Titan, Saturn鈥檚 largest moon, may have its own Dead Sea. A fake lake simulating conditions there hints that the moon may host ethane pools brimming with benzene, just as the Dead Sea on Earth is packed with salt.
Titan is arguably the most Earth-like body in the solar system, boasting lakes, rivers, clouds and rainfall. But the moon鈥檚 frigid temperatures mean its liquids are hydrocarbons like ethane or methane, rather than water. When sunlight interacts with the atmosphere it regularly creates fresh organic compounds like benzene 鈥� a chemical found in gasoline 鈥� and these fall like snow.
鈥淭itan is a very similar Earth 鈥� just totally different,鈥� says , who headed up the experiment at the Jet Propulsion Laboratory in Pasadena, California. 鈥淲e鈥檙e trying to figure out how the moon works as a whole.鈥�
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Malaska and his colleagues wondered how much of this snow could dissolve in the lakes. They filled a small tube with liquid ethane, chilled it to a Titan-like -179鈥壜癈 and added benzene.
To their surprise, the benzene dissolved quickly, despite the cold temperatures. This suggests that over geological timescales, Titan鈥檚 lakes have become saturated with organic compounds.
Excess benzene could build up in a mud-like sludge on the shores and on the lakes鈥� floors. Some of these deposits could be eroded by ethane rain, forming a complex landscape resembling a limestone filled with sinkholes, caves and underground streams.
, the NASA spacecraft dedicated to Saturn, may be able to back up the team鈥檚 findings if it finds signs of the benzene sludge or karst terrain when it flies past Titan on 21 August. Meanwhile, the researchers plan to simulate more lakes in the lab to see how well other organic materials like carbon dioxide, hydrogen cyanide and butane dissolve.
Experiments like this one can help us understand Titan鈥檚 landscape better, but the organic materials we have here on Earth may not be good analogues for those found elsewhere, says at Johns Hopkins University in Maryland.
鈥淚t鈥檚 certainly a step towards trying to understand what鈥檚 going on in a set of physical processes that are just the same as on Earth, but obviously the conditions and the working materials are very different,鈥� he says. 鈥淭hat is a seam that runs throughout Titan science.鈥�
Journal reference: Icarus, DOI: 10.1016/j.icarus.2014.07.022
