This false-color image shows a Martian dune field near the northern polar cap. The image itself covers an area 30 kilometers wide, but the dune field stretches over an area the size of Texas. In the photo cooler areas have been rendered in bluer tints, while warm areas are shown in yellow and orange. The sun warms the wind-sculpted dunes more than in the valleys that lie between. Complex dune networks like these build up over time as consistent winds push sand and create interactions between individual dunes. (Image credit: NASA/JPL-Caltech/ASU; via Colossal)
Blue Dunes
