The discovery of a huge methane lake at tropical latitudes on Titan could help scientists better understand the bizarre atmosphere of Saturn's largest moon,
ESA/NASA/JPL/University of Arizona/USGS
In a surprise find, scientists say they have spotted hints of a methane-rich lake and several ponds near the equator of Saturn's biggest moon.
Lakes were previously spied near Titan's polar regions. It was long thought that bodies of liquid could not exist at Titan's midsection because energy from the sun at those latitudes would cause methane pools to evaporate.
"This discovery was completely unexpected because lakes are not stable at tropical latitudes," said planetary scientist Caitlin Griffith of the University of Arizona, who led the discovery team.
By measuring reflected sunlight from Titan's surface and atmosphere, the international Cassini spacecraft detected a dark region near the landing site of Huygens, a companion probe that parachuted to Titan's equator in 2005.
Scientists said further analysis of the dark feature suggests the presence of a 927-square-mile hydrocarbon lake — twice as big as Lake Champlain, a freshwater lake that borders upstate New York and Vermont. Near the equatorial lake were hints of four shallow ponds similar in size and depth to marshes on Earth.