section_path: Extraterrestrial lakes
section_name: Extraterrestrial lakes
paragraph_text: Extraterrestrial lakes
  
  Only one astronomical body other than Earth is known to harbor large lakes: Saturn's largest moon, Titan. Photographs and spectroscopic analysis by the Cassini–Huygens spacecraft show liquid ethane on the surface, which is thought to be mixed with liquid methane. The largest lake on Titan is Kraken Mare which, at an estimated 400,000 km, is roughly five times the size of Lake Superior (~80,000 km) and nearly the size of all five Great Lakes of North America combined. The second largest Titanean lake, Ligeia Mare, is almost twice the size of Lake Superior, at an estimated 150,000 km.
  
  Jupiter's large moon Io is volcanically active, leading to the accumulation of sulfur deposits on the surface. Some photographs taken during the Galileo mission appear to show lakes of liquid sulfur in volcanic caldera, though these are more analogous to lakes of lava than of water on Earth.
  
  The planet Mars has only one confirmed lake which is underground and near the south pole. Although the surface of Mars is too cold and has too little atmospheric pressure to permit permanent surface water, geologic evidence appears to confirm that ancient lakes once formed on the surface.
  
  There are dark basaltic plains on the Moon, similar to lunar maria but smaller, which are called lacus (singular lacus, Latin for "lake") because they were thought by early astronomers to be lakes of water.