Is there life on Mars? Scientists have been seeking an answer to this question for a long time. Although no concrete evidence has been found till date, a latest study by NASA has sparked curiosity. The US space agency suggests that microbes might find a potential home beneath the frozen water on the red planet's surface.
Based on computer modelling, the authors of the study have discovered that the amount of sunlight that penetrates the water ice could be enough for photosynthesis to occur in the shallow pools of meltwater beneath the surface of that ice.
The process of photosynthesis is utilised by plants and other organisms for converting light energy into chemical energy in search of food.
On the Earth, similar pools of water that form within ice are found to teem with life, including algae, fungi, and microscopic cyanobacteria -- all of them derive energy from photosynthesis.
What does the study suggest?
The NASA research was led by Aditya Khuller, who is associated with the space agency's Jet Propulsion Laboratory (JPL) in Southern California. The paper was published in Nature Communications Earth & Environment.
"If we're trying to find life anywhere in the universe today, Martian ice exposures are probably one of the most accessible places we should be looking," Khuller said.
Since Mars has two kinds of ice -- frozen water and frozen carbon dioxide -- the research team looked at the water ice as a potential host of life.
Tracing its origin, the researchers said that large amounts of it had formed from snow mixed with dust which had fallen on the surface during a series of Martian ice ages in the past million years. The ancient snow, which has now solidified into ice, is still peppered with specks of dust, it added.
Even though these dust particles may obscure light in the ice's deeper layers, they hold the key to explaining how subsurface pools of water could form within ice after getting exposed to the Sun.
"Dark dust absorbs more sunlight than the surrounding ice, potentially causing the ice to warm up and melt up to a few feet below the surface," NASA states.
The study's co-author, Phil Christensen of Arizona State University in Tempe, has been studying ice on Mars for the past few decades.
"Dense snow and ice can melt from the inside out, letting in sunlight that warms it like a greenhouse, rather than melting from the top down," he said.
Aditya Khuller and his team now hope to re-create some of Mars' dusty ice in a lab to study it closely.
