Organic Molecules Discovered on Mars by Curiosity Rover

Scientists from CNRS and international colleagues have identified large organic molecules on Mars, with up to 12 carbon atoms, resembling Earth’s fatty acids. Mars’ cold, arid conditions preserved These molecules in a clay sample for 3.7 billion years. The discovery was made using SAM, an instrument on NASA’s Curiosity rover in Gale Crater, and will be published in PNAS on March 24, 2025. This finding highlights the potential for future missions like ExoMars and Mars Sample Return to explore signs of life-like chemistry beyond Earth.

Organic Molecules of Unprecedented Size Discovered on Mars

Scientists have identified organic molecules of unprecedented size on Mars, marking a significant advancement in our understanding of Martian chemistry. These molecules, containing up to 12 consecutive carbon atoms, resemble Earth’s fatty acids, which are crucial for life. The discovery was made using SAM (Sample Analysis at Mars), an instrument aboard NASA’s Curiosity rover, and the findings will be published in PNAS on March 24, 2025.

The organic molecules were preserved in a clay-rich sample, protected by Mars’ cold, arid environment for approximately 3.7 billion years. This age aligns with the period when life first emerged on Earth, suggesting intriguing parallels in the chemical evolution of both planets.

This discovery underscores the potential for future missions to explore complex chemistry beyond Mars. Upcoming endeavors like ESA’s ExoMars and NASA-ESA’s Mars Sample Return mission aim to build on these findings. Additionally, plans are underway to develop similar instruments for missions such as Dragonfly to Titan, expanding our exploration of organic molecules in the Solar System.

The detection of “organic molecules on Mars” not only highlights Mars’ potential for past or present life but also sets the stage for broader astrobiological investigations across the cosmos.

Preservation of Organic Matter in Martian Conditions

Preserving organic molecules in Martian conditions is a remarkable achievement that provides critical insights into the planet’s chemical history. The cold, arid climate of Mars has played a pivotal role in safeguarding these long-chain alkanes, which have been preserved in a clay-rich sample for approximately 3.7 billion years. This timeframe corresponds to the era when life first emerged on Earth, suggesting Mars may have harboured similar chemical precursors.

The stability of these organic molecules is attributed to the lack of significant geological activity on Mars, which has minimized environmental disruptions that could degrade such compounds. The clay-rich environment further enhances preservation by acting as a protective medium, preventing degradation and ensuring the integrity of the organic material over vast timescales.

This discovery highlights the potential for past or present life on Mars and underscores the importance of studying ancient organic matter in extraterrestrial environments. By understanding how these molecules have been preserved, scientists can better interpret the chemical signatures of other planetary bodies and refine their search for biosignatures in the Solar System.

Future Missions to Explore Complex Chemistry Beyond Earth

Future missions aim to build on the discovery of long-chain alkanes on Mars by exploring complex chemistry in other parts of the Solar System. ESA’s ExoMars mission, set to launch in 2028, will search for additional organic compounds and biosignatures on the Martian surface. Similarly, NASA-ESA’s Mars Sample Return mission in the 2030s plans to retrieve samples from Mars for detailed analysis back on Earth, potentially revealing more about the planet’s chemical history.

The success of SAM (Sample Analysis at Mars) on the Curiosity rover has demonstrated the value of advanced analytical tools in detecting and characterizing organic molecules. This technology will likely be adapted for future missions, such as the Dragonfly mission to Saturn’s moon Titan. By studying organic compounds in Titan’s environment, scientists hope to gain insights into the conditions that may have led to the emergence of life on Earth.

These missions highlight the importance of continued exploration and sample return efforts in understanding the distribution and stability of organic molecules across the Solar System. Each endeavour contributes critical data to the broader quest of identifying potential biosignatures and unravelling the origins of life beyond Earth.