Meng-Tse YANG (National Central University); Wing-Huen IP (National Central University)
The unique ice giant planetary features of Uranus and Neptune are peculiar landscapes in the solar system. The two planets are surrounded by their own ring systems, and both ring systems are narrow and dark. We still have many curious parts about the ring systems of these two ice giant planets (such as the lack of micron dust in the rings of Uranus). That the Uranian rings are relatively free of dust has been explained in terms of the aerodynamic drag effect from collisional interaction with Uranus' exosphere. In this work, we explore the orbital motion of small charged dust particles and show that because of the highly offset and inclined dipole field of the planet, the trajectories could be very chaotic. As a consequence, the charged small dust particles would either hit the upper atmosphere of planets or escape to large distance (this fall pattern can span from the equatorial region to mid-high latitudes). Besides depleting the dust content of the ring system, such a strong gravito-electrodynamical effect would also lead to the injection of CHON material into planet's atmosphere.