A new NASA study suggests that life might be able to survive beneath the frozen ice on Mars.
While no direct evidence of life on the Red Planet has been found, researchers believe that microbes could potentially thrive in small pools of meltwater under the ice, similar to ecosystems found in icy regions on Earth.
The study, led by Aditya Khuller of NASA’s Jet Propulsion Laboratory, used computer models to show that enough sunlight can penetrate Mars’ ice to support photosynthesis in shallow water below the surface.
On Earth, similar meltwater pockets within ice support life forms like algae, fungi, and cyanobacteria, which use photosynthesis to produce energy.
“If we’re looking for life beyond Earth, the ice on Mars could be one of the most accessible places to search,” Khuller said.
Mars has two types of ice: water ice and carbon dioxide ice. In this study, the researchers focused on water ice, which formed from snow mixed with dust during Martian ice ages over the last million years.
This ancient snow has now turned into ice that is still laced with dust particles.
The dust in the ice plays a key role. While it may block some sunlight, it also absorbs heat, which can melt the ice a few feet below the surface. This process could create small pockets of water within the ice, where microbes might survive.
Can ice melt on Mars?
Scientists have debated whether ice can melt on Mars due to its thin, dry atmosphere.
On the planet’s surface, water ice is thought to sublimate, turning directly from a solid to a gas without melting. However, this process doesn’t necessarily occur below the surface of a dusty glacier or snowpack, where the atmosphere has less influence.
Similar processes happen on Earth. Dust within ice can create “cryoconite holes,” small pockets of meltwater formed when particles absorb sunlight and melt deeper into the ice. These pockets can sustain simple ecosystems, and scientists believe a similar process could happen on Mars.
“This is something we see on Earth,” said co-author Phil Christensen from Arizona State University. “Ice can melt from within as sunlight penetrates it, creating a greenhouse-like effect.”
Photosynthesis below the surface
The study shows that enough light could pass through Mars’ dusty ice for photosynthesis to happen as deep as 9 feet (3 meters) below the surface. The upper layers of ice would not only trap meltwater but also protect it from harmful radiation, which is more intense on Mars due to the lack of a magnetic field.
The study suggests that the most likely places to find such subsurface pools of water would be in Mars’ tropical regions, between 30 and 60 degrees latitude in both the northern and southern hemispheres.
Moving forward, Khuller and his team hope to recreate Mars’ icy conditions in a lab to study how this process might work in more detail.
Their research could guide future human and robotic missions to search for life on Mars in areas where shallow meltwater might exist.
Source: NASA.
