Prospects of X-ray imaging of the outer heliosphere (and other "astrospheres")

Charge-exchange (CX) collisions of the solar wind (SW) high-ionization-state minor ions with LISM neutrals are responsible for much of X-ray production in the outer heliosphere. In this talk, we discuss numerical modeling of the heliospheric CX X-ray production and its contribution to the soft X-ray background. We show that the evolution of the SW ion-composition and the accompanying spectral changes can serve as a useful diagnostic tool for studies of the SW plasma state and evolution. We assess feasibility of CX X-ray detection from the outer heliosphere and astrospheres of nearby stars.