Tropical Titan Tributaries

So another of my favorite astronomy topics is "planetary" geology, but I'm actually more interested in their "lunar" geology...

You probably know that Saturn has moons, but do you know how many? So far, NASA and JPL's Cassini Solstice mission has been able to find 62 moons orbiting Saturn! That's pretty incredible, right? And even more incredible is that, at least on Saturn's largest moon, Titan, tropical lakes have been found! Many of the moons around some of our solar system's planets have interesting climates and features, and Titan's lakes make it a moon of particular interest. Okay, so the liquid in these lakes in methane, which means that they must be extremely cold. So why are these lakes considered tropical? The adjective merely refers to the location of these lakes on Titan. It sounds cool, though.

You may be wondering how there could be lakes on the moon and how they don't evaporate. The lakes are very shallow, and in some areas may only be ankle deep, so how are they getting recharged? Well, just as Earth has a water cycle of condensation, precipitation, and evaporation (and transpiration, which we can ignore in this analogy, since we don't know if there is life on Titan...yet), Titan has a similar Methane cycle. It also has a thick atmosphere, which may contribute to the lakes and makes the moon difficult to study. However, astronomers do not believe that the Methane cycle provides enough precipitation to supply these extremely large, albeit shallow, lakes, and postulate that "a likely supplier is an underground aquifer," according to Caitlin Griffith, a Cassini team associate. Here is a video from How the Universe Works on the Discovery Channel website explaining how Saturn's satellites may have formed. In the model, a methane comet smashed into one of Saturn's moons, which exploded and recombined into the current planets and rings. This may be the original source of the methane in these lakes. 

Titan's lakes make it the only other celestial body besides Earth to have confirmed existence of liquid on its surface. Astronomers are trying to see if the Saturnian moon shares something else in common with terra firma: life.  The life forms on Titan might inspire hydrogen and expire methane, similar to exotic anaerobic microbes found on Earth. The conditions on Titan are obviously different from those in which the thermophiles live in Earth's oceans, but this form of respiration is one of the possibilities that astrobiologists are considering. 

I hope you found this post interesting, and if you are interested in learning more about Saturn and its moons, I suggest researching the controversial ice volcanoes and how Saturn's rings stay "replenished." Also, if you have any requests for me to blog about, please leave them in the comments section below.