Commonwealth _ NASA’s Perseverance rover has made a significant discovery on Mars, uncovering what may be the first hint of ancient microbial life on the Red Planet. This breakthrough was announced following the analysis of a sample retrieved from a reddish rock, named Cheyava Falls, after a feature at the Grand Canyon. This sample, collected on July 21, is the most promising finding Perseverance has encountered in its search for signs of life on Mars.
The rock in question is notable for containing organic molecules, which are fundamental building blocks of life. Ken Farley, a project scientist at Caltech, reported this development on July 25 during the 10th International Conference on Mars in Pasadena. While this discovery does not confirm the presence of life, it represents the most compelling evidence Perseverance has gathered to date.
Before this, the Curiosity rover had detected organic molecules in the Gale Crater back in 2014, but the identification of organic materials has been a challenging task for Perseverance since its landing in Jezero Crater, an ancient dried-up lake, in 2021. The discovery of these organic molecules in the sample from Cheyava Falls is a significant advancement in the search for Martian life.
The rock’s surface features intriguing white spots with black rims, which Stack Morgan, Perseverance’s deputy project scientist at NASA’s Jet Propulsion Lab in Pasadena, likened to “tricolored leopard spots.” These spots were analyzed using instruments designed to identify their chemical composition. The analysis revealed that the rims of these spots contain iron phosphate molecules. On Earth, similar chemical structures and textures are often associated with ancient microbial life, as the chemical reactions responsible for creating these rings can serve as an energy source for microbes.
However, Stack Morgan cautioned that while the presence of these features on Mars might suggest a biological origin, they do not necessarily confirm the existence of life. “They don’t require life, of course, and that’s an important caveat,” she explained. The resemblance to terrestrial microbial formations does, however, leave open the possibility that these Martian features could be of biological origin.
The rock also contains white veins of calcium sulfate, which are filled with millimeter-sized crystals of olivine, a mineral that forms from magma. The combination of these volcanic features with the white spots creates a complex picture of the rock’s formation, presenting a challenge for scientists trying to determine its history. The conflicting indicators of volcanic and biological origins make it difficult to ascertain the conditions under which the rock formed and whether it could have supported life.
Paul Byrne, a planetary scientist at Washington University in St. Louis, emphasized the need for caution in interpreting the findings. “Could this truly be a biosignature? Yes. And if it is, then it is the kind of society-altering discovery that the discovery of truly extraterrestrial life would be,” Byrne said. Nonetheless, he also noted that it is possible the spots could be the result of non-biological processes, such as water-rock chemistry, and that the discovery may simply be an interesting example of these processes.
To definitively determine whether the features on Cheyava Falls are indicative of ancient life, the rock sample will need to be returned to Earth. A key part of Perseverance’s mission is to collect and store samples from intriguing rocks like this one, which will eventually be retrieved by a future spacecraft. Studying these samples in advanced laboratories on Earth will provide a more comprehensive analysis than the rover’s instruments alone can offer. As Stack Morgan noted, Perseverance has already conducted extensive analyses of the rock, but conclusive answers will require further study once the samples are returned.
