Saturn's magnetosphere: An example of dynamic planetary systems

Journal Article · Tue Jan 04 04:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3544327· OSTI ID:21510084

Krimigis, Stamatios M ^[1]

---

1. Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, 20723 (United States)

Planetary magnetospheres are prime examples of interacting plasma regimes at different scales. There is the principal interaction with the solar wind that seems to be the main driver of the dynamics at Mercury and Earth. But these inner planet magnetospheres are relatively simple when compared to those of the outer planets which are primarily driven by planetary rotation and include internal plasma sources from various moons and rings, in addition to those from the planetary ionospheres and the solar wind. Io's volcanic source at Jupiter is a prime example, but now Enceladus at Saturn has joined the fray, while Titan is a surprisingly minor player despite its thick nitrogen atmosphere and its continued bombardment by energetic particles. Mass loading of plasma leads to interchange instability in the inner magnetospheres at both Jupiter and Saturn, while ionospheric slippage, among other processes, seems to contribute to a variable rotation period in the spin-aligned dipole field of Saturn, manifested in auroral kilometric radiation (SKR), components of the magnetic field itself, and the plasma periodicities measured at several energies. Through use of the ENA (energetic neutral atom) technique, it is now possible to observe bulk motions of the plasma and their connection to planetary auroral processes. Such imaging at Saturn by Cassini has revealed the location of a region of post-midnight acceleration events that seem to corotate with the planet and coincide with auroral brightening and SKR. Periodic injections of plasma have been identified and repeat at the Kronian rotation period of 10.8 hours. A semi-permanent but asymmetric ring current has also been imaged, located between the orbits of the satellites Rhea ({approx}9 RS) and Titan ({approx}20 R{sub S}), with a maximum at {approx}10{+-} 1R{sub S} and dominated by the hot (>3 keV) plasma component.

• OSTI ID: 21510084
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1320; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ANGULAR MOMENTUM
ASYMMETRY
ATMOSPHERES
CURRENTS
DIPOLES
ELECTRIC CURRENTS
ELEMENTS
ENERGY RANGE
FLUTE INSTABILITY
INSTABILITY
INTERACTIONS
JUPITER PLANET
KEV RANGE
MAGNETIC FIELDS
MASS
MERCURY
METALS
MULTIPOLES
ORBITS
PARTICLE PROPERTIES
PARTICLES
PERIODICITY
PLANETARY ATMOSPHERES
PLANETARY IONOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RING CURRENTS
SATURN PLANET
SOLAR ACTIVITY
SOLAR WIND
SPIN
STELLAR ACTIVITY
STELLAR WINDS
VARIATIONS