Comparison between the new collision model (top) and the model of Güttler et al. (2010) (bottom). The left and right panels show the outcome for equal- and differently sized collisions, respectively. Green regions mark collisions that are growth-positive for the target, yellow marks growth-neutral, and red marks growth-negative. “S” marks sticking, “SB” the sticking to bouncing transition, “B” bouncing, “MT” net mass transfer, “E” net erosion, and “F”, fragmentation. In the transition region, the green parallel lines each mark a decrease in sticking probability by 20%.