By Jay Kakade 18 Oct, 2024
Collected at: https://www.techexplorist.com/possibility-photosynthesis-ice-mars/91327/
On Earth, the ozone layer protects living organisms from damaging ultraviolet radiations from the sun. However, the absence of any protective shield on Mars allows 30% more ultraviolet rays to reach the surface than on Earth.
Recent explorations have exposed the dusty water ice on the surface of Mars at latitudes poleward. As snow, firn, and ice weakly absorb ultraviolet radiation, a recent study published in the journal Communications Earth & Environment hints at possible radiatively habitable zones in dusty ice.
Various organisms can thrive in terrestrial ice, including cyanobacteria, chlorophytes, fungi, and diatoms. As cyanobacteria have developed a high tolerance towards a wide range of temperatures, nutrient deficiency, and UV radiation, they dominate such habitats. While the researchers don’t claim the existence of life on Mars, they hypothesize on the ice in the mid-latitudes to search for alien life.
“We are not stating we have found life on Mars, but instead we believe that dusty Martian ice exposures in the mid-latitudes represent the most easily accessible places to search for Martian life today,” says the research leader Aditya Khuller.
Due to the high concentration of ferric iron, the soil on Mars absorbs more sunlight. Therefore, dusty ice has very low albedo. With the presence of dust in the ice, the penetration depth of sunlight decreases, and the light scatters within the ice.
Researchers think that the protective layer of ice could negate the damage from UV light, and water and light could furnish suitable conditions for photosynthesis. Such suitable areas are called radiative habitable zones.
But still, microbes require temperatures greater than 255 K for cell division, and photosynthesis requires the presence of liquid water. And, the Martian climate is too cold for melting.
Scientists utilized the Delta-Eddington method to develop a model. Researchers found that ice with less than 1% of dust can melt from within. Meanwhile, the overlying snow layer can act as a barrier to prevent evaporation of the water.
“Our analysis shows that despite higher surface ultraviolet radiation levels on Mars than on Earth, it is possible for terrestrial photosynthetic organisms to find locations within exposed ice on Mars with favorable solar radiative conditions,” says the study.
The authors of the study have asserted that the favorable conditions mentioned above don’t guarantee the presence of life on the red planet. However, the study unlocks new avenues for further investigations of radiative habitable zones.
In these efforts, scientists have been trying to recreate similar dusty ice scenarios in the lab, to examine the details more accurately.
Journal Reference
- Khuller, A. R., Warren, S. G., Christensen, P. R., & Clow, G. D. (2024). Potential for photosynthesis on Mars within snow and ice. Communications Earth & Environment, 5(1), 1-7. DOI: 10.1038/s43247-024-01730-y
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