Coherent dust cloud observed by three Cassini instruments

TL;DR

This study reanalyzes Cassini data from 2006, providing evidence for a coherent dust cloud near Saturn's equatorial plane, supporting the magnetic bubble hypothesis with multi-instrument observations and analysis.

Contribution

It offers the first detailed analysis of a dust cloud at Saturn using three instruments, confirming its existence and characteristics, and linking it to magnetic bubble phenomena.

Findings

Detection of a dust cloud approximately 1.36 Saturn radii in size.

Repeated signatures across three spacecraft revolutions.

Supporting evidence for a magnetic bubble near Saturn.

Abstract

We revisit the evidence for a "dust cloud" observed by the Cassini spacecraft at Saturn in 2006. The simultaneous data of 3 instruments are compared to interpret the signatures of a coherent swarm of dust that could have remained floating near the equatorial plane. The conspicuous pattern, as seen in the dust counters of the Cosmic Dust Analyser (CDA) and in the magnetic field (MAG), clearly repeats on three consecutive revolutions of the spacecraft. The data of the Radio Plasma and Wave Science (RPWS) appear less decisive but do back our conclusions. The results support the idea of a "magnetic bubble" as reported from both Voyager flybys in the early 1980ies. That particular cloud, which we firstly discovered in the CDA data, is estimated to about 1.36 Saturnian radii in size, and probably broadening. Both the bulk of dust particles and the peak of the magnetic depression seem to drift apart, but this can also be an effect of hitting the cloud at different parts during the traverse.