High above Earth, two giant rings of energetic particles trapped by the planet’s magnetic field create a dynamic and harsh environment that holds many mysteries—and can affect spacecraft traveling around Earth. NASA’s Van Allen Probes act as space detectives, to help study the complex particle interactions that occur in these rings, known as the Van Allen radiation belts. Recently, the spacecraft were in just the right place, at just the right time, to catch an event caused by the fallout of a geomagnetic storm as it happened. They spotted a sudden rise in particles zooming in from the far side of the planet, improving our understanding of how particles travel in near-Earth space.