Thin Ice May Have Helped Ancient Lakes Survive on Mars
One of the mysteries of the Martian landscape is the presence of numerous valleys and lake bottoms, which appear to have been shaped by running water in ancient times. Simulations of what Mars might have looked like eons ago suggest the Red Planet was likely too cold to support liquid water. A new analysis has identified a solution that could explain how frigid Mars was home to watery lakes.
The study was published in AGU progress.
Learn more: Volcanic activity on Mars could help the search for life on other planets
Where is the ice on Mars?
Mars’ ancient lake basins had confounded many planetary scientists who expected to find evidence of large ice caps on the planet’s surface.
“Seeing ancient lake basins on Mars without clear evidence of thick, long-lasting ice made me wonder if these lakes could have held water for more than a single season in a cold climate,” Eleanor Moreland, a planetary scientist at Rice University and co-author of the study, said in a press release.
The new analysis by Moreland and colleagues used a climate model adapted to Martian weather conditions. On Earth, researchers can reconstruct the past using biological indicators, such as tree ring patterns, to study ancient climates. The treeless deserts of Mars don’t contain records that are easy to analyze, so the team instead used data collected by the Mars rover. Curiosity as it passed through Gale Crater, an ancient impact site found on the equator of Mars. These machines had previously collected rock and mineral samples that could serve as proxies.
Over years of work, the authors tweaked the parameters of their model until it resembled Mars as it was 3.6 billion years ago. The research team focused on how Martian lakes might have existed at that time and named their new model Lake Modeling on Mars with Atmospheric Reconstructions and Simulations (LakeM2ARS).
The model showed that lakes, like those found in Gale Crater, did not need thick ice to survive as long as climate conditions were stable.
“When our new model started showing lakes that could last for decades with only a thin layer of ice disappearing seasonally, it was exciting to finally have a physical mechanism to match what we see on Mars today,” Moreland said.
The simulations essentially created a virtual Martian lake and then tested its durability over a period of 30 Martian years (56 Earth years) under different climate conditions.
“It was fun to think about how a lake model designed for Earth could be adapted to another planet, although that process came with a lot of debugging when we had to change, for example, gravity,” planetary scientist and co-author Sylvia Dee, who originally designed the model, said in a press release.
Martian lakes survive on thin ice
In some simulations, a thin layer of ice at the top of the lake acted as an insulator, minimizing water loss, while allowing enough sunlight to pass through to heat the lake during warmer periods. Although the average air temperature in the simulations remained below freezing most of the time, the lake water remained at a similar depth. It is important to note that such a thin ice sheet would leave few traces, which explains why there is no evidence of thick ice sheets or glaciers on Mars.
The researchers now plan to apply their model to other Martian landscapes showing signs of ancient water. They also want to improve their simulation by adding factors such as atmospheric change and groundwater flow.
“If similar trends emerge across the planet, the results would support the idea that even a fairly cold early Mars could contain liquid water year-round, a key ingredient for environments to be suitable for life,” Moreland said.
Learn more: Dust devils on Mars crackle and pop with electricity, showing how sparks fly in Martian storms
Article sources
Our Discovermagazine.com editors use peer-reviewed research and high-quality sources for our articles, and our editors review the articles for scientific accuracy and editorial standards. See the sources used below for this article:
