Where Light Meets Dark

This panoramic camera image of the soil target whimsically called "Neopolitan" from the Mars Exploration Rover Opportunity's "Eagle Crater" soil survey highlights the border between two different soil types - a lighter, finer-grained unit to the left and a darker, coarser-grained to the right. Scientists are pondering the unusually distinct border between these different soil types. To the lower left and partially hidden by the shadow of the mast is an airbag bounce mark.