November 16, 2011
From Red Orbit
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Scientists from The University of Texas at Austin said they have discovered a body of liquid water the volume of the North American Great Lakes inside one of Jupiter’s moons.
The team said that the water could represent a potential habitat for life, and many more lakes might exist throughout the shallow regions of Europa’s shell.
The lake is covered by floating ice shelves that appear to be collapsing, which could provide a mechanism for transferring nutrients and energy between the surface and a vast ocean already inferred to exist below the thick ice shell.
“One opinion in the scientific community has been, ‘If the ice shell is thick, that’s bad for biology — that it might mean the surface isn’t communicating with the underlying ocean,’ ” lead author Britney Schmidt, a postdoctoral fellow at The University of Texas, said in a press release. “Now we see evidence that even though the ice shell is thick, it can mix vigorously. That could make Europa and its ocean more habitable.”
The scientists focused on Galileo spacecraft images of two circular, bumpy features on Europa’s surface known as chaos terrains.
The researchers developed a four-step model to explain how the feature form on Europa. The model resolves several conflicting observations, some of which suggest that either the ice shell is thick or that it is thin.
“I read the paper and immediately thought, yes, that’s it, that makes sense,” Robert Pappalardo, senior research scientist at NASA’s Planetary Science Section who did not participate in the study said in a press release. “It’s the only convincing model that fits the full range of observations. To me, that says yes, that’s the right answer.”
The only true confirmation of the inferred lakes would come from a future spacecraft mission designed to probe the ice shell. A mission like this was rated as the second-highest priority flagship mission by the National Research Council’s recent Planetary Decadal Survey.
“This new understanding of processes on Europa would not have been possible without the foundation of the last 20 years of observations over Earth’s ice sheets and floating ice shelves,” Don Blankenship, a co-author and senior research scientist at the Institute for Geophysics, said in a press release.
The research paper “Active formation of ‘chaos terrain’ over shallow subsurface water on Europa” will be published in the journal Nature.