Martian Permafrost May Contain Viable Liquid Water Channels

Mars might harbor a system of liquid water flowing beneath its icy surface. Similar to permafrost on Earth, which is theorized to have thin veins of liquid minerals, new models suggest these veins on Mars could be substantial enough to sustain life.

“For Mars, we’re constantly flirting with the edge of habitability. Initially, I theorized this study would reveal that adequate water wouldn’t exist, thus making microbial life impossible,” states Hannah Sizemore from the Planetary Science Institute in Arizona. “I was mistaken.”

Sizemore and her team analyzed Mars’ soil composition to estimate the amount of icy soil that might actually comprise liquid water and the dimensions of the channels through which it flows. Temperatures on Mars can plummet to -150°C (-240°F), challenging the existence of liquid water. While pure water freezes at 0°C, the presence of salts—widespread on Mars—can significantly lower the freezing point.

The research indicated that it is “surprisingly feasible” to find soil containing over 5 percent liquid water in channels exceeding 5 microns in diameter. This threshold was deemed necessary for a vein to be classified as habitable. “The largest veins we’re referencing are 10 times narrower than a fine human hair,” Sizemore elaborates. “Nonetheless, it’s a sufficiently expansive environment to host microorganisms, allowing for the transfer of nutrients and waste within the ecosystem.”

Based on soil data collected by NASA’s Phoenix spacecraft, which landed on Mars in 2008, these networks of waterways may be prevalent at latitudes above 50 degrees. Sizemore indicated that if life exists on Mars, liquid veins would be prime locations for investigation, proposing that “this is a site where one could land and excavate around 30 centimeters to collect samples.”

The primary concern regarding these veins as potential habitats is their temperature, which can be significantly below what most known life forms can endure. “However, we must exercise caution in applying the limits observed for terrestrial organisms to other life forms, as they do not necessarily define the survival limits for all life that could exist elsewhere,” states Bruce Jakosky from the University of Colorado Boulder. “Ultimately, this study and related research suggest that the existence of life near the Martian surface is not out of the question.”