The unresolved mystery of dust particle swarms within the magnetosphere

TL;DR

This paper reviews the detection of dust particle swarms in Earth's magnetosphere, proposing electrostatic meteoroid disruption as a natural creation mechanism and highlighting their correlation with geomagnetic activity.

Contribution

It introduces the electrostatic disruption hypothesis for dust swarms and correlates observations from HEOS-2 and GORID with geomagnetic activity, offering a new perspective on natural dust phenomena.

Findings

Dust clusters occur throughout Earth's magnetosphere up to 60,000 km altitude.

A correlation exists between dust clusters and increased geomagnetic activity.

Electrostatic meteoroid disruption is a plausible natural mechanism for swarm formation.

Abstract

Early-generation in-situ dust detectors in near-Earth space have reported the occurrence of clusters of sub-micron dust particles that seemed unrelated to human spaceflight activities. In particular, data from the impact ionization detector onboard the HEOS-2 satellite indicate that such swarms of particles occur throughout the Earth's magnetosphere up to altitudes of 60,000 km -- far beyond regions typically used by spacecraft. Further account of high-altitude clusters has since been given by the GEO-deployed GORID detector, however, explanations for the latter have so far only been sought in GEO spaceflight activity. This perspective piece reviews dust cluster detections in near-Earth space, emphasizing the natural swarm creation mechanism conjectured to explain the HEOS-2 data -- that is, the electrostatic disruption of meteoroids. Highlighting this mechanism offers a novel viewpoint on more recent near-Earth dust measurements. We further show that the impact clusters observed by both HEOS-2 and GORID are correlated with increased geomagnetic activity. This consistent correlation supports the notion that both sets of observations stem from the same underlying phenomenon and aligns with the hypothesis of the electrostatic breakup origin. We conclude that the nature of these peculiar swarms remains highly uncertain, advocating for their concerted investigation by forthcoming dust science endeavours, such as the JAXA/DLR DESTINY+ mission.