Degradation of beta-carotene under mineral thin sections during proton irradiation monitored in situ by Raman spectroscopy

Kurzfassung

Mars is considered as one of the most promising targets in the quest for extraterrestrial life in the Solar system (Cottin et al., 2017; McKay, 1997; Westall et al., 2015). Since the Mariner 4 probe in the 1960’s, many missions have been sent to study the present and ancient environmental conditions at the surface of the Red Planet (Farley et al., 2020; Grotzinger et al., 2012; Klein et al., 1976), documenting liquid water forming rivers, seas and lakes during the Noachian-Early Hesperian period (c.a. 3.5 billion years ago) (Ehlmann et al., 2009; Fassett and Head-III, 2008; Grotzinger et al., 2014; Le Deit et al., 2012; Mangold et al., 2021; Poulet et al., 2005). Locally, the surface of Mars hosted habitable conditions that lasted potentially long enough to allow the emergence and development of primitive microbial life (McKay, 1997; Schulze-Makuch et al., 2008; Westall et al., 2021; Westall et al., 2015). While life could still be active in deep aquifers several hundred meters below the surface (Marais, 2010), its existence at the surface is highly speculative. On the other hand, in the absence of plate tectonics, ancient organo-mineral traces of life dating back from the Noachian could still be present at the surface.