NASA recently announced that the Martian rover Perseverance discovered a potential biosignature, a substance or structure that might have a biological origin.
Dotting the side of a rock formation nicknamed Cheyava Falls is a rock and mineral formation that looks like the spots of a leopard. The Perseverance team used the rover to take a sample, which they dubbed Sapphire Canyon, and after a year of investigation, determined it contains potential biosignatures, according to a paper published Wednesday in the journal Nature.
Ashely Murphy is a Planetary Science Institute postdoctoral research scientist and a science collaborator on an instrument onboard the Perseverance rover called SHERLOC, short for Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals, a spectrometer on the robotic arm of the rover. Murphy works on the mission’s surface operations, where she assisted with the selection of SHERLOC targets on Martian rocks, including those where the sample was found. She assisted with the SHERLOC data collection, analyses, interpretation and discussion of the new paper.
“As a planetary scientist, the results published in this recent paper are very exciting,” Murphy said. “Cheyava Falls, in particular, is a unique rock that can help shed light on complex chemical reactions that took place on ancient Mars.”
Perseverance came across Cheyava Falls while exploring the Bright Angel formation, a set of rocky outcrops on the northern and southern edges of Neretva Vallis, an ancient river valley measuring a quarter-mile wide that was carved by water rushing into Jezero Crater long ago, according to a NASA Jet Propulsion Laboratory statement. The rover’s science instruments found that the formation’s sedimentary rocks are composed of clay and silt, which, on Earth, are excellent preservers of past microbial life. They are also rich in organic carbon, sulfur, oxidized iron (rust) and phosphorous.
“The discovery of reduced iron phosphates and sulfides associated with organic carbon in sedimentary rocks on Mars suggests complex geochemical reactions, which have implications for our understanding of abiotic, and potentially prebiotic or biotic, chemical processes on ancient Mars,” Murphy said. “Additionally, these findings also mark the first discovery of organic-rich mudstones outside of Gale crater, which indicates that the availability of organics may have been widespread across the planet billions of years ago, and this is important for our understanding of the extent and diversity of Martian surface processes and how this relates to habitability and potential life detection.”
While Perseverance was designed to explore Jezero crater for samples containing potential biosignatures, the finding requires more data and analysis – from Earth-based laboratories if a sample can someday be returned – before a conclusion can be reached about the absence or presence of life.
