Dust measurements in the coma of comet 81P/Wild 2 by the Dust Flux Monitor Instrument

摘要

We present measurements of the dust particle flux and mass distribution from the Stardust Dust Flux Monitor Instrument (DFMI) throughout the flyby of comet 81P/Wild 2. In the particle mass regime from 10(-14) to 10(-7) kilograms, the spacecraft encountered regions of intense swarms of particles, together with bursts of activity corresponding to clouds of particles only a few hundred meters across. This fine-scale structure can be explained by particle fragmentation. We estimate that 2800+/-500 particles of diameter 15 micrometers or larger impacted the aerogel collectors, the largest being similar to6x10(-7) kilograms, which dominates the total collected mass.