Halleys comet's 1910 pass of Earth was especially close and, thanks to extensive newspaper coverage, eagerly awaited by the general public. In fact, Earth’s orbit carried it through the end of the comet’s 24-million-mile-long tail for six hours on May 19, earning the story the day’s banner headline in The New York Times.
While most reporters turned to astronomers to get the facts straight, the yellow press helped fuel the fears that the end of the world was imminent -that the comet’s tail contained poisonous cyanide gases, and there was danger of a celestial collision with Earth.
In 1910 that spectroscopic studies of comet tails conducted by Sir William Huggins revealed that among the organic molecules found in comets was the gas cyanide. As the Earth was then expected to travel through the tail of Comet Halley, speculation ran riot that people would be asphyxiated by the cyanide molecules.
Gunter Faure and Teresa Mensing note what happened in their textbook Introduction to Planetary Science: The Geological Perspective:
"During the night of May 18/19 of 1910, when the Earth passed through the tail of comet Halley, some people took precautions by sealing the chimneys, windows, and doors of their houses. Others confessed to crimes they had committed because they did not expect to survive the night, and a few panic-stricken people actually committed suicide. Enterprising merchants sold comet pills and oxygen bottles, church services were held for overflow crowds, and people in the countryside took to their storm shelters. A strangely frivolous mood caused thousands of people to gather in restaurants, coffee houses, parks, and on the rooftops of apartment buildings to await their doom in the company of fellow humans."
But the Earth survived unscathed, passing through only a small part of the comet’s tail. A more substantial passage through a comet’s tail had also occurred in 1861 without incidentJason McManus