Habitability of Icy Worlds: Electrochemical Capacitance of Serpentinizing Hydrothermal Systems

Electrochemical Capacitance of Serpentinizing Hydrothermal Systems Steve Vance Jet Propulsion Laboratory, Caltech, MS 183-401, 4800 Oak Grove Dr., Pasadena, CA 91024 ([email protected]) Differentiated icy satellites and dwarf planets in the size range R ≈ 250− 2000 km constitute a special class of objects sufficiently large for anhydrous and chemically reducing rocky interiors to result from heats of formation, yet small enough to sustain fracturable mantle depths 10-100 times greater than Earth’s crustal thickness. Hydration of rocky mantle minerals by serpentinization provides a means for sustaining the measured release of chemical energy in such worlds. Fluid percolation depths increase as radiogenic heating diminishes, providing a long-lived source of chemicals and energy for putative organisms. In tidally evolved systems such as Europa, periods of high forced eccentricity provide a means for dehydrating and sealing fractured mantle, thereby recharging the global reservoir of geochemical energy.