On the morning of August 31, 1859, the sun ejected a giant burst of charged particles. They hit Earth eighteen hours later, creating auroras so bright that at 1:00 A.M. birds sang and people thought morning had dawned. Currents induced in telegraph wires prevented transmission, and sparks from the wires set papers aflame. According to data from ice cores, solar ejections this intense occur about every 500 years.