Examples of the evolution model of the ejecta curtain produced by the impact of SCI projectile. Shown is the half cross-sectional view of the ejecta curtain at each time t = 0.01T, 0.1T, 0.5T, 1T, 2T, 3T, where T is the crater formation time. The thick red lines and green dotted lines indicate the front line (area) of the curtain at each time with τ > 1 and τ < 1, respectively.The thin lines indicate the back lines (area) of the curtain. The blue dotted line indicates the trace of the border of τ = 1. The constituent ejecta particles are assumed to have an equal radius a_m; a_m = 1 mm (left) and 1 cm (right), respectively. The ejection angle is assumed to be 45 deg.