abstract
| - The Jovian ring system is faint and consists mainly of dust. It is comprised of four main components: a thick inner torus of particles known as the "halo ring"; a relatively bright, exceptionally thin "main ring"; and two wide, thick and faint outer "gossamer rings", named for the moons of whose material they are composed: Amalthea and Thebe. The main and halo rings consist of dust ejected from the moons Metis, Adrastea and other unobserved parent bodies as the result of high-velocity impacts. High-resolution images obtained in February and March 2007 by the New Horizons spacecraft revealed a rich fine structure in the main ring. In visible and near-infrared light, the rings have a reddish color, except the halo ring, which is neutral or blue in color. The size of the dust in the rings varies, but the cross-sectional area is greatest for nonspherical particles of radius about 15 μm in all rings except the halo. The halo ring is probably dominated by submicrometre dust. The total mass of the ring system (including unresolved parent bodies) is poorly known, but is probably in the range of 1011 to 1016 kg. The age of the ring system is not known, but it may have existed since the formation of Jupiter.
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