NASA confirms organic carbon in Martian Bright Angel rocks
A study published in Science Advances reports that the Perseverance rover detected macromolecular carbon in two mudstone samples from the Bright Angel formation, marking the shallowest organic detection on Mars.
NASA's Perseverance rover has confirmed the presence of organic carbon in two mudstone rocks from the Bright Angel formation in Jezero crater, according to a paper in Science Advances. Using the SHERLOC instrument, researchers performed Raman spectroscopy on the rocks and identified macromolecular carbon (MMC) associated with fine-grained sediments, carbonate and sulfate minerals.
The MMC was found only a few microns below the surface, the shallowest detection of such material on Mars to date. Researchers noted that the Martian surface environment—characterized by radiation and chemical oxidants—typically degrades organics, suggesting that the detected MMC either resists degradation or is protected by surrounding minerals such as clays or iron-rich soil.
The discovery was made more than 2,000 miles from previous organic detections by the Curiosity rover in Gale crater, indicating that organic compounds may have been more widely distributed in ancient Martian lakes and rivers. While the Perseverance rover lacks the equipment to determine whether the MMC is of biological origin, scientists say that analysis of returned samples on Earth will be required to resolve its source.
"While the specific formation mechanism of the MMC detected in the Bright Angel mudstones remains unknown, this is still one of the most exciting findings to date," said Ashley Murphy, a postdoctoral researcher at the Planetary Science Institute.
"The Martian surface environment includes radiation and chemical oxidants that are destructive to organics, and terrestrial laboratory simulations have shown that the survival time of organics in Martian-like conditions—especially at or near the surface—depends on factors such as the type of organic molecule and the surrounding minerals," Murphy added.
"It is encouraging for Martian habitability," Murphy said, noting that the findings suggest organics may have been more broadly present in ancient Martian water bodies.
"Perseverance was built with the goal of detecting potential biosignatures such as those found in the Cheyava Falls rock, making this a resounding win for Mars science," Murphy concluded.
Future work will involve returning samples to Earth for higher-resolution mineral and organic analyses to better understand the origin of the MMC and its implications for Martian habitability.