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Discovery of Jovian dust streams and interstellar grains by the Ulysses spacecraft
Forsyth, R.; Balogh, A.; Bame, S. J. +20 more
ON 8 February 1992, the Ulysses spacecraft flew by Jupiter at a distance of 5.4 AU from the Sun. During the encounter, the spacecraft was deflected into a new orbit, inclined at about 80° to the ecliptic plane, which will ultimately lead Ulysses over the polar regions of the Sun1. Within 1 AU from Jupiter, the onboard dust de…
Detection of Interstellar Pick-Up Hydrogen in the Solar System
Balsiger, H.; Geiss, J.; Galvin, A. B. +6 more
Interstellar hydrogen ionized primarily by the solar wind has been detected by the SWICS instrument on the Ulysses spacecraft at a distance of 4.8 astronomical units from the sun. This "pick-up" hydrogen is identified by its distinct velocity distribution function, which drops abruptly at twice the local solar wind speed. From the measured fluxes …
Mechanism for the acceleration and ejection of dust grains from Jupiter's magnetosphere
Horanyi, M.; Grun, E.; Morfill, G.
PERHAPS the most unexpected finding of the Ulysses mission so far has been the detection of quasi-periodic streams of high-velocity, submicrometre-sized dust particles during the spacecraft's encounter with Jupiter1. The impact geometry clearly shows that these small grains originate in the jovian system, but it is surprising that any d…
The Ulysses neutral gas experiment: Determination of the velocity and temperature of the interstellar neutral helium
Rosenbauer, H.; Witte, M.; Banaszkiewicz, M. +1 more
A new technique to directly detect low energy neutral helium has been developed and successfully used in space for the first time. It makes possible the in-situ measurement of the local angular distribution of the flow of interstellar neutral helium in the inner heliosphere. Based on the transformation of a velocity distribution, using Liouville's…
Five populations of interplanetary meteoroids
Divine, Neil
A description of the interplanetary meteoroid environment is proposed in terms of distinct populations, each of which has separable distributions in particle mass and in orbital inclination, eccentricity, and perihelion distance. This treatment leads to expressions for particle concentration and flux which explicitly incorporate both Keplerian dyn…
Ulysses observations of a recurrent high speed solar wind stream and the heliomagnetic streamer belt
McComas, D. J.; Goldstein, B. E.; Bame, S. J. +4 more
Near-ecliptic solar wind observations by Ulysses on its way to the polar regions of the Sun, compared with those from IMP 8 at 1 AU, showed that high-speed streams decay and broaden with heliocentric distance from IMP 8 to Ulysses, as expected. In July 1992 while travelling south at ∼13°S and 5.3 AU, Ulysses encountered a recurrent high-speed stre…
Perpendicular transport in 1- and 2-dimensional shock simulations
Giacalone, J.; Jokipii, J. R.; Kota, J.
We consider the foundations of 1- and 2-dimensional shock simulations in which the physical quantities are independent of a coordinate which is not parallel to the magnetic field. We show analytically that in such simulations the ions are effectively tied to the convected magnetic lines of force because of the presence of an ignorable spatial coor…
Latitudinal variation of solar wind corotating stream interaction regions: Ulysses
McComas, D. J.; Goldstein, B. E.; Bame, S. J. +4 more
Ulysses’ initial transit to high heliographic latitudes at a heliocentric distance of ∼5 AU has revealed systematic effects in the latitudinal evolution of corotating interaction regions (CIRs). At a latitude corresponding roughly to, but slightly less than, the inferred tilt of the coronal streamer belt and embedded heliospheric current sheet, th…
Disappearance of the heliospheric sector structure at Ulysses
Balogh, A.; Tsurutani, B. T.; Forsyth, R. J. +6 more
In May, 1993, the heliospheric current sheet (HCS) ceased to be seen by the Ulysses spacecraft at a heliocentric latitude of ∼30° S and distance of 4.7 AU. The disappearance of the HCS coincided with the solar wind speed remaining >560 km/s and with the disappearance of one of four interaction regions previously seen on each solar rotation. The…
Quasiperiodic Jovian Radio bursts: observations from the Ulysses Radio and Plasma Wave Experiment
MacDowall, R. J.; Kaiser, M. L.; Desch, M. D. +3 more
The Ulysses flyby of Jupiter has permitted the detection of a variety of quasiperiodic magnetospheric phenomena. In this paper, Unified Radio and Plasma Wave Experiment (URAP) observations of quasiperiodic radio bursts are presented. There appear to be two preferred periods of short-term variability in the Jovian magnetosphere, as indicated by two…