section_path: Deserts on other planets
section_name: Deserts on other planets
paragraph_text: Deserts on other planets
  
  Mars is the only other planet in the Solar System besides Earth on which deserts have been identified. Despite its low surface atmospheric pressure (only 1/100 of that of Earth), the patterns of atmospheric circulation on Mars have formed a sea of circumpolar sand more than 5 million km (1.9 million sq mi) in the area, larger than most deserts on Earth. The Martian deserts principally consist of dunes in the form of half-moons in flat areas near the permanent polar ice caps in the north of the planet. The smaller dune fields occupy the bottom of many of the craters situated in the Martian polar regions. Examination of the surface of rocks by laser beamed from the Mars Exploration Rover have shown a surface film that resembles the desert varnish found on Earth although it might just be surface dust. The surface of Titan, a moon of Saturn, also has a desert-like surface with dune seas.