Since liquid water is a key ingredient for life as we know it, NASA has adopted the theme "follow the water" as an
strategy for exploring Mars. Recently, Renno et al.1,2 showed evidence that liquid saline-water exists in areas disturbed
by the Phoenix Mars Lander. Moreover, they argued that the thermodynamics of freeze-thaw cycles leads to the
formation of concentrated saline solutions (brines) with freezing temperatures much higher than current summer ground
temperatures where ground ice exists near the surface and therefore liquid saline-water should be common on Mars.
Here we summarize these ideas, present some new results, and discuss their implications for astrobiology. We propose a
strategy for searching for liquid saline water on Mars and argue that NASA's theme for the exploration of Mars should
be updated to "follow the liquid water."
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