Dust grain orbital behavior around Neptune Original Research Article

The rings of Neptune present an interesting conundrum to current theories of planetary ring stability. It has been assumed in the past that Neptuneʹs rings are composed of clumps of dust, which exhibit quasi-stable orbital parameters due to resonances with Neptuneʹs satellites. The time-scales for the lifetimes of the rings are on the order of millions of years. One question remaining is how the dust acquired their present orbital parameters. Dust, upon escape from one of the Neptunian moons, is affected by a variety of forces including Neptuneʹs gravitational force, the solar radiation pressure force, the solar gravitational force and the gravitational fields produced by Neptuneʹs moons. The dust will also feel the effects of the magnetic field around Neptune after it has acquired a charge. A magnetic field model developed from Voyager spacecraft data is used to determine the magnetic field around Neptune which the dust travels through. The plasma environment around Neptune (which controls charging of the dust) was also examined by the Voyager spacecraft and is used to determine the charge on individual dust particles. This paper investigates the orbital behavior of these dust grains around Neptune after being ejected from one of the inner three moons.