Jupiter’s magnetosphere is the largest and most powerful in the solar system, stretching up to 7 million kilometers toward the Sun and extending beyond Saturn’s orbit on the opposite side. This immense magnetic field, approximately 20 times stronger than Earth’s, is generated by electrical currents in Jupiter’s outer core, composed of liquid metallic hydrogen. The magnetosphere acts as a vast shield, deflecting solar wind and creating a cavity that dwarfs all other planetary magnetic fields.
A significant contributor to Jupiter’s magnetospheric dynamics is its moon Io, the most volcanically active body in the solar system. Io ejects about one ton of material per second into space, forming a torus of plasma that feeds into Jupiter’s magnetosphere. This interaction not only enhances the magnetosphere’s strength but also leads to the formation of intense radiation belts and auroras. These auroras, observed in ultraviolet and X-ray wavelengths, are among the most energetic in the solar system.
NASA’s Juno mission has provided unprecedented insights into Jupiter’s magnetosphere. Notably, it detected Kelvin-Helmholtz instabilities—giant swirling waves at the boundary between Jupiter’s magnetosphere and the solar wind. These waves facilitate the transfer of energy and plasma into the magnetosphere, influencing its structure and dynamics. Additionally, Juno observed changes in Jupiter’s magnetic field over time, a phenomenon known as secular variation, suggesting complex internal processes.
