https://www.abovethenormnews.com/2025/05/19/frozen-treasure-mars-ice-deposits-found-inches-below-surface/

Frozen Treasure: Mars Ice Deposits Found Inches Below Surface
By
David Freeman -
May 19, 2025

The surface of Mars stretches out in a seemingly endless reddish-brown desert. Yet beneath this dusty exterior lies a resource more valuable than gold for future explorers – water ice, potentially just inches below the surface in some regions of the Red Planet.

A team of planetary scientists led by Erica Luzzi from Constructor University Bremen recently uncovered compelling evidence that substantial volumes of ice lurk just beneath the Martian soil in northern Amazonis Planitia. Their findings, published in the Journal of Geophysical Research: Planets, map out three specific candidate landing sites designated AP-1, AP-8, and AP-9 that show unmistakable signs of accessible ice deposits.

Walking across these Martian plains, future astronauts would traverse a landscape dominated by distinctive polygonal patterns etched into the ground. These polygons, averaging about 11 meters in diameter, aren’t mere surface features – they’re signposts pointing to ice hidden below. The scientists measured nearly 9,000 of these polygons and calculated that the ice table might sit a mere 8-12 centimeters beneath the surface – shallow enough to access with simple tools.

“The polygons form through thermal contraction of the ground in winter,” explains the research paper. “Similar features occur in Earth’s polar regions where permafrost exists.” The presence of these polygons across vast stretches of the Martian mid-latitudes suggests extensive ice deposits.

The evidence for ice doesn’t end with polygonal terrain. The research team documented a fascinating array of landforms that tell the story of ice’s influence on shaping the Martian landscape:

Near one of the studied sites, a fresh impact crater exposed bright blue material on its wall – pure ice, visible 50-60 centimeters below the surface. This ice patch gradually faded as researchers observed it over several years, confirming that the exposed ice was sublimating directly into Mars’ thin atmosphere.

Across the region, strange landforms called “brain coral terrain” feature winding ridges resembling the surface of a brain. These formed as ice gradually sublimated, causing the ground above to collapse in intricate patterns.

Expanded craters dot the landscape, their rims partially melted away by sublimation. Unlike pristine impact craters, these deformed depressions tell a tale of ice loss over thousands or millions of years.

Most intriguing are the rounded mounds rising 4-10 meters above the surrounding plains, bearing striking resemblance to Earth’s periglacial pingos – ice-cored hills formed when groundwater freezes. Their presence raises tantalizing questions about past liquid water in a region now cold and dry.

The polygonal patterns carving up the Martian surface come in two distinct varieties. Knobby Polygonal Terrain (KPT) features high-centered polygons with raised knobs at their centers reaching heights of 40-166 centimeters. Meanwhile, Smooth Polygonal Terrain (SPT) displays gentler high-centered polygons rarely exceeding 40 centimeters in height.

These different morphologies reveal the complex interplay between ice and Martian climate. The knobby areas likely experienced more intense sublimation, where ice directly transforms from solid to gas in Mars’ thin atmosphere. This process gradually deepens the troughs between polygons while leaving the centers raised.

The transition zones between polygonal terrain and brain coral terrain tell an even more fascinating story. In some places, the boundary appears sharp and defined; in others, the two landforms blend gradually, with polygon patterns slowly dissolving into the labyrinthine patterns of brain coral terrain.

Scientists mapped 353 arcuate ridges in the AP-1 area alone—curved formations following a consistent northwest-southeast orientation. These ridges, sometimes coinciding with the partially preserved rims of expanded craters, point to a period when buried ice began to retreat, leaving behind these distinctive fingerprints on the landscape.

Beneath some of these landforms lies excess ice—pure or nearly pure water ice rather than just ice-cemented soil. The impact crater that exposed blue ice provides the strongest evidence. The HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter captured images of this crater in December 2015, showing a bright blue patch on the northeast-facing interior wall. Follow-up observations in 2017 and 2019 revealed the ice slowly disappearing as it sublimated into the Martian atmosphere.

The ice didn’t form recently. Analysis suggests these buried ice sheets might be tens of millions of years old, deposited during periods when Mars’ axial tilt was significantly greater than today’s 25 degrees. During high-obliquity periods, temperatures at the mid-latitudes dropped while atmospheric water content increased, allowing ice to accumulate near the surface.

As Mars’ obliquity decreased to current levels, this ice became unstable but managed to survive beneath a protective layer of dust and regolith. The research team proposes that this “lag deposit”—material left behind as ice sublimated—now shields the remaining ice from rapid loss to the atmosphere.

The polygons themselves are much younger, estimated to be between 150,000 and 10 million years old. The fact that these polygons continue undisturbed across degraded crater rims suggests the thermal contraction process occurred after or during the onset of crater expansion through sublimation.

The value of these ice deposits extends far beyond their utility for astronauts. They represent pristine scientific treasures for understanding Mars’ climate history and potential for past or present life.

Ice acts as a time capsule, potentially preserving a record of Mars’ atmospheric composition spanning millions of years. On Earth, scientists drill ice cores in Antarctica and Greenland to study ancient climate patterns—similar techniques could reveal Mars’ climatic past.

The interface between ice and regolith creates unique microenvironments where liquid water might occasionally exist, even under current Martian conditions. These microscopic films of water could provide habitats for resilient microorganisms—if life ever evolved on Mars.

Examining the composition of this ice could also solve long-standing mysteries about Mars’ loss of water over time. Most of Mars’ ancient oceans and rivers disappeared billions of years ago, but traces remain locked in these subsurface ice deposits.

The striking resemblance between certain Martian landforms and Earth’s periglacial features opens new avenues for comparative planetology. Arctic and Antarctic regions on Earth, particularly the Dry Valleys of Antarctica, provide valuable analogs for understanding how ice shapes planetary surfaces under extreme conditions.

Even the patchiness of the ice distribution tells an important story. The variable presence of ice in nearby craters suggests complex local factors influencing ice preservation. Understanding these factors might reveal new insights into how permafrost responds to environmental changes—knowledge applicable to Earth’s rapidly warming polar regions.

The existence of near-surface ice transforms our approach to Mars exploration. Current NASA and international plans increasingly factor in these discoveries when selecting landing sites for both robotic and eventual human missions.

SpaceX has reportedly considered Arcadia Planitia as a potential landing region for its ambitious Starship program, which aims to establish the first human presence on Mars. The relative flatness of sites like AP-1, AP-8, and AP-9, combined with accessible ice, makes them prime candidates.

Before humans arrive, robotic missions will likely target these ice-rich regions. A stationary lander equipped with a drill could confirm ice depths and composition, while rovers could map ice distribution across broader areas.

The patchy nature of the ice distribution highlighted in the study presents both challenges and opportunities. Future missions must carefully characterize local variations to ensure reliable resource access, potentially using ground-penetrating radar to map subsurface ice before committing to specific settlement locations.

The discovery of near-surface ice in this region transforms our understanding of Mars’ potential for human exploration. The three mapped sites – AP-1, AP-8, and AP-9 – represent prime candidates for future landing missions, offering not just scientific value but practical resources.

Water ice serves multiple critical functions for Mars missions: converted to liquid, it provides drinking water; split into hydrogen and oxygen, it creates breathable air and rocket propellant. The alternative – shipping these essential resources from Earth – would dramatically increase mission costs.

The relatively flat terrain at these sites offers additional advantages for landing spacecraft safely. Site AP-1 sits at an elevation of approximately -4,130 meters, with minimal topographic variations – only 31 meters of relief across the entire mapped area. While Mars’ surface hosts mountain ranges rising 20+ kilometers, these gently undulating plains present minimal hazards for touchdown.

Located between 39.8°N and 40.75°N latitude, these sites receive significantly more solar illumination than polar regions where ice is more abundant at the surface. This balance between ice accessibility and sunlight availability makes northern Amazonis Planitia uniquely suited for sustaining human presence.

Despite the promising findings, the researchers caution that the ice distribution appears patchy. Some recent impact craters in the region exposed ice, while nearby craters of similar size and age did not. This patchiness suggests local variations in ice depth or abundance that future missions must consider in their planning.

The red dust of Mars may appear lifeless and barren, but these new findings confirm what science fiction writers have long imagined—Mars holds resources that could sustain human explorers. Beneath the alien landscape of polygons, brain coral terrain, and pingo-like mounds lies the key to making Mars a second home for humanity. The ice of Mars, locked away for millions of years, may soon feel the touch of human hands.

Source:

Luzzi, E., Heldmann, J. L., Williams, K. E., Nodjoumi, G., Deutsch, A., & Sehlke, A. (2025). Geomorphological evidence of near-surface ice at candidate landing sites in northern Amazonis Planitia, Mars. Journal of Geophysical Research: Planets, 130, e2024JE008724. https://doi.org/10.1029/2024JE008724