Scientists from CNRS, together with colleagues from France, Spain, the US, and Mexico, have uncovered the longest organic molecules on Mars to date, according to a study published in PNAS.
These long molecules contain up to 12 consecutive carbon atoms, and the researchers expect them to exhibit properties similar to those of fatty acids present in animal and vegetable fats and oils. The cold and dry environment combined with a lack of geological activity have helped preserve this organic matter in a clay sample for the past 3.7 billion years. This means it dates from the time when life first started to emerge on the planet Earth.
The samples were collected using SAM. Called Sample Analysis at Mars, SAM is a small laboratory located inside Curiosity. It can conduct analysis using a gas chromatograph and a mass spectrometer to identify molecules in collected samples.
This is just one of the instruments onboard NASA’s Curiosity rover, which has been studying the Gale crater on Mars since 2012. This success is just the beginning of many future interplanetary science missions in search of signs of complex chemistry.
In fact, this will be one of the ambitious goals of the upcoming mission to Mars, which will be launched in 2028, and of the Mars Sample Return mission in the 2030s. With the long-term aim of exploring further out in the Solar System, this international team is planning to build a device similar to SAM for Dragonfly, the drone that is due to explore the surface of Titan, Saturn’s largest satellite, from 2034 onwards.
Freissinet C, Glavin DP, Archer PD Jr, Teinturier S, et al. Long-chain alkanes preserved in a Martian mudstone. Proc Natl Acad Sci U S A. 2025 Apr;122(13):e2420580122. doi: 10.1073/pnas.2420580122.