The High Resolution Imaging Science Experiment (HiRISE) camera aboard the Mars Reconnaissance Orbiter captured this beautiful image of the Red Planet's surface. It depicts water ice frozen in channels in the soil that form a fantastic pattern of polygons. Launched in 2006, HiRISE is the most powerful camera humans have ever delivered to another planet. From the University of Arizona's HiRISE project:
Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.
