NASA would like your attention long enough to explain a thing or two about how—
(@NASA) September 04, 2014
—absolutely cool the Cassini-Huygens mission really is.
The NASA and European Space Agency Cassini mission has revealed hundreds of lakes and seas spread across the north polar region of Saturn’s moon Titan. These lakes are filled not with water but with hydrocarbons, a form of organic compound that is also found naturally on Earth and includes methane. The vast majority of liquid in Titan’s lakes is thought to be replenished by rainfall from clouds in the moon’s atmosphere. But how liquids move and cycle through Titan’s crust and atmosphere is still relatively unknown.
A recent study led by Olivier Mousis, a Cassini research associate at the University of Franche-Comté, France, examined how Titan’s methane rainfall would interact with icy materials within underground reservoirs. They found that the formation of materials called clathrates changes the chemical composition of the rainfall runoff that charges these hydrocarbon “aquifers.” This process leads to the formation of reservoirs of propane and ethane that may feed into some rivers and lakes.
And it doesn’t stop there.
No, really. Check this out:
Clathrates are compounds in which water forms a crystal structure with small cages that trap other substances like methane and ethane. Clathrates that contain methane are found on Earth in some polar and ocean sediments. On Titan, the surface pressure and temperature should allow clathrates to form when liquid hydrocarbons come into contact with water ice, which is a major component of the moon’s crust. These clathrate layers could remain stable as far down as several miles below Titan’s surface.
One of the peculiar properties of clathrates is that they trap and split molecules into a mix of liquid and solid phases, in a process called fractionation. Titan’s subsurface clathrate reservoirs would interact with and fractionate the liquid methane from the original underground hydrocarbon lake, slowly changing its composition. Eventually the original methane aquifer would be turned into a propane or ethane aquifer.
You know, our Universe is a really cool place. And we haven’t even left the neighborhood to see what’s out there. Sometimes it seems as if NASA exists to demonstrate the fate of any government agency that actually does its job: budget cuts.
Dyches, Preston, Olivier Mousis, and Nicolas Altobelli. “Icy Aquifers on Titan Transform Methane Rainfall”. NASA. 3 September 2014.