Numerically calculated trajectories of dust particles with different impact parameters in the viscous laminar flow around a spherical proto-planetesimal are indicated by solid lines. In this representative example, the proto-planetesimal radius is 10 m, the headwind velocity of the gas is 20 m s^-1, and the particle stopping time is 1 s. The dust particles enter the plot from the right, and the axes have units of meters.