17-11-11 NASA probe data show evidence of liquid water on icy Europa

Data from a NASA planetary mission have provided scientists evidence of what appears to be a body of liquid water,equal in volume to the North American Great Lakes,beneath the icy surface of Jupiters moon Europa.The data suggest there is significant exchange between Europas icy shell and the ocean beneath.This information could bolster arguments that Europas global subsurface ocean represents a potential habitat for life elsewhere in our solar system.The data opens up some compelling possibilities,said Mary Voytek,from NASA Headquarters in Washington, D.C.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.NASAs Galileo spacecraft,launched by the space shuttle Atlantis in 1989 to Jupiter,produced numerous discoveries and provided scientists decades of data to analyze.Galileo studied Jupiter,which is the most massive planet in the solar system,and some of its many moons.One of the most significant discoveries was the inference of a global salt-water ocean below the surface of Europa.This ocean is deep enough to cover the whole surface of Europa and contains more liquid water than all of Earths oceans combined.However,being far from the Sun,the ocean surface is completely frozen.Most scientists think this ice crust is tens of miles thick.One opinion in the scientific community has been if the ice shell is thick,thats bad for biology,said Britney Schmidt,from the University of Texas at Austin.That might mean the surface isnt communicating with the underlying ocean.Now,we see evidence that its a thick ice shell that can mix vigorously and new evidence for giant shallow lakes.That could make Europa and its ocean more habitable.Schmidt and her team focused on Galileo images of two roughly circular,bumpy features on Europas surface called chaos terrains.Based on similar processes seen on Earth,on ice shelves and under glaciers overlaying volcanoes — they developed a four-step model to explain how the features form.The model resolves several conflicting observations.Some seemed to suggest the ice shell is thick.Others suggest it is thin.