In a significant finding, NASA’s Perseverance rover has detected complex macromolecular carbon sitting right on the surface of a Martian rock. This discovery was made at an outcrop on the edge of an ancient river channel named Neretva Vallis and is considered one of the shallowest detections of organic matter on the Martian surface to date.
The detection was made using SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals), a UV Raman spectrometer fitted on Perseverance’s robotic arm. The instrument fires a deep-ultraviolet laser at a target and reads the light that bounces back, enabling scientists to identify specific molecular bonds.
The team pointed SHERLOC at four targets at Bright Angel, one of which was an ordinary rock used as a control. Three of the remaining targets returned a spectroscopic signature of macromolecular carbon, indicating the presence of a tangled, cross-linked network of mostly reduced carbon atoms that is resistant to chemical and thermal breakdown.
The material found on Martian rocks roughly matches terrestrial kerogen, but the researchers are cautious not to imply a biological origin. Instead, they use the term ‘macromolecular carbon’ to indicate that its source could be either biotic or abiotic.
To confirm the finding, the team checked for potential sources of contamination and ruled out light bouncing off SHERLOC’s own fused-silica front window as well as contamination from Earth. The researchers also analyzed the chemistry of the material nearest to the Martian macromolecular carbon and found evidence that it may have occurred during at least two different events over geologic time.
The discovery raises questions about the origin of the complex carbon on Mars, with some scientists suggesting that it could be a remnant of ancient Martian life. However, more analysis is needed to determine its true nature. The Perseverance rover’s science payload was not designed to distinguish between abiotic and biotic processes, but rather to identify compelling rocks for possible return to Earth.
### Background on SHERLOC
SHERLOC uses a UV Raman spectrometer to analyze the molecular composition of Martian samples. This technology is particularly useful in detecting organic matter, as it can penetrate through layers of dust and debris to reveal underlying chemical signatures.
### Implications for Astrobiology Research
The discovery of complex carbon on Mars has significant implications for astrobiology research. While the origin of this material is still unclear, its presence suggests that the Martian surface may have once supported life or at least had conditions suitable for it.
### Future Research Directions
To further understand the nature and origin of the complex carbon on Mars, researchers will need to conduct more analysis using a variety of techniques. This could include studying the chemistry of the surrounding environment, analyzing the material’s structure, and comparing its properties with those found in terrestrial samples.
Source: Original article