Organic molecules of unprecedented size discovered on Mars
by CNRS
The longest organic molecules identified to date on Mars have recently been detected by scientists from the CNRS, together with their colleagues from France, the U.S., Mexico, and Spain. These long carbon chains, containing up to 12 consecutive carbon atoms, could exhibit features similar to the fatty acids produced on Earth by biological activity.
The lack of geological activity and the cold, arid climate on Mars have helped preserve this invaluable organic matter in a clay-rich sample for the past 3.7 billion years. It therefore dates from the period during which life first emerged on Earth. These findings are due to be published on March 24, 2025, in the Proceedings of the National Academy of Sciences.
The Significance of Organic Molecules on Mars
Understanding the presence of organic molecules on Mars is crucial for several reasons:
- **Potential for Past Life**: The discovery of organic molecules suggests that Mars may have had conditions suitable for life in its past.
- **Chemical Complexity**: The length and structure of the carbon chains indicate a level of chemical complexity that opens up new avenues for astrobiological research.
- **Insights into Earth's History**: Studying these molecules could provide insights into the early conditions on Earth when life was just beginning.
Methodology Behind the Discovery
The organic molecules were identified using the Sample Analysis at Mars (SAM) instrument aboard NASA's Curiosity rover. This sophisticated gadget has been actively analyzing Martian samples for several years now.
| Instrument | Purpose | Findings |
|---|---|---|
| SAM (Sample Analysis at Mars) | Analyze Martian soil and rock samples to identify organic compounds | Detected long-chain hydrocarbons and other complex organic molecules |
Future Missions and Research Goals
The identification of these organic molecules informs future exploratory missions planned by the European Space Agency (ESA) and NASA:
- ESA's upcoming ExoMars mission is set to launch in 2028 and will aim to further explore the Martian subsurface, searching for signs of past life.
- The joint NASA-ESA Mars Sample Return mission planned for the 2030s will seek to bring Martian samples back to Earth for comprehensive analysis.
Related Studies of Organic Molecules Beyond Mars
Similar research is expanding beyond Mars to other celestial bodies, driven by the pursuit of understanding life's origins:
| Celestial Body | Research Focus | Current Status |
|---|---|---|
| Europa (Moon of Jupiter) | Potential subsurface ocean and its chemical compositions | Current missions are in planning stages for future exploration |
| Titan (Moon of Saturn) | Organic-rich atmosphere and liquid methane lakes | NASA's Dragonfly mission aims for Titan exploration in 2034 |
Conclusion
In summary, the discovery of long organic molecules on Mars represents not only a monumental scientific achievement but also a pivotal moment in our quest to understand the possibility of life beyond Earth. As we look to the near future, the findings will undoubtedly steer the direction of subsequent research, shaping our comprehension of astrobiology in the broader context of space exploration.
More information: Caroline Freissinet, Long-chain alkanes preserved in a Martian mudstone, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2420580122.
