As night was falling across the Americas on Sunday, August 28, 1859, the phantom shapes of the auroras could already be seen overhead. From Maine to the tip of Florida, vivid curtains of light took the skies. Startled Cubans saw the auroras directly overhead; ships’ logs near the equator described crimson lights reaching halfway to the zenith. Many people thought their cities had caught fire. Scientific instruments around the world, patiently recording minute changes in Earth’s magnetism, suddenly shot off scale, and spurious electric currents surged into the world’s telegraph systems. In Baltimore telegraph operators labored from 8 p.m. until 10 a.m. the next day to transmit a mere 400-word press report.