The vapor fraction of ejecta calculated after decompression is generally lower than at the instantaneous pressure. Pressure vs. entropy phase diagrams for forsterite at five times during a collision with a 1 M_⊕ target, a mass ratio of 0.1 at 5v_esc, and an impact angle of 45^∘ (b = 0.707)—the second collision shown in Figures 1 and A1. Individual SPH particles are plotted as gray dots. The upper row has ejecta particles colored by instantaneous vapor fraction (supercritical fluid is considered as 0% vapor), the lower row has ejecta particles colored by vapor fraction calculated after isentropic decompression to 5.2 Pa. The curve below which particles cannot drop visible in the lower half of the plots for the third column onward is due to the SPH density floor and maximum smoothing length.