NASA discovers Titan doesn't have an ocean, but a slushy ice layer' that increases possibility of life

"For nearly two decades, the prime location for finding life beyond Earth was a truly alien world: Titan, Saturn's largest moon. Beneath its thick orange atmosphere comparable to Earth's and its lakes and seas of methane, a global ocean of liquid water seemed to lie hidden, buried under kilometers of ice. Now, a new study led by NASA scientists forces us to rethink this image: Titan doesn't harbor a subsurface ocean, but rather an immense layer of warm, partially melted ice."

"The conclusion stems from a meticulous re-examination of data from the Cassini probe, which orbited Saturn and flew past Titan multiple times between 2004 and 2017. The gravitational measurements from this robotic spacecraft were interpreted as unmistakable evidence of an ocean beneath the icy surface. The satellite responded excessively to Saturn's enormous gravitational force, deforming as a sphere with a liquid layer inside it would. But not all the measurements captured by the spacecraft could be true at the same time."

Titan possesses a thick orange atmosphere comparable to Earth's, with lakes and seas of methane and previously suspected global ocean beneath kilometers of ice. Re-examination of Cassini radio and gravitational data finds that the moon's deformation under Saturn's gravity is delayed, inconsistent with an instantaneous fluid response expected from a subsurface ocean. The delay indicates a deep layer of warm, partially melted ice rather than a liquid ocean. The presence of partially melted ice implies a range of varied internal environments and raises the potential for life by increasing chemical and thermal gradients. Reconciling all measurements required new data-processing techniques.

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