10 years of Juno measurements show linear magnetic holes around Jupiter lasting nearly 40 minutes in some cases. These plasma structures involve a drop in field strength with little change in direction. They appear in both the magnetosphere and the surrounding magnetosheath. The study also finds frequent energetic-electron enhancements, allowing comparison of plasma behavior across planetary environments.
Data collected by the Juno spacecraft around Jupiter show linear magnetic holes lasting nearly 40 minutes in some cases. A magnetic hole is a plasma structure where magnetic-field strength drops relative to its surroundings, rather than an empty cavity in space. Plasma is an environment of charged particles. In the linear examples, field direction changes little. The observed structures can last longer than their near-Earth counterparts.[1]
The researchers examined 10 years of Juno measurements. They found these structures widely across both the magnetosphere, dominated by the planet's magnetic field, and the surrounding magnetosheath. Occurrence rates vary between regions. Drops in magnetic-field strength accompany increases in plasma pressure. The study therefore compares the same kind of structure across different plasma environments around Jupiter rather than examining only one location.[1]
Electron measurements show several distributions of motion directions inside the holes, with isotropic patterns prominent. About 81% of the identified structures contain enhanced energetic-electron fluxes. The authors interpret that association as evidence that magnetic holes affect particle populations around Jupiter. The results contribute to comparisons between structures in this large magnetic environment and examples observed around other planets, including their shared features and differences.[1]
