NASA scientists suggest that ancient microbial life might still survive under the icy surface of Mars, despite years of exploration aimed at finding evidence of life on the red planet.
A recent study indicates that specific conditions under frozen water ice could allow microbes to perform photosynthesis, potentially supporting life.
Potential for Life in Martian Ice
Using computer models, the research team focused on shallow pools of water that could exist beneath the water ice on Mars. They believe that sunlight could penetrate through the ice and reach these pools, similar to ecosystems found on Earth where algae and microscopic organisms thrive in comparable conditions, according to Nature.
Lead author Aditya Khuller from NASA's Jet Propulsion Laboratory stressed the importance of these icy areas, stating that they may be the best locations to search for life beyond Earth.
Mars features two types of ice: water ice and frozen carbon dioxide, with this study concentrating on water ice. Scientists theorize that large amounts of water ice formed during ancient ice ages on Mars, when snow mixed with dust.
This dust can block some sunlight, but it can also absorb heat and cause the ice to melt slightly beneath the surface, creating pockets of liquid water.
However, the Martian atmosphere presents challenges. Scientists are unsure if water ice can melt on the surface due to the thin air that may cause it to turn into gas instead. Still, researchers think that water ice located deeper beneath the surface might remain stable and not be affected by these atmospheric conditions.
On Earth, similar processes create cryoconite holes-small cavities in ice that develop when dust absorbs sunlight and melts the surrounding ice. This melting can create pockets of water where life forms can thrive, said NSF.
Co-author Phil Christensen from Arizona State University said that this phenomenon allows ice to melt from the inside out, rather than just from the top.
Sunlight Penetrates Martian Ice
The new research indicates that sunlight could reach up to three meters below Mars' surface, making photosynthesis possible in some areas. The protective ice layers help shield these water pools from harmful radiation from the Sun, which is particularly intense on Mars due to its weak magnetic field.
In earlier studies, Christensen and Khuller discovered liquid water could form within the snow on Mars, suggesting that melting ice might have played a role in shaping the planet's landscape. They now believe that the dusty water ice essential for these ecosystems could be found in Mars' tropical regions.
Looking ahead, the research team plans to simulate the conditions of Martian water ice in laboratories on Earth. By mapping out where these shallow water pools might exist, scientists hope to identify new landing sites for future missions, whether robotic or human.
