  Subsonic motion of a large particle moving through the bulk of a dust crystal
formed by negatively charged small particles is investigated using the PK-3
Plus laboratory onboard the International Space Station. Tracing the particle
trajectories show that the large particle moves almost freely through the bulk
of plasma crystal, while dust particles move along characteristic alpha-shaped
pathways near the large particle. In the hydrodynamic approximation, we develop
a theory of nonviscous dust particles motion about a large particle and
calculate particle trajectories. A good agreement with experiment validates our
approach.
