The Perseverance rover has found an overabundance of organic molecules on Mars, along with other materials, making the dry delta it is currently exploring ripe for searching for potential signs of ancient life.
Large concentrations of complex organic molecules
This new discovery of organic molecules in March took place while Perseverance explored a rocky outcrop located in the jezero crater. Collected with the help of its robotic arm, some of these layered sedimentary rock samples contained materials that had most likely been transported hundreds of kilometers away by one of the many rivers that dotted the surface of the Red Planet billions of years ago. years. .
” The goal was to search for areas similar to those on Earth that harbor signs of ancient life. “, explains Thomas Zurbuchen, chief scientist at NASA. ” We chose to explore Jezero Crater because we thought it was more likely to return scientifically qualitative samples, and now we know we’ve sent Perseverance to the right place.. »
These sedimentary rocks contain complex organic molecules called aromatics, as well as clays and sulfate minerals, which can be produced when water interacts with rocks. Although none of these materials is a clear sign of life, known as a biosignature, their presence in 12 of the samples collected by Perseverance as part of its mission that began in September 2021 has important implications.
” This implies a strong potential for the preservation of biosignatures. “, details David Shuster, from the University of California at Berkeley. ” If these were present nearby when the rock was formed, this is precisely the type of material that will preserve them.. »
“We’re seeing more and more concentrations as we go up the delta”
It also turns out that the prevalence of organic matter has steadily increased throughout Perseverance’s journey through Jezero Crater. “ In this ‘treasure hunt’ for potential signs of life on another planet, organic matter is a clue says Sunanda Sharma of NASA’s Jet Propulsion Laboratory. ” We observe increasingly important concentrations as we ascend through the delta. »
Although organic matter has been discovered in sedimentary rocks that are known to preserve fossils of ancient organisms here on Earth, the instruments carried by Perseverance, however advanced, will not detect their possible Martian counterparts.
We will have to wait at least 2033, and the end of the mission. Mars sample returnso that researchers can study them directly and confirm the presence (or absence) of traces of ancient life.