NASA: “Confirms Global Ocean on Saturn’s Moon Enceladus”






NASA scientists say that they've confirmed that an ocean covers the entire moon Enceladus -a 500km-wide body in the outer Solar System. A paper published this week in the journal Icarus images from NASA's Cassini orbiter display evidence of a massive sea. Scientists analyzed seven years worth of high resolution images from the Cassini orbiter to track how the moon wobbles to concluded that the moon's ice crust must float free from the moon's solid rocky core — which would only be possible if an ocean covered the entire world, making the potential for life a distinct possibility. Previous research has hinted that the moon has the kind of geological activity necessary for the evolution of life.

"This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right," Peter Thomas, a Cassini imaging team member at Cornell University and lead author of the new paper, said in a statement.

"If the surface and core were rigidly connected, the core would provide so much dead weight that the wobble would be far smaller than we observe it to be," said Matthew Tiscareno, a Cassini scientist based at the Seti Institute. "This proves that there must be a global layer of liquid separating the surface from the core."

"This is a major step beyond what we understood about this moon before, and it demonstrates the kind of deep-dive discoveries we can make with long-lived orbiter missions to other planets," co-author Carolyn Porco said. "Cassini has been exemplary in this regard."




The Cassini Mission is winding up its observations in the Saturn system, but still has another couple of close passes of Enceladus this year.

The first hint that led to the discovery was the detection of a disturbance in magnetic fields produced by the presence of what appeared to be an atmosphere. NASA scientists determined that the moon was venting huge jets of water vapor containing salts and organic molecules through south polar surface cracks dubbed tiger stripes. Models were created to explain how liquid water could be maintained, and how it might be an ocean feeding the jets.

The Daily Galaxy via NASA/JPL and the BBC.




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