July 3, 2014
Ocean On Saturnian Moon Titan May Be As Salty As The Dead Sea
Gerard LeBlond for redOrbit.com - Your Universe Online
The inner ocean of Saturn’s largest moon Titan may be as salty as the Dead Sea, according to scientists with NASA’s Cassini mission, which has been collecting gravity and topographic data from the distant Saturnian satellite over the last ten years.
After studying the data, researchers built a model structure of Titan, resulting in a better understanding of the moon’s outer ice shell. The study was published this week in the journal Icarus.
“Titan continues to prove itself as an endlessly fascinating world, and with our long-lived Cassini spacecraft, we’re unlocking new mysteries as fast as we solve old ones,” said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.
Supported by the new findings, previous data indicates that Titan’s ice shell is rigid and is freezing solid. The data also indicates that a high density was required for Titan’s ocean to be like it is, which explains the gravity data gathered, concluding that the ocean most likely has a mixture of sulfur, sodium and potassium, making it extremely salty.
“This is an extremely salty ocean by Earth standards. Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past,” said the paper's lead author, Giuseppe Mitri of the University of Nantes in France.
According to the researchers, the data gathered indicates Titan’s ice crust varies slightly in thickness in different regions, resulting from the moon’s outer shell being rigid and the ocean is slowly crystallizing and turning to ice. If that wasn’t the case, then the shape of the moon would be uniform. However, the new findings reveal that habitability of Titan’s ocean would be difficult. During the freezing process, materials in the ocean would have a limited ability to exchange between the surface and the ocean.
The study also indicates that any release of methane into Titan’s atmosphere is from scattered “hot spots” similar to what formed the Hawaiian Islands. The methane that is released doesn’t seem to be from convection or plate tectonics recycling the ice shell.
Researchers have been interested in how the methane is released into the atmosphere for a long time. Sunlight breaks apart the molecules of methane, but there is about a five percent ratio of the gas in Titan’s atmosphere. For this gas to be continually present, researchers believe there is a geological factor replenishing the methane. However the process is done, it is localized and intermediate.
“Our work suggests looking for signs of methane outgassing will be difficult with Cassini, and may require a future mission that can find localized methane sources. As on Mars, this is a challenging task,” said co-author Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, New York.
FOR THE KINDLE: Space Technologies on Earth: redOrbit Press