William Huggins was a pioneer in the field of spectroscopy. In 1881, he captured the first photographic spectrum of a comet. Credit: Courtesy of Linda Hall Library of Science, Engineering & Technology
On the evening of June 24, 1881, Sir William Huggins directed his reflector, equipped with spectroscopic and photographic tools and located in his private observatory in London, to the head of Comet 1881 III. He captured the first photographic spectrum of a comet, and later analysis of the imagery revealed cyanogen emissions at certain wavelengths. This evidence showed that comets emit their own light, rather than solely reflecting sunlight. It also helped fuel panic 30 years later: When Earth passed through Comet Halley’s tail in May 1910, public fear mounted over predictions that its cyanogen gas could “snuff out all life,” leading to bizarre precautions like gas masks, comet-protection umbrellas, and comet pills.
