Lifetime (in Myr) of the MO-outgassed atmosphere as a function of planetary mass (x-axis), and incoming XUV flux (L_XUV, y-axis), normalized by the solar XUV flux received by the Earth 4.5 Ga ($L_{\mathrm{X}\mathrm{U}\mathrm{V}}^{\mathrm{s}\mathrm{u}\mathrm{n}}$(t = 4.5 Ga)) from Ribas et al. (2005), for the cases most prone to hydrodynamic escape (ΔIW = −5 and Φ = 0.1). The loci in which the crossover mass matches the molecular mass of H₂O (black), CO or N₂ (purple), and CO₂ (white) are also represented.