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Introduction to the Ulysses encounter with Jupiter
Smith, Edward J.; Wenzel, Klaus-Peter
The Ulysses spacecraft encountered Jupiter in February 1992, passing within 6.31 radii of the planet. For approximately 8 days it was inside the Jovian magnetosphere, and for several days before and after that, Ulysses was in the interaction regions formed by the solar wind (the magnetosheath and boundary layer). The inbound trajectory was at a ~1…
An interpretation of the broadband VLF waves near the Io torus as observed by Ulysses
Kaiser, M. L.; Desch, M. D.; Farrell, W. M. +3 more
The requirements for the Ulysses trajectory to attain high ecliptic latitudes using a Jovian gravitational assist resulted in a fortuitous passage through the Io torus region. Specifically, the spacecraft spend may hours at latitudes just above the torus. During this time the low-frequency cutoff of an ordinary mode (O mode) emission allowed a det…
MHD modeling applied to Giotto encounter with comet P/Grigg-Skjellerup
Neubauer, Fritz M.; Wegmann, R.; Schmidt, H. U.
First from a one-dimensional MHD model we derive estimates for position and shape of the bow shock applicable for arbitrary magnetosonic Mach numbers >1 in the solar wind. This generalization is important in the case of the Giotto encounter with P/Grigg-Skjellerup with the unusual interplanetary magnetic field (IMF) of 18 nT. We compare three-d…
ULF waves in the Io torus: Ulysses observations
Forsyth, R. J.; Rezeau, L.; Lin, Naiguo +7 more
Throughout the Io torus, Ulysses has observed intense ULF wave activity in both electric and magnetic components. Such ULF waves have been previously suggested as the source of ion precipitation leading to Jovian aurorae. The peaks of the wave spectra are closely related to the ion cyclotron frequencies, which is evidence of the waves being ion cy…
Sounder stimulated Dn resonances in Jupiter's Io plasma torus
MacDowall, R. J.; Stone, R. G.; Fainberg, J. +2 more
On February 8, 1992, the Ulysses spacecraft passed through Jupiter's Io plasma torus, where rich spectra of narrow-band resonances were stimulated by the relaxation sounder of the Ulysses unified radio and plasma wave (URAP) instrument. Since the gyrofrequency fg is comparable to the plasma frequency fp in the Io torus, it wa…
Giotto's second encounter: The mission to comet P/Grigg-Skjellerup
Schwehm, G.; Grensemann, M. G.
The second highlight in the life of the Giotto spacecraft, which was originally designed for a short 8-month lifetime, occurred on 10 July 1992. The main mission was to explore and photograph Halley's Comet; however, not only did Giotto survive the harsh environment around the comet Halley but is was also able, after more than 7 years in orbit aro…
Ulysses measurements of energetic H3 molecules in Jupiter's magnetosphere
Lanzerotti, L. J.; Maclennan, C. G.; Feldman, D. M.
The Voyager 2 measurements of energetic (~1 MeV/nucleon) H3 molecules in Jupiter's magnetosphere provided strong evidence that the planet's ionosphere is an important plasma source in the Jovian environment (Hamilton et al., 1980). During the Ulysses spacecraft encounter with Jupiter in February 1992 the Heliosphere Instrument for Spect…
Measurement of direct current electric fields and plasma flow speeds in Jupiter's magnetosphere
Balogh, A.; Goetz, K.; Forsyth, R. J. +3 more
During the encounter of Ulysses with Jupiter, we have measured two components of the dc electric field and deduced from them the flow speed in the Io torus, as well as the presence of a polar cap region and what we interpret as a cleft region. Within the torus the flow speed is approximately equal to the speed of a plasma corotating with Jupiter b…
On the momentum balance along the comet Halley-Sun line during the Giotto flyby
Neubauer, F. M.; Israelevich, P. L.; Ershkovich, A. I.
The plasma velocity along the Sun-comet Halley line is derived by using in situ measurements of the magnetic field along the Giotto trajectory. Including this velocity profile in the momentum balance turns out to be insufficient in order to support the magnetic barrier with conventional parameters of ion-neutral interaction. The observed magnetic …
Upper limits to Jovian hard X radiation from the Ulysses gamma ray burst experiment
Hurley, K.; Sommer, M.; Waite, J. H.
We describe the first in situ search for Jovian X radiation with a dedicated X ray instrument. Upper limits to Jupiter's X ray power in the 27-48 keV range are presented using data taken by the gamma ray burst experiment on the inbound Ulysses trajectory, at distances between 163 and 110 RJ. The data were analyzed using three methods fo…