Abstract The search for habitable planets and signatures of extraterrestrial life is one of the most ambitious and consequential projects of our civilization. Observations taken with Kepler, Transiting Exoplanet Survey Satellite (TESS) and the Hubble Space Telescope have detected over 5600 exoplanets suggesting that majority of young rocky exoplanets in the habitable zones around magnetically active cool stars are exposed to extreme stellar coronal X-ray, Extreme UV (EUV) and particle fluxes. They have also revealed frequent (super) flares on young solar-like planet hosting stars, providing a mechanism by which host stars may have profound effects on the physical and chemical evolution of exoplanetary atmospheres. Recent data including our observational campaigns of EK Dra suggest that superflares from young solar analogs are accompanied by fast and energetic coronal mass ejections (CMEs). As CMEs propagate out from the stellar corona into interplanetary space at a few thousand km/s, they drive strong and extended shocks. Shocks are the sites of efficient acceleration of stellar energetic particles (StEPs) to tens of GeVs via diffusive shock acceleration. While CMEs interact with magnetospheres of rocky planets by disturbing them, StEPs can penetrate (exo)planetary atmospheres via open magnetic field and cause significant changes in atmospheric chemistry. Here, I will describe our recent results of observational data-constrained 3D MHD models of initiation and propagation of CMEs in coronae of young solar-like stars and acceleration of shock driven stellar energetic particles (StEP) to 40 GeV. I will then review our recent models of CME interaction with magnetospheres of rocky exoplanets that provide an efficient way for precipitation of StEPs into planetary lower atmospheres. I will also discuss how the flare/StEP modified chemistry may affect climates of rocky exoplanets, the critical factor of habitability. This model was recently validated with our laboratory experiments of proton irradiation of gas mixtures representative of a weakly reducing volcanicaly driven secondary atmospheres of young rocky exoplanets. I will discuss the implications of our recent theoretical simulations and laboratory experiments for the conditions required to find a prebiotic exoplanet around a solar-like stars and its pre-biosignatures.
Vladimir Airapetian (Sun,) studied this question.