Scientists identify ‘space battery’ powering Earth’s auroras display

Scientists have identified Alfvén waves as the key “space battery” powering Earth’s auroras, solving a longstanding mystery about how charged particles are accelerated to create the spectacular light displays. These plasma waves travel along Earth’s magnetic field lines and continuously recharge the electric fields that drive high-energy particles into the atmosphere, sustaining the aurora rather than allowing it to fade quickly. The discovery was made by an international team led by researchers from The University of Hong Kong and UCLA, who applied insights from the magnetospheres of Jupiter and Saturn to Earth’s auroral processes. The team validated their findings using satellite data from NASA’s Van Allen Probes and the THEMIS mission, which confirmed that Alfvén waves actively replenish energy in the auroral acceleration region. This continuous energy supply prevents the electric fields from collapsing and maintains the aurora’s glow. Beyond explaining Earth’s aurora, the study offers a universal model for auroral phenomena across the solar system and potentially other galaxies, as Alfvén waves