Potential for Life in Martian Perchlorate Brines
Perchlorate salts on Mars could allow liquid water to persist on the martian surface as brines, despite the cold and dry conditions.
The potential for life in briny water is currently being studied, and one angle is to look at habitability in terms of water activity. Water activity controls many aspects of liquid solutions, including things like condensation, evaporation, and ice formation. Water activity in perchlorate solutions has only been studied at 298.15 Kelvin (K) and at the freezing point of water.
A new study addresses the lack of information regarding water activity relevant to perchlorate solutions on Mars. The team studied salt concentrations up to near-saturation and temperatures from 298.15 to 178 K. The findings provide new insight into the potential for life on Mars.
The paper, “Water activities of NaClO4, Ca(ClO4)2, and Mg(ClO4)2 brines from experimental heat capacities: Water activity >0.6 below 200 K,” was published in the journal Geochimica et Cosmochimica Acta. The work was supported by the Astrobiology Program through the core program element Habitable Worlds, and through funding from the NASA Astrobiology Postdoctoral Fellowship Program.
