The large jets of water vapour that are observed only in the southern polar region of Saturn’s moon Enceladus can be explained as a manifestation of a waning event of catastrophic renewal of the moon’s crust. Research, published online this week in Nature Geoscience, suggests that such episodes of strong convection could also have played a part in shaping the surfaces of other icy satellites in the Solar System.
Craig O’Neill and Francis Nimmo simulated convection of Enceladus’s ice mantle. They find that occasional episodes during which parts of Enceladus’s ice mantle are recycled into the moon’s interior could explain the present activity and heat loss in the body’s South Polar Region, as well as the heavily deformed surface observed on Enceladus. They estimate that catastrophic convection events occur every 100 to 1,000 million years and last about 10 million years.
The authors conclude that we are currently observing Enceladus in one of its rare phases of resurfacing that make up only about 1-10% of the time.