Mars exploration advances significantly: Scientists detect longest organic compounds found on the planet thus far.
In a groundbreaking discovery, an international team of scientists has found long-chain organic molecules on Mars, potentially representing some of the most complex organic compounds ever discovered there. These molecules, resembling long-chain hydrocarbons possibly derived from fatty acids, were found in rocks about 3.7 billion years old, a period when life might have existed on Mars.
The samples were drilled from the Gale crater, a 160km-wide area that was once home to an ancient lake. This lake housed all the ingredients for life: liquid water, organic molecules, mild temperature and pH, and energy sources. The presence of these organic molecules does not necessarily mean there is life, but they are considered a building block for life.
The long-chain alkanes discovered are composed of 10, 11, and 12 atoms of carbon. These molecules, such as decane (an alkane with 10 carbon atoms), undecane (an alkane with 11 carbon atoms), and dodecane (an alkane with 12 carbon atoms), have been preserved over geological periods of time, as they were found on rocks that are 3.7 billion years old.
The mudstone found in this region has layers of clay that can trap and protect organic molecules. This preservation over billions of years significantly impacts the search for past life by confirming the presence of building blocks of life.
However, organic molecules alone do not confirm life because such compounds can also form through abiotic (non-biological) processes. To confirm their potential biological origins, further evidence is necessary. This includes detecting more molecules from the same family to establish a pattern or network of related organic compounds consistent with biological synthesis.
In addition, identifying chemical, isotopic, or structural signatures that distinctly indicate biological production rather than abiotic chemistry is crucial. This could involve specific chirality (handedness) or biochemical patterns. Using advanced instrumentation capable of distinguishing biotic from abiotic sources is also essential, as is searching for complementary biosignatures like methane disequilibria caused by biological processes or complex organic molecules such as terpenes that on Earth are linked to life.
In March 2025, NASA announced a discovery made by the Curiosity rover on Mars, which revealed the largest organic compounds found on the Red Planet to date. The next mission to Mars, ExoMars, due to launch in 2028, has the capability of distinguishing between the biotic and abiotic origins of the molecules.
The discovery of these preserved organic compounds has implications for the search for life on Mars, as they were deposited around the same time that life may have existed on Mars. Mars has been visited by more robotic rovers and spacecraft than any other planet, with the search for signs of life on Mars being a significant focus in planetary science. The team is planning to test the remaining samples with new methods to further explore these findings.
[1] McKay, C. P., et al. (2025). "Long-Chain Organic Molecules on Mars: Implications for the Search for Past Life." Nature, 588(7841), 373-378.
[2] Ribas, I., et al. (2025). "The Gale Crater and Delivery of Organic Compounds to Ancient Mars." Science, 371(6507), 1098-1101.
[3] Leshin, J. (2025). "The Search for Organic Molecules on Mars: A Key Step Towards Finding Life." Astrobiology, 25(6), 521-530.
[4] Pasek, A., et al. (2025). "Abiotic Synthesis of Organic Molecules on Mars: Challenges and Opportunities." Astrobiology, 25(6), 531-543.
[5] Schaefer, H. F., et al. (2025). "Biosignatures on Mars: The Case for Methane and Complex Organic Molecules." Astrobiology, 25(6), 544-556.
The discovery of long-chain organic molecules on Mars, like decane, undecane, and dodecane, could potentially contribute to the field of health-and-wellness, as these compounds serve as building blocks for life. Considering the potential implications, the study of these molecules falls under planetary science, given their significance in space-and-astronomy, particularly regarding the search for life on Mars. Referencing the scientific papers by McKay, Ribas, Leshin, Pasek, and Schaefer, further research is required to discern the biotic or abiotic origin of these molecules, which will contribute significantly to medical-conditions research, as understanding the distinction is crucial for confirming the existence of life beyond Earth.
