Titan's methane lakes may fizz with nitrogen bubbles

March 16 (UPI) -- Experiments at NASA's Jet Propulsion Laboratory, in Pasadena, Calif., suggest the lakes, seas and rivers on Saturn's moon Titan may feature periodic patches of bubbles.

Tests recreating Titan's surface conditions showed frigid methane liquid can absorb nitrogen. The experiments also showed slight changes in temperature, pressure or composition can cause the nitrogen to swiftly separate from the solution.

The soda-like fizz could explain Titan's "magic islands," patches of land observed appearing and reappearing in lunar lakes.

"Our experiments showed that when methane-rich liquids mix with ethane-rich ones -- for example from a heavy rain, or when runoff from a methane river mixes into an ethane-rich lake -- the nitrogen is less able to stay in solution," JPL scientist Michael Malaska said in a news release.

Researchers found the crystallization of ethane ice on the bottom of Titan's lakes and seas could also squeeze out nitrogen and create an eruption of bubbles. But nitrogen isn't always leaving, there is a complex cycle of inputs and outputs.

"In effect, it's as though the lakes of Titan breathe nitrogen," Malaska said. "As they cool, they can absorb more of the gas, 'inhaling.' And as they warm, the liquid's capacity is reduced, so they 'exhale.'"

The experiments suggest the relationship between Titan's seas and nitrogen is not unlike the relationship between Earth's oceans and CO2.

Scientists hoping to put an underwater vehicle into Titan's seas may have to account for the unbalanced nature of the moon's liquid solution. Heat from a probe's propeller could trigger an eruption of fizz, making it difficult to steer.

Cassini is set to make its final Titan flyby on April 22. If the magic islands are present, the craft is prepared to capture high-resolution photos, so astronomers might distinguish between bubbles, waves or floating solids.