High-Energy Charged Particles in the Innermost Jovian Magnetosphere

• Published in: Science (American Association for the Advancement of Science) Vol. 272; no. 5263; pp. 856 - 858
• Main Authors: Fischer, H. M., Pehlke, E., Wibberenz, G., Lanzerotti, L. J., Mihalov, J. D.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 10.05.1996; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Astronomical and space-research instrumentation; Astronomy; Atmospheric radiation; Atoms & subatomic particles; Earth, ocean, space; Electrons; Energy; Exact sciences and technology; Fundamental astronomy and astrophysics. Instrumentation, techniques, and astronomical observations; Galileo Probes Jupiter's Atmosphere; Heat shielding; Ionospheres; magnetospheres; Jovian satellites; Jupiter; Jupiter (Planet); Jupiter probes; Lunar, planetary, and deep-space probes; Magnetic fields; Observations; Orbits; Particle energy; Particle telescopes; Planetary, asteroid, and satellite characteristics and properties; Planets; Planets, their satellites and rings. Asteroids; Protons; Radio; Solar system; Space probes; Spacecraft; Telescopes; Protons; Galileo space probes; Energy spectra; Abundance; Angular distribution; Helium ions; Planetary magnetospheres; Jupiter planet; Electrons
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.272.5263.856

The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of lo to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at ∼2.2R$_J$ (where R$_J$ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (∼62 megaelectron volts per nucleon) that peaked at ∼1.5R$_J$ inside the bright dust ring. The abundances of all particle species decreased sharply at ∼1.35R$_J$; this decrease defines the innermost edge of the equatorial jovian radiation.