Assessing the Lifetime of The Primary Atmospheres of Early Earth and Mars with PLANET ITTR and GITM models

Abstract:

Primary Hydrogen-rich and Magma Ocean (MO) outgassed atmospheres of Earth and Mars in the first 100 Myr were exposed by high fluxes of X-ray and Extreme UV (XUV) radiation from the quiescent corona and frequent flare events from the young Sun. We reconstruct the XUV fluxes from the young Sun and use them as input for our sophisticated one-dimensional Planet Ionosphere Thermosphere Tool for Research (ITTR) to calculate the rate of atmospheric escape of hydrogen-rich and magma ocean outgassed (CO2-H2O) atmospheres of early Earth and Mars. We used Global Ionosphere Thermosphere (GITM) model as a benchmark for these calculations. We derive the epochs in the history of Earth and Mars when the atmospheric erosion was driven by hydrodynamic escape and ion escape processes. This provides the lifetime of the primary atmospheres that sets the epoch for initiation of the secondary atmospheres from these planets.