Saturn's largest moon Titan has small liquid lakes that run more than 100 metres deep, a new study has revealed. Scientists have known that these lakes exist for some time, but Cassini, the spacecraft that plunged into Saturn’s depths revealed how deep they really are. “Every time we make discoveries on Titan, Titan becomes more and more mysterious,” lead author Marco Mastrogiuseppe of Caltech said in a statement. “But these new measurements help give an answer to a few key questions. We can actually now better understand the hydrology of Titan.”
Scientists have known that Titan's hydrologic cycle works similarly to Earth's -- with one major difference. Instead of water evaporating from seas, forming clouds and rain, Titan does it all with methane and ethane. We tend to think of these hydrocarbons as a gas on Earth unless they're pressurized in a tank. But Titan is so cold that they behave as liquids, like gasoline at room temperature on our planet, according to a Science Daily report.
The best explanation is that there was some seasonally driven change in the surface liquids, said lead author Shannon MacKenzie, a planetary scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. "One possibility is that these transient features could have been shallower bodies of liquid that over the course of the season evaporated and infiltrated into the subsurface," she said.
Adding to the oddities of Titan, with its Earth-like features carved by exotic materials, is the fact that the hydrology on one side of the northern hemisphere is completely different than the that of other side, said Cassini scientist and co-author Jonathan Lunine of Cornell University in Ithaca, New York.
"It is as if you looked down on the Earth's the North Pole and could see that North America had a completely different geologic setting for bodies of liquid than Asia does," Lunine said.
Rosaly Lopes, a NASA planetary scientist not involved in the study, said "Titan is the only world outside the Earth where we see bodies of liquid on the surface.