New Evidence for Water Lakes on Europa
A recent research paper appearing in the journal Nature describes evidence for a subsurface lake on Jupiter’s moon Europa. The subsurface lake is estimated to contain a volume of water comparable to the North American “Great Lakes” and may offer new clues for habitable regions beyond Earth. The research paper is authored by Britney Schmidt (University of Texas at Austin), a postdoctoral fellow at the university’s Institute for Geophysics.
Schmidt and her team believe that this discovery increases the potential for life, since the lake is covered by floating ice shelves which appear to be collapsing. The processes the ice shelves are subjected to could provide a way to transfer nutrients and energy from Europa’s surface and the vast ocean already thought to exist below the moon’s icy crust.
“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,’ ” said Schmidt. “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.”
Schmidt and her team based their findings on research using imagery taken by the Galileo spacecraft. Specifically, the team used image data showing two regions Europa’s surface which feature chaos terrains. By applying knowledge of similar ice shelves and glaciers covering volcanoes on Earth, the team developed a model to show how the chaos terrains might form on Europa. The model appears to resolve many conflicting observations, and may help determine just how thick (or thin) Europa’s icy crust is.
Mary Voytek, director of NASA’s Astrobiology Program, commented on the research, stating: “The data opens up some compelling possibilities, however, scientists worldwide will want to take a close look at this analysis and review the data before we can fully appreciate the implication of these results.”
If Schmidt’s results are confirmed, this could provide significant motivation for NASA to green-light future exploration missions to Europa. Currently, such a mission is rated as the second-highest priority flagship mission by the National Research Council’s recent Planetary Science Decadal Survey.
You can view a video animation showing how the subsurface lakes on Europa may form at: http://www.utexas.edu/know/2011/11/16/europa_great_lake/
If you’d like to learn more about the history of the Galileo mission, visit: http://solarsystem.nasa.gov/galileo/