Stability of Neptune's ring arcs in question

Although all four of the gas-giant planets in the Solar System have ring sy stems, only Neptune exhibits 'ring arcs'-stable dumps of dust that are disc ontinuous from each other(1). Two basic mechanisms for confining the dust t o these arcs have been proposed. The first(2) relies on orbital resonances with two shepherding satellites, while the second(3) invokes a single satel lite (later suggested to be Galatea(4)) to produce the observed ring are st ructures. Here we report observations of the ring arcs and Galatea, which s how that there is a mismatch between the locations of the arcs and the site of Galatea's co-rotation inclined resonance. This result calls into questi on Galatea's sole role in confining the arcs.