Researchers find Jupiter’s magnetodisk is a rippling, wavy structure

In October 2026, researchers led by Shandong University found that Jupiter’s magnetodisk forms a rippling, wavy structure that rotates with the planet, contrary to earlier models of a static disk.

Using data from several Juno flybys, researchers examined Jupiter’s magnetic field and energetic particle measurements within the magnetodisk and later published their findings in Science China Earth Sciences. During typical orbits Juno passes through the magnetodisk current sheet twice each Jupiter rotation, roughly every 9.9 hours, yet during reconnection episodes it traversed the sheet many times, detecting identical magnetic signatures accompanied by bursts of energized electrons and ions on nearly every crossing. Study of the current sheet’s orientation revealed a wave‑like motion with ripples persisting from a few minutes up to more than an hour, instead of a simple up‑and‑down movement. Across roughly 100 degrees of longitude, the magnetodisk hosts many small‑scale magnetic reconnection sites that constantly break field lines and displace the sheet from equilibrium.

Since Jupiter’s magnetodisk spins quickly, the whole wavy structure rotates with the planet, whereas in Earth’s magnetotail a kink wave propagates away from the reconnection point. The researchers noted that the wavy sheet might influence how Jupiter’s magnetodisk accelerates and transports Io’s volcanic particles, and could make the connection between Jupiter’s ionosphere and the magnetodisk more complex. They concluded the Jovian magnetodisk is a highly structured, dynamic environment, not a simple rotating sheet. Juno is operating on an extended mission scheduled to continue until September 2028, building on the science of NASA’s Galileo probe.