Deletion of evidence
According to a new study, acidic liquids have long destroyed evidence of past biological life in Martian clay – probably explaining why it was so difficult to find evidence of ancient life on the Red Planet.
Cornell and European researchers argue that new experiments detailed in a report published today in Nature magazine Scientific reports, show that such liquids can place severe limitations on the ability to find evidence of early life on the planet ‘s surface.
Researchers have long targeted Martian clays for sampling, as they could protect any possible organic material inside.
“We know that acidic liquids have flowed on the surface of Mars in the past, altering clays and their ability to protect organic matter,”
In a series of experiments, the team simulated the conditions of the Martian surface in a laboratory. Their goal was to preserve a specific amino acid called glycine in clay samples. These clay samples have previously been exposed to acidic liquids simulating planetary conditions.
“We used glycine because it can degrade quickly in the planet’s environment,” Feren said. “The perfect informant is to tell us what happened in our experiments.”
After application of ultraviolet radiation, glycine molecules decompose inside the clays.
“When clays are exposed to acidic liquids, the layers collapse and organic matter cannot be preserved,” Feren said. “They are destroyed.”
“Our results in this article explain why the search for organic compounds on Mars is so difficult,” he added.
READ MORE: The study shows difficulties in finding evidence for life on Mars [Cornell University]
More on Martian life: Evidence of life on Mars found by NASA Rover