JUPITERS EXOGENIC DUST RING

Interplanetary and interstellar dust particles stream through the Jovi an magnetosphere where their orbits are perturbed by the Lorentz force . Energy and angular momentum exchange with the magnetosphere can lead to capture of some submicron dust particles into dynamically stable o rbits around Jupiter. The captured grains can be on prograde or retrog rade orbits, and their final orbits are usually in the semimajor axis range of 2 to 20 Jupiter radii, with eccentricities similar to 0.1-0.8 and inclinations less than or similar to 20 degrees. Captured grains have radii between about 0.5 and 1.5 mu m. These captured dust particl es form a diffuse band of material around Jupiter, outside the main Jo vian ring, with a peak normal optical depth of tau less than or simila r to 10(-9) While this is too low for optical detection, the Galileo d ust detector has detected particles on prograde and retrograde orbits around Jupiter whose sizes, orbital properties, and number density are consistent with captured interplanetary and interstellar dust.