A tenuous dust ring of Jupiter formed by escaping ejecta from the Galilean satellites

[1] This paper focuses on the dust environment between the orbits of the Galilean moons of Jupiter. Recent discovery of dust clouds around the Galilean satellites formed by impact ejecta from hypervelocity impacts of interplanetary micrometeoroids [Kruger et al., 1999d] suggests that a fraction of the ejected particles may escape from the source satellites into circum-Jovian orbits. We estimate production rates and study dynamical evolution of the escaping ejecta, controlled by gravitational, radiation pressure, and electromagnetic forces, to show that grains larger than several tenths of a micrometer in radius are likely to stay in bound orbits around Jupiter for tens or hundreds of years until they either are lost to collisions with the satellites or Jupiter or are ejected to interplanetary space. It is concluded that these small debris form a broad dust ring with number densities up to ∼103 km−3, extending at least from Europa's orbit outward beyond the orbit of Callisto. Our results are consistent with in situ measurements of the Galileo spacecraft. We analyze impact events recorded by the Galileo dust detector from 1996 through 2001 and find more than 200 events outside the orbit of Europa, compatible with impacts of particles orbiting Jupiter in prograde orbits. An empirical dust number density distribution derived from these data agrees quite well with the theoretical one.

[1]  B. A. Lindblad,et al.  One year of Galileo dust data from the Jovian system: 1996 , 2001 .

[2]  P. Lamy.  Interaction of interplanetary dust grains with the solar radiation field , 1974 .

[3]  A. Heck,et al.  Io as a source of the jovian dust streams , 2000, Nature.

[4]  A. Heck,et al.  Analysis of the sensor characteristics of the Galileo dust detector with collimated Jovian dust stream particles , 1999 .

[5]  D. Hamilton,et al.  Motion of dust in a planetary magnetosphere - Orbit-averaged equations for oblateness, electromagnetic, and radiation forces with application to Saturn's E ring , 1993 .

[6]  A dust cloud of Ganymede maintained by hypervelocity impacts of interplanetary micrometeoroids , 2000, astro-ph/0006209.

[7]  Joseph A. Burns,et al.  The Structure of Jupiter's Ring System as Revealed by the Galileo Imaging Experiment , 1999 .

[8]  A. Showman,et al.  The Galilean satellites. , 1999, Science.

[9]  E. Grün,et al.  Capture of interplanetary and interstellar dust by the jovian magnetosphere. , 1998, Science.

[10]  David P. Hamilton,et al.  Dust Measurements During Galileo's Approach to Jupiter and Io Encounter , 1996, Science.

[11]  J. Burns,et al.  The ethereal rings of Jupiter and Saturn , 1984 .

[12]  Kai-Uwe Thiessenhusen,et al.  Dust Grains around Jupiter—The Observations of the Galileo Dust Detector , 2000 .

[13]  A. Nakamura,et al.  Velocity Measurements of Impact Ejecta from Regolith Targets , 1997 .

[14]  E. Grün,et al.  The dusty ballerina skirt of Jupiter , 1993 .

[15]  E. Grün,et al.  Observations of Electromagnetically Coupled Dust in the Jovian Magnetosphere , 1998 .

[16]  Gregor E. Morfill,et al.  Three years of Galileo dust data , 1995 .

[17]  S. Su,et al.  On Dust Particles in the Jovian System , 1982 .

[18]  J. Burns,et al.  The Dynamics of Saturn's E Ring Particles , 1992 .

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

[20]  Theory of Motion of Jupiter’s Galilean Satellites , 1977 .

[21]  W. Frisch.  Hypervelocity impact experiments with water ice targets , 1991 .

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

[23]  Manabu Kato,et al.  Ice-on-Ice Impact Experiments , 1995 .

[24]  David P. Hamilton,et al.  Origin of Saturn's E Ring: Self-Sustained, Naturally , 1994, Science.

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

[26]  A. Heck,et al.  Galileo observes electromagnetically coupled dust in the Jovian magnetosphere , 1998 .

[27]  D. Humes.  The Jovian meteoroid environment , 1976 .

[28]  E. Sieveka,et al.  Plasma ion-induced molecular ejection on the Galilean satellites - Energies of ejected molecules , 1983 .

[29]  E. Grün,et al.  Reduction of Galileo and Ulysses dust data , 1995 .

[30]  E. Grün,et al.  Detection of an impact-generated dust cloud around Ganymede , 1999, Nature.

[31]  J. Burns,et al.  Radiation forces on small particles in the solar system , 1979 .

[32]  Douglas P. Hamilton,et al.  Circumplanetary Dust Dynamics: Effects of Solar Gravity, Radiation Pressure, Planetary Oblateness, and Electromagnetism , 1996 .

[33]  Mihaly Horanyi,et al.  CHARGED DUST DYNAMICS IN THE SOLAR SYSTEM , 1996 .

[34]  E. Everhart.  An efficient integrator that uses Gauss-Radau spacings , 1985 .

[35]  Douglas P. Hamilton,et al.  Martian Dust Belts: Waiting for Discovery , 1997 .

[36]  E. Grün,et al.  The Galileo Dust Detector , 1992 .

[37]  R. Srama,et al.  Three years of Galileo dust data: II. 1993-1995 , 1998, astro-ph/9809318.