Seasonal "blotches" near Mars' south pole: "Inca City"
Filed under pretty pictures, Mars, Mars Reconnaissance Orbiter
Each spring, cold jets erupt from beneath a surface layer of carbon dioxide ice. When they erupt into windless conditions, they create surface features informally known as "blotches."
NASA / JPL / UA
Original image at the HiRISE website
Original image data dated on or about September 24, 2012