Abstract Saturn's magnetosphere is dominated by Enceladus‐sourced neutrals, which spread throughout the system into the magnetosheath. The neutrals can charge exchange with highly charged solar wind ions, causing soft X‐ray emission ( keV) upon de‐excitation of the ion. Imaging these soft X‐rays can reveal the global, dynamic structure of the magnetosheath and cusps of a magnetosphere and give insight into the complex nature of the solar wind interaction with the planet. A model of soft X‐ray emission from Saturn's magnetosheath is presented, considering charge exchange between Enceladus‐sourced neutrals and highly charged oxygen ions ( and ). We estimate emission rates and the flux that would be detected by a SMILE‐like soft X‐ray imager (SXI). Solar wind dynamic pressure is varied to test the effect of solar wind conditions on X‐ray production. Volumetric emission rate is on the order of and photon for slow and fast solar winds, respectively. A compressed magnetosphere has higher neutral density in the magnetosheath leading to more emission. For a SMILE‐like SXI imaging at a distance of 53 , we estimate over a hundred photons can be detected within a quarter of a planetary rotation. A “future” SXI, with double the FOV of SMILE's and 100 effective area, significantly improves integration times, reducing integration time to s when imaging at 25 . Under a point source approximation, the modeled SXIs perform well to large distances, with Earth‐based observations potentially being possible with an XMM‐Newton‐like instrument.
Naylor et al. (Fri,) studied this question.