Snowballs near Comet Hartley-2

Caption NASA:"This movie shows the motion of some Icy Particles in the Cloud around Comet Hartley 2, as seen by NASA's EPOXI mission Spacecraft. A star moving through the background is marked with red and moves in a particular direction and with a particular speed, while the Icy Particles move in random directions. The Icy Particles are marked in green, blue and light blue.
The images for the movie were obtained by the Medium-Resolution Imager on Nov. 4, 2010, the day the EPOXI mission Spacecraft made its closest approach to the Comet".