  Energetic flares and associated coronal mass ejections (CMEs) from young
magnetically active solar-like stars can play a critical role in setting
conditions for atmospheric escape as well aspenetration of accelerated
particles into their atmospheres that promotes formation of biologically
relevant molecules. We have used the observationally reconstructed magnetic
field of the 0.7 Gyr-young Suns twin, k1 Ceti, to study the effects of CME
deflections in the magnetic corona of the young Sun and their effects on the
impact frequency on the early Venus, Earth and Mars. We find that the coronal
magnetic field deflects the CMEs toward the astrospheric current sheet (ACS).
This effect suggests that CMEs tend to propagate within a small cone about the
ecliptic plane increasing the impact frequency of CMEs with planetary
magnetospheres near this plane to ~ 30 percent or by a factor of 6 as compared
to previous estimate by Airapetian et al. 2016. Our model has important
implications for the rise of prebiotic chemistry on early terrestrial planets
as well as terrestrial type exoplanets around young G-K dwarfs.
