The hope of finding life on Mars took a downward turn recently. A study has revealed that the Martian surface contains a toxic cocktail of salt minerals and chemicals that can kill living organisms.
According to The Guardian, experiments with compounds found in the Red Planet’s soil suggest that they are transformed into potent bactericides by the ultraviolet light that sweeps the planet. This sterilizes the Martian surface’s upper layers.
The findings have far-reaching implications for the search of alien life on Mars. Consequently, missions on the planet have to dig deeper underground to find evidence of any past or present life. In fact, the depth of 2 or 3 meters below the surface might be the most hospitable environment to protect the soil and organisms from strong radiation. The research team has suggested that probable Martian life could survive at those depths.
The research team was driven to their study by the discovery of powerful oxidants known as perchlorates in the soil on Mars. Perchlorates were found to kill bacteria cultures of Bacillus subtilis in lab tests on Earth.
"If we want to find life on Mars, we have to take this into consideration and look at trying to find sub-surface life that wouldn't be exposed to these conditions," researcher Jennifer Wadsworth said, as NDTV reported. The expert, however, added that just because perchlorates killed B. subtilis UV radiation’s presence does not necessarily imply that all forms of life, if any, would similarly die. More tests are needed to confirm this.
The research subsequently indicates that the damp streaks detected on the surface of Mars from orbit may not be the major areas to look for alien microbes. This is because the briny areas would probably contain perchlorates, meaning the patches would be even more toxic than the soil surrounding them. The study contains some good news, though. The presence of perchlorates means that organic contaminants left on the Red Planet by robotic exploration, such as the commonly present B. subtilis, would not survive long.