Dazzling Dunes on Mars

As NASA's Opportunity rover creeps farther into "Endurance Crater," the dune field on the crater floor appears even more dramatic. On the left, an approximate true-color image highlights the reddish-colored dust.

On the right, a false-color version of the same image shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a "blue" tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules ("blueberries") that accumulate on the flat surfaces.