Research Articles

An Explanation for Neptune's Ring Arcs

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Science  30 Aug 1991:
Vol. 253, Issue 5023, pp. 995-1001
DOI: 10.1126/science.253.5023.995


The Voyager mission revealed a complex system of rings and ring arcs around Neptune and uncovered six new satellites, four of which occupy orbits well inside the ring region. Analysis of Voyager data shows that a radial distortion with an amplitude of approximately 30 kilometers is traveling through the ring arcs, a perturbation attributable to the nearby satellite Galatea. Moreover, the arcs appear to be azimuthally confined by a resonant interaction with the same satellite, yielding a maximum spread in ring particle semimajor axes of 0.6 kilometer and a spread in forced eccentricities large enough to explain the arcs' 15-kilometer radial widths. Additional ring arcs discovered in the course of this study give further support to this model.

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