As such, the perchlorates found on Mars by Nasa's Phoenix Lander in 2008 were assumed to be inactive, as the surface of the planet is so cold. This hypothesis was backed up by the observation that low temperatures, which slow down chemical reactions, extended the lifespan of the bacteria in the perchlorates but still resulted in them dying. And researchers have been optimistic that their presence could support bacterial life on Mars.
Wadsworth: We irradiated bacteria with UV in the presence of perchlorate at Martian concentrations. Next, researchers mixed magnesium perchlorate with the bacteria and exposed it to the same level of radiation. The scientists have first put the bacteria in a water solution of the perchlorate and then exposed it to radiation the same as it would be exposed if it were on Mars. Science fiction authors have been imagining life on Mars for generations, and scientists have been looking for signs of life on the red planet for decades. "I can't speak for life in the past", co-author Jennifer Wadsworth tells Sample. "As far as present life, it doesn't rule it out but probably means we should look for life underground where it's shielded from the harsh radiation environment on the surface". However, a recent study suggests that the surface of the #Red Planet is more uninhabitable than previously thought.
Researchers have had their suspicions over whether microorganisms can actually survive on the surface of the Red Planet, and now lab tests are spelling doom for any potential little green bacteria. "This should greatly reduce planetary protection concerns as well as any concerns about infection of astronauts", he said. They think this happens because the UV light breaks apart the perchlorate molecules into more reactive ions that wreak havoc on living cells.
In 2020, the European Space Agency plans to send a rover to the red planet on a mission to search for alien life. This makes the surface "microbe-killers".
"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", the researchers conclude. Although we have our own problems with perchlorate here on Earth - too much of it can mess with the thyroid gland - the new paper suggests that perchlorate is particularly nasty on Mars.