Science: Lake detected near equator of Saturn's Titan

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.

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. Near the equatorial lake were hints of four shallow ponds similar in size and depth to marshes on Earth.

Titan is among the few bodies in the solar system with a dense atmosphere, but scientists have wrestled over the source of the thick blanket of nitrogen and methane. Methane gas in the atmosphere is constantly broken up by sunlight and falls to the surface where it is transported back to the poles, condensing to form lakes.

"Titan may have oases," Griffith said. David Stevenson, a planetary scientist at the California Institute of Technology, said the latest find was interesting, but noted that the evidence was indirect.