The Structure of Jupiter's Ring System as Revealed by the Galileo Imaging Experiment

The jovian ring system was observed during four orbits of Galileo's nominal mission, when 25 clear-filter images of the rings were taken at spatial resolutions of 23 to 134 km/pixel; the ring appeared fortuitously in an additional 11 images. The tenuous jovian ring system (normal optical depths<10−5) has three components: the halo, main ring, and gossamer ring. The innermost component, atoroidal halo, extends radially from approximately 92,000 to about 122,500 km (near the 3 : 2 Lorentz resonance) and has a full-width, half-maximum thickness of 12,500 km; its brightness decreases with height off the equatorial plane and decreases as the planet is approached. Themain ringreaches from the halo's outer boundary across 6440 to 128,940 km, just interior to Adrastea's orbit (128,980 km); at its outer edge, the main ring takes nearly 1000 km to develop its full brightness. The ring's brightness noticeably decreases around 127,850 km in the vicinity of Metis' semimajor axis (127,980 km). The precise location and nature of the main ring's outer periphery may shift slightly from image to image; the same is true for the “notch” near Metis. The main ring has a faint, vertically extended component that thickens as the halo region is approached. Brightness variations of ±10% are visible in the central main ring and may be due to vertical corrugations, density clumps, or “spokes” in the ring. Unexplained differences between the near- and far-arm brightnesses are visible. We have discovered that thegossamer ring, lying exterior to the main ring, has two primary components, each of which is fairly uniform: one originates just interior to Amalthea's orbit (181,366 km) while the other is situated radially interior to Thebe's orbit (221,888 km). Very faint material continues past Thebe, blending into the background at 250,000 km. The gossamer rings have thicknesses that are comparable to the maximum elevations of these satellites off Jupiter's equatorial plane; from Galileo's nearly equatorial view, the gossamer rings present rectangular end-profiles with greater intensities along their top and bottom surfaces. The rings seem to be derived from the satellites.

[1]  G. Danielson,et al.  Galileo NIMS Near-Infrared Observations of Jupiter's Ring System , 2000 .

[2]  J. Burns,et al.  The formation of Jupiter's faint rings , 1999, Science.

[3]  Joseph A. Burns,et al.  Keck Infrared Observations of Jupiter's Ring System , 1999 .

[4]  J. Burns,et al.  THE SMALL INNER SATELLITES OF JUPITER , 1998 .

[5]  J. Lissauer,et al.  Resonant Satellite Torques on Low Optical Depth Particulate Disks. I. Analytic Development , 1998 .

[6]  Lisa R. Gaddis,et al.  Inflight performance characteristics, calibration, and utilization of the Galileo solid state imaging camera , 1997 .

[7]  J. Burns,et al.  The Vertical Structure of the Jovian Ring , 1996 .

[8]  M. Horányi,et al.  The structure and dynamics of Jupiter's ring , 1996, Nature.

[9]  R. Canup,et al.  Accretion in the Roche Zone: Coexistence of Rings and Ringmoons , 1995 .

[10]  M. Showalter.  Arcs and Clumps in the Uranian λ Ring , 1995, Science.

[11]  J. Burns,et al.  Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains , 1994 .

[12]  M. Horányi.  New Jovian ring , 1994 .

[13]  D. Hamilton.  A Comparison of Lorentz, Planetary Gravitational, and Satellite Gravitational Resonances , 1994 .

[14]  J. Cuzzi.  Evolution of planetary ringmoon systems , 1994 .

[15]  J. Burns,et al.  Ejection of dust from Jupiter's gossamer ring , 1993, Nature.

[16]  E. Grün,et al.  Mechanism for the acceleration and ejection of dust grains from Jupiter's magnetosphere , 1993, Nature.

[17]  J. B. Dalton,et al.  A photometric study of Saturn's Ring , 1992 .

[18]  E. Grün,et al.  Statistics of Saturn's spokes , 1992 .

[19]  Gerhard Neukum,et al.  The Galileo Solid-State Imaging experiment , 1992 .

[20]  J. Burns,et al.  Lorentz resonances and the vertical structure of dusty rings: Analytical and numerical results , 1992 .

[21]  M. Showalter,et al.  Structure and particle properties of Saturn's E Ring , 1991 .

[22]  C. Porco,et al.  Dynamics and structure of the Uranian rings , 1991 .

[23]  J. Burns,et al.  Periodic features in Saturn's F ring: evidence for nearby moonlets , 1990, Nature.

[24]  J. Graham,et al.  Observations of the Jovian Ring and Small Satellites , 1991 .

[25]  T. Northrop,et al.  Gyrophase drifts and the orbital evolution of dust at Jupiter's gossamer ring , 1989 .

[26]  J. Burns,et al.  Orbital evolution of circumplanetary dust by resonant charge variations , 1988, Nature.

[27]  M. Showalter.  Anticipated Time Variations in (our Understanding Of) Jupiter's Ring System , 1989 .

[28]  C. Porco,et al.  Eccentric features in Saturn's outer C ring , 1987 .

[29]  Joseph A. Burns,et al.  The dynamics of weakly charged dust: Motion through Jupiter's gravitational and magnetic fields , 1987 .

[30]  Joseph A. Burns,et al.  Jupiter's ring system - New results on structure and particle properties , 1987 .

[31]  B. Sicardy,et al.  On the Physics of Resonant Disk-Satellite Interaction , 1987 .

[32]  Joseph A. Burns,et al.  Some background about satellites , 1986 .

[33]  J. Burns,et al.  Discovery of Jupiter's ‘gossamer’ ring , 1985, Nature.

[34]  J. Burns,et al.  Lorentz resonances and the structure of the Jovian ring , 1985, Nature.

[35]  J. Lissauer.  Bending waves and the structure of Saturn's rings , 1985 .

[36]  J. Scargle,et al.  Wavy edges suggest moonlet in Encke's gap , 1985 .

[37]  J. Burns,et al.  An Analysis of IRAS Solar System Dust Bands , 1985 .

[38]  G. Danielson,et al.  Saturn's nonaxisymmetric ring edges at 1.95 R(s) and 2.27 R(s) , 1984 .

[39]  Larry W. Esposito,et al.  Saturn's rings - Properties and processes , 1984 .

[40]  J. Lissauer,et al.  Bending waves in Saturn's rings☆ , 1983 .

[41]  J. Burns,et al.  A numerical study of Saturn's F-ring , 1982 .

[42]  E. Dunham,et al.  Limit on possible narrow rings around Jupiter , 1982 .

[43]  G. E. Wood,et al.  Radio occultation of Jupiter's ring: Bounds on optical depth and particle size and a comparison with infrared and optical results , 1981 .

[44]  G. Danielson,et al.  The Jovian ring , 1981 .

[45]  G. Danielson,et al.  Spectra of the Jovian ring and Amalthea , 1981 .

[46]  E. Grün,et al.  A model of the origin of the Jovian ring , 1980 .

[47]  J. Burns,et al.  Physical processes in Jupiter's ring - Clues to its origin by Jove , 1980 .

[48]  G. Danielson,et al.  Ground-based observations of the Jovian ring and inner satellites☆ , 1980 .

[49]  C. Hansen,et al.  Jupiter's rings , 1979, Nature.

[50]  Bradford A. Smith,et al.  The Jupiter System Through the Eyes of Voyager 1 , 1979, Science.

[51]  E. Becklin,et al.  Detection of Jupiter's ring at 2.2 µm , 1979, Nature.

[52]  S. Tremaine,et al.  Towards a theory for the uranian rings , 1979, Nature.

[53]  J. Burns,et al.  The vertical structure and thickness of Saturn's rings , 1978, Nature.

[54]  M. Acuna,et al.  The main magnetic field of Jupiter , 1976 .