Atmosphere loss in oblique Super-Earth collisions

ABSTRACT Using smoothed particle hydrodynamics we model giant impacts of Super-Earth mass rocky planets between an atmosphere-less projectile and atmosphere-rich target. In this work, present results from head-on to grazing collisions. The the simulations fall into two broad categories: (1) one main post-collision remnant containing material target projectile; (2) remnants resulting ‘erosive hit-and-run’ All collisions removed at least some atmosphere, in contrast idealized hit-and-run definition which is unchanged. We find that boundary ‘hit-and-run’ result accreting/merging be strongly correlated with mutual escape velocity predicted point closest approach. Our work shows it very unlikely for a single impact remove all atmosphere. For atmosphere removed, require roughly energy catastrophic disruption (i.e. permanent ejection half total system mass) significant erosion mantle. show higher angle collisions, are more common, less efficient removal than Therefore, without substantially disrupting planet not expected during formation.