During its Feb. 14, 2011, flyby of comet Tempel 1, an instrument on the protective shield on NASA's Stardust spacecraft was pelted by dust particles and small rocks, as can be heard in this audio track. The instrument, called the Dust Flux Monitor instrument, measures sound waves and electrical pulses from dust impacts. The movie is a visual representation of the sounds.
Scientists think that the observed bursts of particles are from clumps of debris, formed by fragmenting balls of ice and dust. This and other comet studies show that, contrary to previous expectations, icy dust balls that leave a comet continually break up in space.
The movie and audio track represent a fraction of the approximately 5,000 total impacts observed over a period of about 11 minutes.