Krüger, H., E. Grün, D.P. Hamilton, M. Baguhl,
S. Dermott, H. Fechtig, B.A. Gustafson, M.S. Hanner, A. Heck, M.
Horanyi, J. Kissel1, B.A. Lindblad, D. Linkert, G. Linkert, I. Mann,
J.A.M. McDonnell, G.E. Morfill, C. Polanskey, R. Riemann, G. Schwehm,
R. Srama, and H.A. Zook. Three years of Galileo dust data: II. 1993
to 1995. Planet. Space Sci. 47, 85-106.
Between January 1993 and December 1995 the Galileo spacecraft
traversed interplanetary space between Earth and Jupiter and arrived
at Jupiter on 7 December 1995. The dust instrument onboard the
spacecraft was operating during most of the time and data from the
instrument were obtained via memory readouts which occurred at rates
between twice per day and once per week. All events were classified
by an onboard program into 24 categories. Noise events were usually
restricted to the lowest categories (class 0). During Galileo's
passage through Jupiter's radiation belts on 7 December 1995 several
of the higher categories (classes 1 and 2) also show evidence for
contamination by noise. The highest categories (class 3) were
noise-free all the time. A relatively constant impact rate of
interplanetary and interstellar (big) particles of 0.4 impacts per day
was detected over the whole three-year time span. In the outer solar
system (outside about 2.6 AU) they are mostly of interstellar origin,
whereas in the inner solar system they are mostly interplanetary
particles. Within about 1.7 AU from Jupiter intense streams of small
dust particles were detected with impact rates of up to 20,000 per day
whose impact directions are compatible with a Jovian origin. Two
different populations of dust particles were detected in the Jovian
magnetosphere: small stream particles during Galileo's approach to the
planet and big particles concentrated closer to Jupiter between the
Galilean satellites. There is strong evidence that the dust stream
particles are orders of magnitude smaller in mass and faster than the
instrument's calibration, whereas the calibration is valid for the big
particles. Because the data transmission rate was very low, the
complete data set for only a small fraction (2525) of all detected
particles could be transmitted to Earth; the other particles were only
counted. Together with the 358 particles published earlier, a set of
2883 particles detected by the dust instrument during Galileo's six
years' journey to Jupiter is now available.
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