On May 18 and 19, 1910, Earth passed through the tail of Halley’s Comet. The world’s greatest scientists assured everyone that no harm would befall the planet. But uncertainty and fear grew as the comet drew ever closer. Newspapers fanned the flames; they ran dozens of stories each day, with headlines shouting: ”Entire World Eagerly Awaits Comet” and “Host of Converts at Revivals, All Afraid of Comet” and “To Escape the Comet, Hire Submarine Boat.”