Breach of the Shield: Magnetic links between sun and Earth last hours

Each time the sun hurls a planet-size cloud of charged particles toward Earth, there’s a potential for power outages and satellite damage. But it’s when the magnetic field carried by these billion-ton clouds points opposite to Earth’s magnetic field that geomagnetic storms are most severe. In that configuration, our planet’s field, which usually shields Earth from the sun’s outbursts, connects directly to the field accompanying the cloud.