Experts are wondering how they work

Jan 29, 2010 07:45 GMT  ·  By

Recently, flybys that the NASA/ESA spacecraft Cassini made of Titan, Saturn's largest moon, have uncovered the existence of giant lakes at the space rock's north and south poles. In addition to the fact that these features appear to be moving with each season, they are also filled with something, and researchers have proposed for a long time that that something is liquid hydrocarbons, as in methane and ethane. Naturally, the prediction is fairly difficult to prove in practice, as a viable scientific mission to Titan has never been planned. That is why experts want to bring the lakes down to Earth, Space reports.

Temperatures on the Saturnine moon generally take on values around minus 179 °C (-290 °F). It's safe to say that it's fairly chilly on Titan's surface, therefore it stands to reason that the lakes are not filled with water. If that were the case, then they would be frozen, and featuring complex and very rare forms of ice. However, Cassini data has suggested that the lakes are liquid, which makes this celestial body the second in our solar system – after our own planet – to have such a trait. “The water is frozen so solid on Titan that you can liken it to silicate rocks on Earth,” University of Arkansas expert Vincent Chevrier explains.

Though Cassini showed that, most likely, the lakes were made up of liquid methane and ethane, researchers don't know yet very much about how these two chemicals behave at such low temperatures, This is largely due to the fact that the substances are regularly gases on our planet, therefore there was no need for them to be analyzed under such extreme environmental conditions. However, in the case of Titan, it was demonstrated that these lakes were not only groundbreaking landscape features, but that they also tended to drive the same chemical and geological processes we see on Earth. This naturally makes them a highly desirable target for planetary scientists, geologists and astronomers.

Chevrier and his team plan to construct what they call a Titan simulation chamber. The device – a two-meter-tall cylinder – will be injected with small quantities of methane and ethane, and then the entire ensemble will be dipped to 95 °K (or –178 °C). This will all be done under a nitrogen gas pressure that will be 50 percent higher than the one naturally existent on our planet, the team reveals. The end-result will be mini-lakes of hydrocarbons on the bottom of the cylinder.

“Titan's surface is rich with geological features similar to those found on Earth but based on different materials. So any lab experiment that can reproduce conditions on Titan and give some pieces of information of the processes that can happen on this moon are important,” Christophe Sotin, who is an expert at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, adds. The JPL is in charge of managing the Cassini mission for the American space agency's Science Directorate, in Washington DC.