Characterization of Dust in Saturn's Rings Using Cassini Spacecraft Data

Abstract The dust distribution in Saturn's rings is investigated using dust impacts registered by the Radio and Plasma Wave Science (RPWS) instrument onboard the Cassini spacecraft. Dust impacts, recorded as spiky signals in electric field waveforms, are used to determine profiles of impact rates and amplitudes of spikes during individual equatorial plane crossings. These profiles are compared with the wave power in the 2–12 kHz frequency range, demonstrating that it can serve as a proxy for the dust impact level (impact rates and signal amplitudes) if there are no other sources, such as waves. This approach allows for the evaluation of dust impact levels even during intervals when high‐resolution waveform data is unavailable. We show that the total wave power increases with the relative velocity between the dust and the spacecraft, following a power‐law dependence with an exponent of approximately 8.8 and a velocity threshold of around 6 km/s. The dust impact level in individual crossings roughly follows a Gaussian profile centered on the Saturn equatorial plane. The corresponding Gaussian parameters (dust density peak, full width at half maximum, and displacement from the equatorial plane) are determined for all available crossings. The thickness of the rings increases with the radial distance, from about 1,000 km for the F‐ring up to about 10,000 km for the E‐ring.