On the left is an example of simoultaneous mass accretion and erosion. As can be compared in the highlighted frames before and after an impact of a fast dust particle (v = 48.7 m/s) 225 μm in diameter, the small hill on top is lost. At the same time, a new small hill is built up again where the particle impacted the target. On the right is an example for mass accretion. After a multiple impact of dust particles <110 μm in diameter (v = 48.7 m/s), new small hills are built up.