A recent study published in the journal Icarus offers promising news for the prospect of human settlement on Mars: the planet's mid-latitude glaciers are composed of mostly pure water ice, estimated at 80% or more, despite appearing coated in dust on the surface.
This finding, based on data from the Shallow Radar (SHARAD) instrument on NASA's Mars Reconnaissance Orbiter, challenges previous assumptions that these debris-covered glaciers were primarily rock with only a small ice content. Researchers analyzed five distinct glacier sites across Mars, including some in opposite hemispheres, and found a surprising consistency in their high ice-to-rock ratio.
Why this is good news for Mars settlers:
Significant Water Resource: Water is crucial for any long-term human presence on Mars. It can be used for drinking, growing food, and perhaps most importantly, for producing rocket fuel (by splitting water into hydrogen and oxygen). The discovery of readily accessible, high-purity water ice in these glaciers significantly boosts the potential for "in-situ resource utilization" (ISRU), meaning settlers could live off the land rather than relying solely on supplies from Earth.
Accessibility: While some water ice exists in deep permafrost or at the polar caps, these mid-latitude glaciers are potentially more accessible for future missions, as they are not buried as deeply and are located in regions that might be more hospitable for a base.
Implications for Climate History: The uniform purity of these glaciers across the planet suggests a consistent formation and preservation mechanism. This implies that Mars likely experienced either one widespread glaciation event or multiple similar glaciations in its past, offering valuable insights into the Red Planet's climate history.
Potential for Future Exploration: Knowing the composition and extent of these glaciers will help mission planners identify prime locations for future human outposts, maximizing the availability of this vital resource.
The study also indicates that the thick dust layer covering these glaciers acts as an insulator, protecting the ice from sublimation (turning directly from solid to gas) in Mars' thin atmosphere. This further enhances their potential as a stable and valuable water source.
Researchers plan to continue analyzing more glaciers to further solidify this understanding and guide future Mars exploration efforts, including potential missions like the Mars Ice Mapper. This discovery marks a significant step forward in understanding Mars' water budget and its potential to support future human endeavors.