When we send spacecraft to Mars, we have to heavily sterilize them in order to not accidentally take Earth life with us. After all, we don’t want to contaminate the surface of the Red Planet with our own life, and possibly make a false detection in the future.
However, a new study poses an intriguing idea. Published in Scientific Reports, Jennifer Wadsworth and Charles Cockell from the University of Edinburgh say the surface of Mars basically wouldn’t allow any cells to survive. It suggests that contamination by spacecraft may not be that big an issue.
In their study, they found that a compound called perchlorate could be activated on the surface of Mars by sunlight. This is important, because this compound is lethal to bacteria when it’s activated, and it’s abundant on Mars. Before, it was only thought to be activated by heat – and as Mars is very cold, that didn’t seem to be a problem.
“We might have previously thought it wouldn’t be possible to activate it under Martian conditions,” Wadsworth told IFLScience. “If we want to find life on Mars, we have to take this into consideration.”
They made their findings by simulating the Martian environment in a laboratory. Using an anaerobic chamber, which has no oxygen, they recreated the wavelengths of light on the surface of Mars. They then monitored the effect of perchlorates in this condition on a common contaminant found on spacecraft, Bacillus subtilis.
In conditions similar to Martian soil, the cells died within a matter of minutes when the perchlorates were activated. This heavily suggests that the surface of Mars is even more toxic to life than we thought.