The impact of stellar flares and superflares on life: first experiments to reveal the UV surface habitability of exoplanets

ABREVAYA X.C.; OPPEZZO, O.J.; ODERT, P.; LEITZINGER, M.; PATEL, M.; FORTE GIACOBONE, A.F.; HANSLMEIER, A

Conferencia; Habitable Worlds 2021; 2021

The increasing discovery of exoplanets in the last decades has boosted the search for life in the universe, and particularly the studies for the characterization of planetary habitability. Stellar radiation is one of the fundamental factors to be studied in this context, as it can have an influence on the planetary environment and can be a constraint for life through direct or indirect effects. Depending on the atmospheric composition and pressure, UV radiation wavelengths (200-400 nm) can reach the surface of the planets and could be harmful to life. Moreover, it is unknown if UV fluxes from very energetic events as flares and superflares could limit the surface habitability of a planet. Previous studies have analyzed the UV surface environments on exoplanets to study the impact of UV radiation on life, however, this has only been approached partially from a theoretical point of view (i.e. modeling of the biological impact of UV). In a recent interdisciplinary study, we experimentally determined through laboratory experiments and for the first time, the impact that flares and superflares could have on microorganisms. We found out that previous studies underestimated the chances of “life as we know it” to thrive under these conditions. In this talk, I will describe the drawbacks of methodologies used in previous studies, and I will present our latest results about the impact of flares and superflares on potential microbial life in exoplanets aimed to study UV surface habitability. These efforts are part of the EXO-UV program, an international interdisciplinary collaboration that seeks to expand the characterization of UV radiation environments through experimental approaches.