Jupiter's moon may have lakes, and thus life
Of all the geological mysteries of the solar system - and they are legion - perhaps none hold as much intrigue as huge piles of jumbled-up icebergs strewn across the cracked and mottled surface of Europa, Jupiter's ice-locked moon.world Updated: Nov 17, 2011 23:47 IST
Of all the geological mysteries of the solar system - and they are legion - perhaps none hold as much intrigue as huge piles of jumbled-up icebergs strewn across the cracked and mottled surface of Europa, Jupiter's ice-locked moon.
A new theory explains these vast "chaos terrains" as the tips of subsurface lakes that well up and warm the surface. The existence of such lakes would thrill scientists seeking life beyond Earth, a group long drawn to Europa.
"Europa has the best chance of having life there today," said Britney Schmidt, who studies the moon at the University of Texas at Austin and led the new study appearing in the journal Nature.
Such lakes could provide a habitat for life or act as channels for organic compounds on Europa's surface to be drawn into the moon's far deeper ocean, said Don Blankenship, a geophysicist and Europa specialist also at the University of Texas.
In the 1990s, Nasa's Galileo probe found strong evidence of a deep, briny ocean covering the entire moon far beneath the icy surface. The discovery of the moon-girdling ocean immediately prompted speculation that such an environment could foster life.
But to do so, scientists said, organic compounds from Europa's surface would need to find their way through the ice.
Subsurface lakes - and the process that creates them - would provide just such channels. "If Europa is habitable, we need to get material from the surface down into the deep interior, down into the ocean," Schmidt said.
Beyond raising hopes for one day finding life on Europa, the theory neatly explains the chaos terrains that litter half of the moon's surface.
Schmidt arrived at the theory after she traveled to Antarctica, which hosts a hundred or more subsurface lakes. If such subsurface lakes exist on Europa, they would hold more water than all five Great Lakes, Schmidt said.
"I think they present a compelling story," Hand said of the research group. "Unfortunately, we have very limited data from Europa."
Schmidt acknowledges that the idea is still a theory.
But there is a way to test it: Fly another probe to Europa and peer beneath its surface with powerful radar.
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