Halley’s 1910 Tail Panic: Spectroscopy, Sensationalism and a Poison That Wasn’t

Earth crossed Halley’s 1910 tail after cyanogen was spectroscopically detected, but the tail was so diffuse that no harmful effect occurred. Sensational reporting turned the finding into a poison scare, fueling sales of comet pills, leather inhalers, gas masks and even ‘comet insurance,’ despite the science distinguishing detection from a dangerous dose. Later analyses and missions clarified the physics of an extremely thin tail, underscoring how media framing can mislead when scale and exposure aren’t understood.