‘Ocean Worlds of Our Solar System’ –NASA’s Stunning Infographic (VIEW)



NASA scientists have detected subsurface oceans on dwarf planet Ceres and a number of outer solar system moons, including Jupiter’s Europa, Saturn’s Enceladus, Neptune’s Triton, and most recently, a vast subsurface ocean on Pluto.

“I believe we are going to have strong indications of life beyond Earth in the next decade and definitive evidence in the next 10 to 20 years,” said NASA’s chief scientits, Ellen Stofan, who anticipates news of the discovery of nearby alien microbes that would expand the number of nooks and crannies life might inhabit throughout the galaxy.

And, just this week according to new data from the Cassini mission, a subsurface ocean lies deep within Saturn’s moon Dione, to Saturn. Two other moons of Saturn, Titan and Enceladus, are already known to hide global oceans beneath their icy crusts, but a new study suggests an ocean exists on Dione as well.

In this study, researchers of the Royal Observatory of Belgium show gravity data from recent Cassini flybys can be explained if Dione’s crust floats on an ocean located 100 kilometres below the surface. The ocean is several tens of kilometres deep and surrounds a large rocky core. Dione is very similar to its smaller but more famous neighbor Enceladus, whose south polar region harbors huge geysers of water vapour.

According to the new study, Enceladus’ ocean is much closer to the surface, especially near the south pole where geysers erupt through a few kilometres of crust. These findings agree well with the discovery last year by Cassini that Enceladus undergoes large back-and-forth oscillations, called libration, during its orbit. Enceladus’ libration would be much smaller if its crust was thicker.

“Like Enceladus, Dione librates but below the detection level of Cassini,” said Antony Trinh, co-author of the new study. “A future orbiter hopping around Saturn’s moons could test this prediction.”

Dione’s ocean has probably survived for the whole history of the moon, and thus offers a long-lived habitable zone for microbial life. “The contact between the ocean and the rocky core is crucial,” said Attilio Rivoldini, co-author of the study. “Rock-water interactions provide key nutrients and a source of energy, both being essential ingredients for life.”



Image Credit: top of page, with thanks to media.bloxi.com



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