(Newser) – University of Arizona researchers have discovered a massive methane lake in the arid tropics of Titan, they announced today, suggesting that Saturn's biggest moon may have subterranean channels of the liquid. Titan has long been known to contain liquid methane, which forms pools, clouds, and rains much as water does on Earth, but until now it's always been concentrated at the poles, Space.com explains. Scientists assumed its tropics were too hot for anything similar.

The findings were based on readings from the Cassini spacecraft. "This discovery was absolutely not expected," the lead researcher says. "Lakes at the poles are easy to explain, but lakes in the tropics are not." She says the lake is roughly the size of Utah's Great Salt Lake. "Our work also suggests the existence of a handful of smaller and shallower ponds similar to marshes on Earth with knee- to ankle-level depths." (Read more University of Arizona stories.)

