Abstract EANA2024-82 |
Stability of amino acids and fatty acids under UV radiation in Marian simulated environment.
While there is evidence for the presence of organic molecules on Mars, their detection and identification remains a challenge due to several factors that can affect their preservation and detectability. To improve this, the Perseverance and the Rosalind Franklin rovers are both equipped with near-infrared (NIR) vibrational spectrosctrometers1. However, the wide variety of environmental factors and molecule-mineral interactions can make interpretation of IR spectral data very complicated. Vibrational spectroscopy relies on the vibrational modes of the bonds between the functional groups, and if these bonds are affected as a result of the interactions with the mineral, the vibrational bands corresponding to the affected functional groups will undergo significant changes2. In addition to the analytical technique and the complexity of interpreting the data, the thin Martian atmosphere, which allows more ionising radiation (e.g. UV) to reach the surface than on Earth, is a problem for the stability of organic compounds. It is thought that the most suitable conditions for the preservation of organic compounds may be found in the subsurface, protected from radiation. At the surface, some preservation of organic compounds can be achieved in the presence of photoprotective minerals3. In this sense, and to maximise the chances of detecting organic compounds on Mars, it is crucial to study the effect of UV radiation on organic compounds adsorbed in minerals that can represent Martian soils. In this work, L-histidine and undecanoic acid were adsorbed on saponite and vermiculite and analysed by infrared spectroscopy to aid the identification of biomolecules by Mars missions. In addition, the UV degradation of the pure molecules and those adsorbed on saponite and vermiculite will be studied in order to suggest the best preservation method.
Acknowledgements: This work has been financially supported through the PAMMAT project (Grant No. PID2022-142750OB-I00), funded by the Spanish AEI, MCINN and the European Regional Development Fund and through the ASI/INAF agreement 2023-3-HH.0.
References: [1] Vago, J. L. et al. (2017) Astrobiology, 17, 471–510. [2] . Fornaro, T. et al. (2020) Front. Astron. Space Sci., 7, 539289. [3] Fornaro, T. et al. (2018) Life 8 (4), 56.