New Delhi: Scientists believe that melting water beneath Martian Ice can sustain microbial life on the Red Planet today. A team of researchers used sophisticated computer modelling to examine the amount of sunlight that can pass through water ice on Mars, and determined that enough energy can pass through for photosynthesis in shallow pools of meltwater beneath the surface ice. Similar pools of water are also formed on Earth, and are teeming with life including algae, fungi and microscopic cyanobacteria. The researchers have identified locations on the surface of Mars where microbial life can eke out a living today.
Holes in the Matanuska Glacier in Alaska formed by dust particles melting into ice. (Image Credit: Kimberly Casey, CC-BY-NC-SA 4.0).
There are two types of ice on Mars, carbon dioxide ice and water ice. The researchers examined water ice on Mars for the study, which formed in large amounts because of a mixture between snow and ice during a series of Martian ice ages over the past million years. This ice is peppered with specks of dust. The dark dust absorbs more sunlight than the surrounding bright ice, causing the ice to melt and warm up, for a few feet beneath the surface. The planet has a thin, dry atmosphere that prevents the ice from melting and pooling, with the water vapour sublimating away directly in vapour form. However, these conditions are different beneath the surface, where pools of stable water can form.
Martian Microcosms
Dust in ice create so-called cryoconite holes on Earth, because of dust on ice absorbing sunlight. These create pockets of meltwaters beneath the ice, that nourish ecosystems. A paper describing the findings has been published in Nature Communications Earth and Environment. Coauthor of the paper, Phil Christensen says, “This is a common phenomenon on Earth. 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.” A similar process may be working today on Mars.
