loading page

Brine Volume Fraction as a Habitability Metric for Europa's Ice Shell
  • +2
  • Natalie S. Wolfenbarger,
  • Mark G Fox-Powell,
  • Jacob Buffo,
  • Krista M. Soderlund,
  • Donald D Blankenship
Natalie S. Wolfenbarger
Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin, Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, University of Texas at Austin

Corresponding Author:[email protected]

Author Profile
Mark G Fox-Powell
Open University, Open University
Author Profile
Jacob Buffo
Dartmouth College, Dartmouth College
Author Profile
Krista M. Soderlund
University of Texas at Austin, University of Texas at Austin
Author Profile
Donald D Blankenship
University of Texas at Austin, University of Texas at Austin
Author Profile

Abstract

Brine systems in Europa’s ice shell have been hypothesized as potential habitats that could be more accessible than the sub-ice ocean. We model the distribution of sub-millimeter-scale brine pockets in Europa’s ice shell. Through examination of three habitability metrics (water activity, ionic strength, salinity), we determine that brine pockets are likely not geochemically prohibitive to life as we know it for the chloride and sulfate-dominated ocean compositions considered here. Brine volume fraction is introduced as a novel habitability metric to serve as a proxy for nutrient transport and recycling—because of its role in governing permeability—and used to define regions where nutrient-open, nutrient-closed, and relict habitats are stable. Whereas nutrient-closed habitats could exist wherever brine is stable, nutrient-open habitats are confined to meter-scale regions near the ice-ocean interface where freezing is occurring. This classification scheme can help guide future life-detection missions to ocean worlds.
28 Nov 2022Published in Geophysical Research Letters volume 49 issue 22. 10.1029/2022GL100586