Water Activity and the Challenge for Life on Early Mars

@article{Tosca2008WaterAA,
  title={Water Activity and the Challenge for Life on Early Mars},
  author={Nicholas J. Tosca and Andrew H. Knoll and Scott M. McLennan},
  journal={Science},
  year={2008},
  volume={320},
  pages={1204 - 1207}
}
In situ and orbital exploration of the martian surface has shown that acidic, saline liquid water was intermittently available on ancient Mars. The habitability of these waters depends critically on water activity (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(a_{\mathrm{H}_{2}\mathrm{O}}\) \end{document}), a thermodynamic measure of salinity, which, for terrestrial organisms, has… 

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