On Mars' Atmospheric Sputtering after Maven First two Years

Mars likely lost a significant part of its atmosphere to space during its history. The sputtering of the atmosphere by precipitating planetary picked up ions accelerated by the solar wind is one of the processes that could have significantly contributed to this atmospheric escape, in particular since the cessation of its global magnetic field, 4.0-4.1 Gyr ago. We here present a two year baseline analysis of MAVEN observations of the precipitating flux, in particular the dependence of the precipitating flux on solar zenith angle. We use this measurement to model the expected escape rate and exospheric structure induced by this precipitation.