More than a year after the sun lashed out at Earth with the most powerful set of storms ever recorded, a fleet of space probes continues to track the reverberations. The data document in frightening detail how the sun’s outbursts buffet Earth and the other planets of the solar system.
The action began around Halloween 2003, when a series of solar flares caused huge eruptions, known as coronal mass ejections, on the surface of the sun. Within minutes after the first flare, Earth was rocked with radiation. A squall of subatomic particles, including electrons and protons, raced out at 5 million miles per hour and slammed into our magnetic field, which deflected most of the blow. Still, airplanes had to be rerouted away from polar flight paths, satellite communications were disrupted, and astronauts in the International Space Station scurried for cover in the heavily shielded Russian-built part of their orbiting ...