Radio and Plasma Wave Observations at Saturn from Cassini's Approach and First Orbit

TLDR

The study reports data from Cassini’s radio and plasma wave instrument during the spacecraft’s approach and first orbit around Saturn. Data were collected by the instrument during the approach and initial orbit, providing measurements of Saturn’s radio emissions and plasma environment. The approach revealed a 10 h 45 m 45 s radio rotation period, roughly six minutes longer than Voyager’s 1980–81 measurement, detected intense impulsive radio signals from Saturn lightning linked to storm systems, and observed whistler‑mode auroral hiss near the rings, indicating strong electrodynamic interactions in or near the rings.

Abstract

We report data from the Cassini radio and plasma wave instrument during the approach and first orbit at Saturn. During the approach, radio emissions from Saturn showed that the radio rotation period is now 10 hours 45 minutes 45 +/- 36 seconds, about 6 minutes longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive radio signals were detected from Saturn lightning during the approach and first orbit. Some of these have been linked to storm systems observed by the Cassini imaging instrument. Within the magnetosphere, whistler-mode auroral hiss emissions were observed near the rings, suggesting that a strong electrodynamic interaction is occurring in or near the rings.