Search Publications
Velocity space diffusion and nongyrotropy of pickup water group ions at comet Grigg-Skjellerup
Coates, A. J.; Neubauer, Fritz M.; Wilken, B. +1 more
The diffusion of water group cometary ions in velocity space at comet Grigg-Skjellerup was measured during the Giotto spacecraft encounter. The evolution of the collapsed pitch angle and energy distributions during the inbound and outbound passes shows that the timescale for energy diffusion may be similar to that for pitch angle diffusion. Fully …
Morphology and time variation of the Jovian far UV aurora: Hubble Space Telescope observations
Paresce, Francesco; Prange, Renee; Gerard, Jean-Claude +1 more
High spatial resolution images of the north polar region of Jupiter have been obtained with the Faint Object Camera on board the Hubble Space Telescope. The first set of two images collected 87 min apart in February 1992 shows a bright (≃180 kR) emission superimposed on the background in rotation with the planet. Both Ly α images show common regio…
The dusty ballerina skirt of Jupiter
Horanyi, M.; Gruen, E.; Morfill, G.
We suggest a model to explain the unexpected recurrent dust events that were observed during the Jupiter encounter by the dust detector on board the Ulysses spacecraft. This model is based on dust-magnetosphere interactions. Dust particles inside the Jovian magnetosphere collect electrostatic charges and their interaction with the magnetic and ele…
Bernstein waves in the Io plasma torus: A novel kind of electron temperature sensor
Moncuquet, Michel; Meyer-Vernet, Nicole; Hoang, Sang
During Ulysses passage through the Io plasma torus, along a basically north-to-south trajectory crossing the magnetic equator at R~7.8 RJ from Jupiter, the Unified Radio and Plasma Wave experiment observed weakly banded emissions with well-defined minima at gyroharmonics. These noise bands are interpreted as stable electrostatic fluctua…
Correlated variations of UV and radio emissions during an outstanding Jovian auroral event
Moos, H. W.; Bame, S. J.; Zarka, P. +6 more
An exceptional Jovian aurora was detected in the FUV on December 21, 1990, by means of Vilspa and Goddard Space Flight Center (GFSC) International Ultraviolet Explorer (IUE) observations. This event included intensification by a factor of three between December 20 and 21, leading to the brightest aurora identified in the IUE data analyzed, and, in…
Low-frequency electromagnetic plasma waves at comet P/Grigg-Skjellerup analysis and interpretation
Coates, A. J.; Neubauer, Fritz M.; Glassmeier, Karl-Heinz +1 more
The propagation and polarization characteristics of low-frequency electromagnetic wave fields near comet P/Grigg-Skjellerup (P/GS) are analyzed using magnetic field and plasma observations obtained by the Giotto magnetometer experiment and the Johnstone plasma analyzer during the encounter at the comet on July 10, 1992. The results have been physi…
Source characteristics of Jovian narrow-band kilometric radio emissions
Kaiser, M. L.; Desch, M. D.; Zarka, P. +5 more
New observations of Jovian narrow-bank kilometric (nKOM) radio emissions were made by the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in early February 1992. These observations have demonstrated the unique capability of the URAP instrument for determining both the direction and pol…
Source characteristics of Jovian hectometric radio emissions
Stone, R. G.; Fainberg, J.; Reiner, M. J.
Direct confirmation that low-frequency Jovian hectometric (HOM) radio emissions centered near 0° central meridian longitude consist of distinct, oppositely polarized northern and southern beams has been achieved using data from the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in ear…
Jovian electron propagation in three dimensions of the heliosphere: The Ulysses investigations
Balogh, A.; Smith, D. A.; Simpson, J. A. +1 more
We report investigations of Jovian relativistic electrons in the interplanetary medium that provide new insights into both the physical processes by which the Jovian magnetosphere releases its trapped relativistic electrons into the interplanetary medium, and the modes of their interplanetary propagation. These studies were dependent on the unique…
Time-variable magnetospheric radio emissions from Jupiter
Kaiser, M. L.
Jupiter is the source of a large number of independent nonthermal radio sources, all of which vary with time. The known causes of the variations include planetary rotation modulation, modulation by Io and/or its torus, and influence by the solar wind which can reach surprisingly deep into the Jovian magnetosphere. However, a significant number of …