NASA releases a photo of Jupiter’s narrow ring measuring about 1,000 km (600 miles) wide with a fainter sheet of material inside it. A planetary astronomer suggests that the ring’s largest boulders are corralled into a narrow belt by the influence of Jupiter’s two innermost moons. The ring also appears to darken in the middle, a possible hint that a smaller, undiscovered moon is clearing out a gap. The faint glow extending in from the ring, the “halo,” is likely caused by fine dust that diffuses in toward Jupiter.
This is one of the clearest pictures ever taken of Jupiter’s faint ring system. The ring looks different from what we expected it has usually appeared much wider.