Escape from a 1 M_⊕ and R_⊕ planet located at 0.02 au from its star. Top: mass of H vs. time for different initial mass fractions of hydrogen. Bottom: mass fraction of lost Si(red) and Na(blue) vs. time. The solid line shows these relations for an initial H mass fraction of 10⁻⁶ times the planet mass, and the dashed line is for an initial H mass fraction of 0.1 times the planet mass.