APOD 3.1 Dark Sand Cascades on Mars

This photograph taken by the Mars Reconnaissance Orbiter shows what appears to be small trees on the surface of Mars. The features in the picture were captured near the North Pole of Mars, which is covered in frozen carbon dioxide. As Spring approached, the carbon dioxide ice started to melt, which made the dark sand on the interior of the Martian sand dunes more visible. When the sand is near the top of the dune, it is common for the sand to streak down the side of the dune and leave dark streaks. These streaks are what many people confuse with trees. The streaks appear to be trees in front of the lighter regions of sand that cast no shadows. When the image was enlarged, it was discovered that the sand slides were occurring while the picture was being taken.