Mass loss processes in titan's upper atmosphere

Abstract

Although Titan's atmospheric column density is about ten times that of the Earth's, its measured 15N/14N ratio suggests that considerable escape has occurred or that Titan's original material had a ratio closer to that of cometary materials. A number of active escape processes have been proposed: thermal escape, chemical-induced escape, slow hydrodynamic escape, pick-up ion loss, ionospheric outflow and plasma-ion-induced atmospheric sputtering. These loss processes and relevant simulations are reviewed in light of recent Cassini data. © 2010 Springer Science+Business Media B.V.