X-ray imaging of the solar wind - Mars interaction

Wherever the solar wind meets a neutral atmosphere, X-rays are emitted by c harge-exchange processes between heavy solar wind ions and the neutrals. Us ing an empirical model of the proton flow near Mars we present computer sim ulations of X-ray emissions from this charge-exchange process in Mars' exos phere. We also discuss implications for remote sensing. Here we show that t he total X-ray luminosity near Mars from charge-exchange is greater than 10 (25) eV/s for typical solar wind conditions. This flux is large enough to b e detected by an X-ray satellite in Earth orbit. Thus, Mars belongs to a ne w class of X-ray objects in the sky, together with other non-magnetized pla nets, such as Venus.