A critical ingredient for auroras exists much higher in space than previously thought, according to new research in the journal Scientific Reports. The dazzling light displays in the polar night skies require an electric accelerator to propel charged particles down through the atmosphere. Scientists at Nagoya University and colleagues in Japan, Taiwan and the U.S. have found that it exists beyond 30,000 kilometers above the Earth's surface—offering insight not just about Earth, but other planets as well.