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Seeking Europa's Ocean

Published online by Cambridge University Press:  03 November 2010

Robert T. Pappalardo
Robert T. Pappalardo*
Affiliation:
Jet Propulsion Laboratory, California Institute of Technology email: robert.pappalardo@jpl.nasa.gov
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Abstract

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Galileo spacecraft data suggest that a global ocean exists beneath the frozen ice surface Jupiter's moon Europa. Since the early 1970s, planetary scientists have used theoretical and observational arguments to deliberate the existence of an ocean within Europa and other large icy satellites. Galileo magnetometry data indicates an induced magnetic field at Europa, implying a salt water ocean. A paucity of large craters argues for a surface on average only ~40-90 Myr old. Two multi-ring structures suggest that impacts punched through an ice shell ~20 km thick. Europa's ocean and surface are inherently linked through tidal deformation of the floating ice shell, and tidal flexing and nonsynchronous rotation generate stresses that fracture and deform the surface to create ridges and bands. Dark spots, domes, and chaos terrain are probably related to tidally driven ice convection along with partial melting within the ice shell. Europa's geological activity and probable mantle contact permit the chemical ingredients necessary for life to be present within the satellite's ocean. Astonishing geology and high astrobiological potential make Europa a top priority for future spacecraft exploration, with a primary goal of assessing its habitability.

Keywords

Europahabitabilityoceanconvectionice
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S269: Galileo's Medicean Moons: their impact on 400 years of discovery , January 2010 , pp. 101 - 114
Copyright
Copyright © International Astronomical Union 2010

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