Machine-learning-based detection of dust impacts with Juno Waves: Evidence for a new (transient) dusty ring?

Dust dynamics in Jupiter’s inner ring system are effectively shaped by electromagnetic forces arising from the planet’s rapid rotation and intense magnetic field. Previous studies of Jupiter’s rings have relied primarily on optical imaging, which provides initial constraints on the three-dimensional dust distribution and in-situ dynamical processes. The Juno mission offers a unique opportunity to probe the Jovian ring system, as the Waves instrument enables in-situ detection of dust impacts within Jupiter’s innermost magnetosphere.

In this study, we focus on dust impact detections from Juno Waves burst-mode electric field measurements. A convolutional neural network (CNN) is applied to identify dust impact signals and distinguish them from plasma waves and instrumental noise, allowing us to derive dust impact rates and infer dust number densities along the Juno trajectory. These measurements provide new observational constraints on the spatial distribution of dust in Jupiter’s inner ring system.

The inferred dust impact rates and number densities are broadly consistent with previous optical observations of Jupiter’s ring system and with earlier Juno-based dust detections reported by Ye et al. (2020). We find that dust impacts are strongly concentrated near the equatorial plane, with peak impact rates reaching ~8 s⁻¹ and maximum dust number densities of ~3 × 10⁻⁶ m⁻³. These results support the picture of a dense, equatorially confined dust population associated with Jupiter’s inner rings.

In addition to these previously reported features, the Juno observations reveal new characteristics of the dust distribution. In particular, we observe a pronounced north–south asymmetry in the inferred dust number density, as well as a localized density enhancement near ~1.1 R_J along the spacecraft trajectory during a limited number of Juno orbits. Due to the monotonic evolution of the location of the Juno equatorial crossing in the local-time radial distance space, whether this density enhancement represents a transient ring or a spatially confined ring arc remains to be elucidated.