Hugh Pickens writes "At the peak of a magnetic storm, the number of highly energetic 'killer electrons' strong enough to damage electronics and human tissue can increase by a factor of more than ten times, posing a danger to spacecraft, satellites, and astronauts. Killer electrons can penetrate satellite shielding, so if electrical discharges take place in vital components, a satellite can be damaged or even rendered inoperable. For many years, the mechanism by which killer electrons are produced has remained poorly understood, in spite of physicists' attempts at solving this puzzle. Now the ESA reports that data shows the increase in the creation of a substantial number of killer electrons is due to a two-step process. First, the initial acceleration is due to the strong shock-related magnetic field compression. Immediately after the impact of the interplanetary shock wave, Earth's magnetic field lines began wobbling at ultra low frequencies. In turn, these ULF waves effectively accelerate the seed electrons (provided by the first step) to become killer electrons. 'These new findings help us to improve the models predicting the radiation environment in which satellites and astronauts operate. With solar activity now ramping up, we expect more of these shocks to impact our magnetosphere over the months and years to come,' says Philippe Escoubet, ESA's Cluster mission manager."