By Sarah Romero
Death on the surface of the red planet.A new study developed by scientists from theUniversity of Edinburgh(UK) has concluded thatsalt minerals on the surface of Mars kill bacteria in minutes.
Until now, scientists had their suspicions about whether microorganisms could actually survive on the surface of the red planet. Now, with lab tests in hand,the incontestable confirmation that any little green bacteria is doomed in contactwith the compounds of the Martian soil, it presents us with the difficult reality of the possibility of growing - potatoes, for example - there.
What is the root of the problem?
The ‘fault’, in this case, lies with the Martian chemical compounds, which containperchlorates(first detected in 2008). These salty compounds are considered toxic to people, butthey are not necessarily a problem for microbes. They are important because they keep surface water in a liquid state (essentially brine), and it was believed that it could also be beneficial to life.
However, the researchers found thatwhen exposed to intense ultraviolet light (replicating the one on Mars), everything becomes very dark for any life formPerchlorates killed any trace of bacteria. "Perchlorate, although stable at room temperature, is a powerful oxidant when activated, for example at high temperatures," the authors write.
The bacteria they conducted the experiments with wasBacillus subtilis, a very common microorganism in spacecraft.None of the bacteria survived this test.In fact, they died within 30 seconds. Without the presence of perchlorates, the bacteria succumbed in about a minute.
This unfortunate discovery shows that if there is life on Mars, it is likely to be hiding far, far below the planet's surface.
"Our observations show that the surface of present-day Mars is very damaging to cells, caused by a toxic cocktail of oxidants, iron oxides, perchlorates and UV radiation," the authors conclude in the journal.Scientific Reports.
ButWe can still get a positive side out of it all. If the Martian soil kills terrestrial microbes upon contact, it means that there is less chance that our missions to Mars could contaminate the neighboring planet.
Reference: Perchlorates on Mars enhance the bacteriocidal effects of UV light. Scientific Reports doi: 10.1038 / s41598-017-04910-3