Solar storm breaches Van Allen radiation belt barrier

A powerful G5 category geomagnetic storm recorded in May 2024 allowed high-energy electrons to penetrate a region of space previously considered a natural protective barrier around Earth. Research led by space physicist Yoshizumi Miyoshi of Nagoya University, published in Geophysical Research Letters, indicates that these ultra-relativistic electrons, sometimes called “killer electrons,” reached energy levels in areas where they were thought unlikely to exist.

Data from the Japanese Arase satellite, which has monitored Earth's radiation belts since 2017, showed that the flux of these particles increased more than 5,000 times during the event. The storm was triggered by solar flares and coronal mass ejections that sent magnetized plasma toward the solar system. Scientists believe the phenomenon reduced cold plasma in the Earth's plasmasphere and favored the emergence of electromagnetic waves, known as chorus waves, which may have accelerated the electrons.

This finding challenges long-held scientific understanding of the Van Allen belts, which are two donut-shaped regions of charged particles trapped by Earth's magnetic field. The breach highlights potential risks to satellites and future space missions during extreme solar activity.