers of polygons and the troughs between polygons. For example, the "Stone Soup" trench has been dug in a trough in the "Cupboard" excavation area, near the western end of the arm's workspace. The team plans to dig in this zone as deep as possible to study properties of the soil and ice deep in a polygon trough."