Main points
- The researchers propose using statistical analysis of chemical patterns in samples to detect possible signs of life on Mars instead of looking for individual biomarkers.
- The new method could be applied in future NASA missions, such as Dragonfly, to analyze organic molecules on Saturn's moon Titan.
Scientists have proposed a simple way to search for alien life without directly detecting organisms / Unsplash / ThisisEngineering
The search for signs of life beyond Earth could gain a surprisingly simple tool. A new study suggests analyzing not individual molecules but hidden chemical patterns that could indicate the biological origin of samples.
Despite decades of exploration of Mars , the question of whether life once existed there remains an open question. Data collected by the Curiosity and Perseverance rovers in recent years has provided some promising clues, but definitive proof is still lacking, writes Mashable .
Can alien life be found through a chemical “fingerprint”?
In particular, Curiosity, exploring Gale Crater , has found complex carbon compounds in Martian rock samples. Meanwhile, Perseverance, operating in Jezero Crater about 3,700 kilometers away, has found fossilized material that could potentially be the product of ancient microorganisms.
However, the key problem is that these organic molecules may not only be the result of biological processes. Such structures can also form as a result of the interaction of water with minerals or other geochemical reactions. This is why even the most advanced instruments on board Mars rovers cannot definitively confirm the origin of such finds.
Last year, Nicky Fox , NASA's associate administrator for science, said: “This discovery by our incredible Perseverance rover is the closest we've ever come to detecting ancient life on Mars.”
A new approach to an old problem
A group of researchers proposed an alternative method, the results of which were published in the journal Nature Astronomy.
Its essence lies in the analysis not of individual biomarkers , but of the overall structure of the chemical composition of the sample. Instead of trying to find a specific “molecule of life”, scientists propose to evaluate the statistical distribution of organic compounds and identify patterns characteristic of biological systems.
Lead author of the study , Gideon Yoffe of the Weizmann Institute of Science, explained: “Astrobiology is essentially a forensic science. We try to reconstruct processes from incomplete traces, often with very limited data collected during extremely expensive and rare missions.”
How is life different from non-living chemistry?
To test the hypothesis, the team compared a wide range of materials: biological samples, fossil remains, ocean sediments, meteorites, asteroid material, and laboratory simulations of early Earth and space chemistry.
Particular attention was paid to amino acids – the building blocks of proteins – and fatty acids that form cell membranes.
The results showed a clear statistical boundary between living and non-living systems. Biological samples contained a broader, more balanced and ordered set of amino acids. This is because living cells actively synthesize a variety of compounds to perform specific functions.
In contrast, abiotic samples showed a simpler and less diverse composition, dominated by a few basic molecules. Interestingly, contaminated meteorites shifted closer to the “biological” group, indicating a noticeable impact of even minor biological interference on the chemical pattern.
Can cosmic radiation erase traces of life?
This question was one of the key ones. The researchers simulated the conditions on the surface ice layers of Europa, a moon of Jupiter that is considered one of the most promising candidates for the search for extraterrestrial life.
According to the journal Nature , experiments showed that even after significant radiation damage , the statistical “signature” of biological origin was often preserved. At the same time, samples that were subjected to intense heating, prolonged aging or powerful irradiation gradually lost molecular diversity and began to resemble non-living matter.
How will this help future NASA missions?
According to co-author Fabian Klenner of the University of California, Riverside, modern Mars rovers are potentially already capable of using this method – provided they find a sample rich enough in organics. Even more promising is the Dragonfly mission, which NASA plans to send to Saturn's moon Titan in the mid-2030s.
The instrument will have a mass spectrometer capable of analyzing organic molecules with high precision. Klenner said: ” Dragonfly is a particularly interesting case. If it can distinguish between organic molecules and their relative concentrations, I would really like to see our approach applied to that data.”
The new statistical method is unlikely to be a universal answer to the question of the existence of extraterrestrial life. But it could become an important tool that can help significantly narrow the room for doubt where traditional methods leave too much uncertainty.