According to new research, acidic fluids could have long ago destroyed evidence of past biological life on the Red Planet. This would explain why it was so difficult to find evidence of ancient life on Mars.
European researchers say that new experiments, detailed in a recent paper in the journal Nature Scientific Reports, show that such fluids could put serious constraints on the possibility of finding evidence of early life on the planet’s surface.
Researchers have long targeted Martian clays to collect samples, as they could protect any possible organic material inside.
“We know that acidic fluids have flowed on the surface of Mars in the past, altering clays and their ability to protect organic elements,” said Alberto Fairén, a scientist in the Department of Astronomy at the College of Arts and Sciences at Cornell and author of the paper. .
Researchers say that the internal structure of clay is organized into layers, where evidence of biological life – such as lipids, nucleic acids, peptides and other biopolymers – can become captive and well preserved.
The acidic fluids would have completely erased the traces of life on Mars
In a series of experiments, the team simulated the conditions of the Martian surface inside a laboratory. Their purpose was to preserve a specific amino acid, called glycine, in clay samples. These clay samples have been previously exposed to acidic fluids, simulating planetary conditions.
“We used glycine because it could degrade quickly in the planet’s environmental conditions,” Fairén said. “He is a perfect informant to tell us what is happening in our experiments,” he added. Then, after the administration of ultraviolet radiation, the glycine molecules degraded inside the clays.
“When clays are exposed to acidic fluids, the layers collapse and the organic matter cannot be preserved. They are simply destroyed, ”Fairén explained. “Our results in this paper explain why searching for organic compounds on Mars is so difficult,” he added.