Researchers are exploring how ancient lakes on Mars might have survived for decades under thin layers of ice. This new understanding helps bridge the gap between the geological signs of water and models that suggest a frozen planet.
Led by Eleanor Moreland from Rice University, the study shifts the focus from warmth to insulation. Instead of needing a warm climate like Earth’s, the findings suggest that seasonal ice layers could have protected these lakes during cold periods, allowing them to remain liquid for long stretches.
According to Earth.com, early Mars faced chilly conditions due to a weak sun and a thin atmosphere. Despite this, missions like NASA’s Curiosity rover uncovered features indicating that water persisted far longer than a single thaw would allow. These findings point to mineral deposits and sediments that hint at a stable environment over time.
Moreland shared her excitement about the study, saying, “When our model showed lakes lasting decades under thin, seasonal ice, it felt like we finally had a mechanism that fits what we see on Mars today.” This thin ice wouldn’t resemble the thick glaciers found on Earth. Instead, it would melt and form regularly, slowing evaporation enough to keep water around. This, in turn, may explain the lack of glacial erosion features in Martian lake beds.
Utilizing a tool designed for Earth’s climate, the team adapted the Proxy System Modeling approach to Mars. Given the scarcity of concrete evidence like trees or ice cores on Mars, they relied on data from Martian rocks and rover observations, investing years to reshape the model to fit Mars’ physics 3.6 billion years ago.
This effort led to the development of LakeM2ARS (Lake Modeling on Mars with Atmospheric Reconstructions and Simulations), which included 64 simulations covering 30 Martian years—equating to about 56 Earth years. Some scenarios resulted in lakes freezing completely, while others demonstrated that under slightly different conditions, lakes could maintain seasonal ice that predictably melted.
Professor Sylvia Dee, a co-author, mentioned the model’s adaptability, noting, “It shows that with creativity and experimentation, Earth-origin models can give realistic climate scenarios for Mars.”
The study highlighted the crucial role of thin ice. This ice layer didn’t erase evidence of water; rather, it protected it, leaving minimal geological traces. As Professor Kirsten Siebach pointed out, “Because the ice is thin and temporary, it would leave little evidence behind, explaining why rovers haven’t found clear signs of perennial ice on Mars.”
The preserved shorelines and sediment layers support the idea of water sheltered beneath seasonal ice. This approach doesn’t necessitate a warm, stable climate like Earth’s but allows for intermittent conditions that let surface water last longer than previously thought.
Looking ahead, the team intends to apply the LakeM2ARS model to other Martian regions. If similar findings emerge, it could transform how scientists view Mars’ history of water and ancient habitability.
