A group of scientists has developed an innovative method based on artificial intelligence (AI) to detect signs of past or present life on Mars and other planets. The method, described in the journal “Proceedings of the National Academy of Sciences,” uses AI to distinguish between modern and ancient biological samples, as well as abiotic samples, with 90% accuracy.
The lead author, Jim Cleaves from the Earth and Planets Laboratory at the Carnegie Institution for Science in Washington, DC, emphasized the importance of this research. He pointed out that the findings have three main implications. Firstly, biochemistry differs from abiotic organic chemistry at a fundamental level. Secondly, by studying samples from Mars and ancient Earth, we can determine if they were ever alive. Lastly, this method has the potential to differentiate alternative biospheres from the Earth’s biosphere, which could have significant implications for future astrobiological missions.
Unlike conventional methods that rely on identifying specific molecules or compounds, the researchers demonstrated that AI can detect subtle differences in the molecular patterns of a sample. They used gas chromatography pyrolysis analysis to separate and identify the components, followed by mass spectrometry to determine molecular weights. The AI was trained using molecular analysis data from 134 known abiotic or biotic carbonaceous samples.
The AI successfully identified samples from living organisms, such as shells, teeth, bones, insects, leaves, rice, human hair, and preserved cells in fine-grained rocks. It also distinguished between ancient life remnants modified by geological processes (such as coal, oil, amber, and carbon-rich fossils) and abiotic samples, such as laboratory chemicals and carbon-rich meteorites.
Previously, it had been challenging to determine the origin of many ancient carbon samples because organic molecules, whether biotic or abiotic, tend to degrade over time. However, using this new AI-based method, signs of biology have been detected in some cases that have been preserved for hundreds of millions of years.
Dr. Robert Hazen, also from the laboratory, emphasized that these findings open the possibility of finding life forms on other planets or biospheres, even if they are very different from life as we know it on Earth. Furthermore, if signs of life are discovered elsewhere, this method can help determine if life on Earth and other planets have a common or different origin.
This research represents a significant breakthrough in the field of astrobiology and provides exciting possibilities for future missions that explore the presence of life beyond Earth.
– Article in the journal “Proceedings of the National Academy of Sciences” (PNAS)