Could microbes endure just beneath the surface of Mars, in layers of dusty ice exposed to just the right amount of sunlight? A newly published study suggests those might be among the most accessible places to search for signs of life on the Red Planet.
The study, published today in Nature Communications Earth & Environment, is based on models developed using impure ice from Greenland. “We did not find any direct evidence for any microbes on Mars,” study lead author Aditya Khuller told me in an email. “We do find that the depths where the radiation (solar and UV) conditions are favorable for photosynthesis within dusty Martian ice intersect with the depths where dusty ice can melt on Mars.”
Khuller is a researcher at NASA’s Jet Propulsion Laboratory who’s due to join the University of Washington’s Applied Physics Laboratory at the end of the month. The paper’s co-authors include one of Khuller’s mentors, UW professor emeritus Steve Warren, whom Khuller says is “the world’s expert in how radiation interacts with snow and ice.”
Modern-day Mars is a cold, dry world, bombarded with life-killing levels of ultraviolet radiation. But scientists say that the planet would have been far more hospitable to life in ancient times. They suggest there’s a chance that hardy organisms could still be hanging on deep down in subsurface havens.
How deep? And how much of a chance? Those are questions that Khuller, Warren and their colleagues sought to answer by modeling the composition of Mars’ ice.
