Abstract:
Mass escape rate of mon- and diatomic gases from a planetary atmosphere is studied based on Parkerʼs model for a
broad range of surface conditions. The escape rate is found to follow two asymptotic regimes, namely, high- and
low-density regimes, with a short intermediate regime between them. Equations for the escape rate in every
asymptotic regime are found theoretically. A comparison of the obtained escape rates with results of recent kinetic
simulations shows that Parkerʼs model satisfactorily predicts escape rates only in the high-density regime. Based
on this finding, a criterion of applicability of Parkerʼs model for the calculation of the mass escape rate is
established.
