Solar storm barreling toward Earth this weekend (video) July 13, 2012
NASA launches telescope to seek black holes June 14, 2012
Private SpaceX capsule back in Texas June 14, 2012
Eyes turn skyward as Venus travels across the sun June 5, 2012
Cosmic crash ahead, but Earth will survive May 31, 2012
SpaceX makes historic space station docking May 25, 2012
Dog's ashes may have been sneaked on to space flight May 24, 2012
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.
The findings were detailed in Thursday's issue of the journal Nature.
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.
Scientists do not think this process is driving the presence of mid-latitude lakes and ponds. Rather, they think there may be an underground source of methane that periodically vents to the surface to form the hydrocarbon bodies of liquid.
"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.
If a subterranean source of methane is confirmed, it's a step toward understanding the persistence of methane in Titan's atmosphere, said Stevenson, who was not part of the research team.
More Nation & World Headlines
Protesters to target Chicago shopping on Black Friday Americans hit the road for Thanksgiving President Obama pardons a pair of turkeys Signed editions of Harper Lee novel offered for $1,500 U.S. suspends personnel over botched Afghan attack Russia sends air-defense missiles to Turkey Casey Kasemís widow sued for wrongful death Can a five-hour Alaskan train ride be compelling Thanksgiving viewing?
Our new comment system is not supported in IE 7. Please upgrade your browser here.