Toxic Compounds on Mars Could Make it difficult for life to thrive on Red Planet

Toxic Compounds on Mars Could Make it difficult for life to thrive on Red Planet

Toxic compounds in the Martian soil could make it difficult for bacteria to thrive on the planet and could also lead to trouble for other life forms on the red planet, a new research report published in journal Scientific Reports has informed. Mars has high amount of radiation and its atmosphere has much lower concentration of carbon dioxide compared to that on our planet. Scientists have been trying to search for signs of life on Mars and trying to evaluate if the planet could support life in future.

NASA’s Curiosity rover has provided lot of interesting information to scientists about Mars. Viking 1 and 2 spacecrafts have also detected presence of perchlorates in Martian soil. While perchlorates can serve as energy source for bacteria, they can also be toxic in presence of high amount of ultraviolet radiation. Mars faces high amount of ultraviolet radiation and scientists suggest that the perchlorates present in Martian soil could be toxic for bacteria.

Researchers from University of Edinburgh's School of Physics and Astronomy tested their idea by creating conditions similar to that on Mars in a laboratory. The project was conducted by postgraduate student Jennifer Wadsworth and professor Charles Cockell. Researchers steeped the bacteria in a watery solution of magnesium perchlorate. Magnesium perchlorate is most commonly found on Mars. The research team later bombarded ultraviolet radiation with similar intensity to that on Mars, on magnesium perchlorate. Then, the research team checked how bacteria would survive in perchlorate that was bombarded with UV radiation.

Over the course of 60 seconds, the combination of irradiated perchlorates, iron oxides and hydrogen peroxide boosted the B. subtilis death rate by a factor of 10.8 compared to cells exposed to UV radiation alone.

The research paper published in Scientific Reports informed, "These data show that the combined effects of at least three components of the Martian surface, activated by surface photochemistry, render the present-day surface more uninhabitable than previously thought and demonstrate the low probability of survival of biological contaminants released from robotic and human exploration missions."

"It's not out of the question that hardier life forms would find a way to survive" at or near the Martian surface, Wadsworth told Space.com. "It's important we still take all the precautions we can to not contaminate Mars."

The research paper further informed....

The study also suggested that the effect of perchlorates can be compounded by two other types of chemicals found on Mars’ surface, iron oxides and hydrogen peroxide.

In experiments in which all three were present, the combination led to a more than 10-fold increase in death of bacterial cells compared with perchlorates alone.

Scientists have speculated on the influence that perchlorates may have on the habitability of the planet, since their discovery there several years ago.

Bacteria tests

Researchers in the UK Centre for Astrobiology and School of Physics and Astronomy investigated the potential reactivity of perchlorates and their effect on Bacillus subtilis, a bacterium found on spacecraft and common in soils and rocks.

Their experiments showed that when magnesium perchlorate was exposed to UV radiation similar to that on Mars, it became capable of killing bacteria much more effectively than UV light alone.

At concentrations of perchlorate similar to those found on the Martian surface, cells of B. subtilis quickly died.

Damaging environment
Although the Martian surface has been suspected for some time to have toxic effects, the latest study suggests that it may be highly damaging to living cells.

This is owing to a toxic mix of oxidants, iron oxides, perchlorates, and UV energy.

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