Open AccessEnergy for biologic sulfate reduction in a hydrothermally formed ocean on Europa
Author(s) -
Zolotov Mikhail Y.,
Shock Everett L.
Publication year - 2003
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002je001966
Subject(s) - sulfate , hydrothermal circulation , environmental science , seawater , autotroph , energy source , environmental chemistry , chemistry , oceanography , geology , petroleum , paleontology , organic chemistry , seismology , bacteria
Formation of a sulfate‐bearing ocean on Jupiter's satellite Europa by quenched hydrothermal fluids provides a source of metabolic energy for low‐temperature sulfate‐reducing organisms that use dissolved H 2 as an electron donor. Inhibition of thermodynamically favorable sulfate reduction in cooled hydrothermal fluids creates the potential for biologic reduction. Both high temperature and reduced conditions of ocean‐forming hydrothermal solutions favor sulfate reduction in quenched fluids. The maximum amount of energy available to support autotrophic sulfate reduction is on the order of a few kilojoules per kilogram of water and is limited by the low abundances of either H 2 or sulfate in ocean‐forming fluids. Although this irreplaceable energy source might have supported early life on Europa, maintenance of biologic sulfate reduction throughout the ocean's history would require a supply of organic compounds from endogenic sources or from the satellite's surface.