We discuss the nature of possible changes in the environment of the solar system considering the presently known information on the physical state of the interstellar matter (ISM) in the vicinity of the sun. We trace the solar motion through the ISM, with particular reference to the consequences of this motion on the composition, flux and energy spectrum of corpuscular radiation in the solar system. We review our present state of knowledge of the ISM, and on the nature of temporal changes in the compositions and fluxes of galactic and anomalous cosmic radiation, due to changes in the solar activity, and the ISM. The plausible changes in the corpuscular radiation fluxes are then estimated, considering the physical state of the ISM at the heliopause-ISM boundary during sun’s journey in the past tens of millions of years.