摘要
We analyze the data of the Galileo dust detector system (DDS) with respect to micrometer-sized dust grains in the inner jovian system. The analysis of these data requires an in-depth modeling because an exact determination of the orbits of individual particles directly from the data is not possible. We find that a ring of prograde particles with masses between 10−12 and 10−11 g is compatible with the data. The number density in the region around Europa's orbit is at least 4×10−13 cm−3. The strongest impacts observed, however, are caused by a smaller population of particles in the same mass range but on retrograde orbits. These particles are probably captured interplanetary or interstellar grains (J. E. Colwell et al. 1998, Science280, 88). Possible sources for the prograde dust are the Galilean satellites, especially Europa and Io.