Implications of Meteoroid-Ring Interactions for Observations of the 1995 Saturn Ring Plane Crossing

Abstract

Because of its large cross section, Saturn's rings have very strong collisional interaction with the interplanetary meteoroids. The continuous process of impact fragmentation and erosion is a major mechanism driving the mass and angular momentum transport of the ring system with a dynamical time scale estimated to be as short as 10-100 million years. An assessment of the impact ejecta production rate based on results from new laboratory experiments of hypervelocity impacts on ice-silicate mixtures shows that a tenuous dust halo with a half thickness of about 1500 km should form above and below the ring plane. The detection of this ejecta cloud created from interplanetary collisions is most favorable at the unique edge-on viewing condition in 1995 and 1996. The optical depth (τ) of icy grains of sizes of about 10 μm integrated along the light-of-sight can be estimated to be on the order of 2 × 10 -3 which may be within the detection limits of the Hubble Space Telescope and several wound-based facilities.