Evrim Yazgin
Cosmos science journalist
NASA’s Perseverance rover has found evidence of diversity among the organic molecules on Mars.
Organic molecules are the key building blocks of life on Earth.
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The findings, published in Nature, suggest a more complex geochemical cycle than previously thought existed on the planet’s distant past.
On Mars organic molecules are not new. They are compounds made up of carbon and hydrogen. Several different types of organic molecule have already been found in Martian meteorites on Earth as well as the Gale crater on the surface of the Red Planet.
“Evaluating the diversity and detectability of organic matter elsewhere on Mars is important for understanding the extent and diversity of Martian surface processes and the potential availability of carbon sources,” the authors write.
The Jezero Crater is the site of an ancient lake basin which has been earmarked as a place with high potential for evidence of the existence of life in Mars’s past.
All ten targets from Máaz and Séítah, two formations on the crater floor, showed the presence of organic molecules.
Organic compounds were more concentrated on Máaz than Séítah, with both formations showing a diverse array of hydrocarbon molecules. The diversity of compounds found in the samples may provide insight into the origin of the organic matter.
The authors suggest that organic molecules found in the formations may have been deposited by water or synthesised through volcanic materials.
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“These potential organic molecules are largely found within minerals linked to aqueous processes, indicating that these processes may have had a key role in organic synthesis, transport or preservation,” they write.
Perseverance’s Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument was used to detect the organic molecules in the Jezero Crater where the rover landed in 2021.
SHERLOC is the first tool to give fine-scale mapping and analysis of organic molecules and minerals on the Martian surface. It uses Raman spectroscopy, which uses light scattered off molecules at different frequencies to accurately determine which compounds exist in a sample, and their relative abundance.