  An ionization plays a key role in formation of stars, planets and their
atmospheres. Cosmic rays (CR) are the main source of the ionization, therefore
it is important to know and be able to estimate fluxes of galactic and stellar
cosmic rays (GCR and SCR) at different stages of evolution of stars and
planetary systems. Radiation conditions close to exoplanets might be important
for creation and development of life. We present a review of the current state
of the problem of astrospheres and their interactions with GCR and SCR. We pay
special attention to estimates of radiation conditions near exoplanets recently
discovered in a habitable zone of their hosting stars.
