Eberhard Grün

TL;DR: The data from the onboard program of the Galileo spacecraft during its six-year journey to the planet Jupiter was used to detect 2883 particles with an impact rate of up to 20,000 per day whose impact directions are compatible with a Jovian origin this paper.

TL;DR: The KOSI (Kometensimulation) experiments as discussed by the authors have been used to study processes which could lead to a better understanding of cometary nuclei, such as heat transport into the sample, compositional and structural modifications of the sample and release of dust and gas.

TL;DR: A new instrument to analyze the chemical composition of dust particles in situ in space has been developed, a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential.

TL;DR: The photopolarimetric observations rule out the dominating presence of weakly absorbing silicates such as olivine but are compatible with rough moderately absorbing silicate grains having a density decreasing with radius and with rough graphite grains.

Abstract: Dust measurements have been obtained with the dust detector onboard the Galileo spacecraft inside a distance of about 60RJ from Jupiter (Jupiter radius, RJ = 71,492 km) during two periods of about 8 days around Galileo's closest approaches to Ganymede on 27 June and on 6 Sept 1996. The impact rate of submicrometer-sized particles fluctuated by a factor of several hundred with a period of about 10 hours, implying that their trajectories are strongly affected by the interaction with the Jovian magnetic field. Concentrations of small dust impacts were detected at the times of Ganymede closest approaches that could be secondary ejecta particles generated upon impact of other particles onto Ganymede's surface. Micrometer-sized dust particles, which could be on bound orbits about Jupiter, are concentrated in the inner Jovian system inside about 20RJ from Jupiter.