21-EPN-FT1-008: Detection of Isotopic Biosignatures in Antarctica Subfossils – Implication for the Search of Life on Mars
Visit by Alessia Cassaro of the University of Tuscia (Italy) to TA2 Facility 16 – Carbon-14 Dating AMS Laboratory.
Dates of visit: 12-16 December 2023.
Report Summary: Victoria Land, Timber Peak (Northern Victoria Land) and Mt. Fleming (Southern Victoria Land) localities are considered as a good terrestrial analogue of the Martian surface. These localities are characterized by harsher climatic conditions and endolithic microbial communities represent a borderline lifestyle. The survival of these communities depends on a delicate balance of biological, geological and climatic factors. Any unfavourable change of this equilibrium may result in the death of the community and the alteration of the rock, potentially followed by the formation of trace fossils. This process could be similar to that experienced by hypothetical life-forms on early Mars, or reflect a decay mechanism in Mars history.
Detecting traces of extant or recently extinct life is one main goals of the upcoming NASA Mars 2020 and the near future ESA ExoMars missions. In this context, the characterisation of Antarctica subfossil rocks, may be used in support of space missions. To date, only morphological descriptions (culture-dependent method) and microanalytical techniques (SEM-EDX, confocal Raman and Infrared and EPR spectroscopies) have already been performed on these samples. In this context, the main aim of this Europlanet project will be the characterisation of carbon isotopes (13C/12C) composition on samples from Timber Peak and Mt. Fleming localities. Control samples will be compared with irradiated samples (117 kGy of gamma rays) in order to i) determine the sources of organic matter and ii) understand if cosmic-ray exposure, similar to those reported on the surface of Mars for 1.5 millions of years and 13 millions of years at 2 meters beneath the surface, may altered carbon isotopic composition.
