Researchers analyzing data from NASA's Juno spacecraft confirmed the existence of plasma waves at Jupiter's bow shock, according to a study published in Nature Communications. The findings, published on July 31, 2026, rely on two case studies to demonstrate that plasma wave structures operate in the outer planet's high-energy environment.
Solar wind becomes increasingly super-Alfvénic at greater distances from the Sun, producing higher-energy bow shocks that require enhanced energy dissipation. At Earth's bow shock, plasma waves convert kinetic energy from solar wind into thermal energy. These include ion-acoustic waves, electrostatic solitary waves, whistler mode waves, and waves driven by electron cyclotron drift instability. A lack of high-resolution plasma wave data previously hindered identification of these phenomena at outer planets.
Ion-acoustic waves at Jupiter differ from those observed near Earth by displaying harmonic structures, which suggest possible particle trapping. Intense electron cyclotron drift instability also occurs to accommodate the increased shock intensity at Jupiter. Furthermore, magnetic field measurements indicate possible shock reformation.
Lead author J. Joseph conducted the study alongside University of Iowa researchers W. S. Kurth, J. B. Faden, C. W. Piker, and A. N. Jaynes. The team also included L. B. Wilson III and J. E. P. Connerney from NASA Goddard Space Flight Center, F. Allegrini, R. W. Ebert, and S. J. Bolton from the Southwest Research Institute, R. J. Wilson from the University of Colorado Boulder, A. H. Sulaiman from the University of Minnesota, and B. H. Mauk from the JHU/Applied Physics Laboratory.
The paper was received on August 14, 2025, and accepted on July 23, 2026. NASA funded the University of Iowa research under Contract 699041X with the Southwest Research Institute. Data analysis relied on the Space Physics Data Repository at the University of Iowa, funded by the Roy J. Carver Charitable Trust. Darrelle Wilkinson of the University of Iowa assisted the researchers by differentiating electrostatic solitary wave electric field waveforms from waveforms caused by dust impacts.
