In 1910, as Earth passed through the tail of Halley's Comet, people bought "Anti-Comet Pills", special "comet umbrellas", and gas masks, because there was public hysteria that all life on Earth would be destroyed by gas - called cyanogen - that was detected in the tail.
When the World Panicked Over Halley's Comet in 1910
When Halley's Comet made its scheduled flyby in 1910, astronomers made a startling announcement: Earth would pass directly through the comet's tail. Even more alarming? They'd detected cyanogen gas in that tail—the same deadly compound used in chemical weapons.
What happened next was pure chaos.
The Great Comet Panic of 1910
Entrepreneurs seized the moment, flooding the market with dubious "protective" products:
- Anti-Comet Pills (sugar pills marketed as antidotes to poison gas)
- Comet umbrellas (regular umbrellas sold at inflated prices)
- Gas masks and respirators
- "Comet insurance" policies
- Sealed rooms and airtight bunkers
Newspapers ran sensational headlines predicting mass extinction. Street vendors hawked their wares to terrified crowds. Some people threw "end of the world" parties, figuring they might as well go out in style.
Why Scientists Weren't Worried
The astronomers who discovered the cyanogen tried desperately to calm everyone down. Yes, the gas existed in the comet's tail. But they'd done the math.
The comet's tail, while millions of miles long, was so incredibly diffuse that its density was lower than the best laboratory vacuum. When Earth passed through it on May 19, 1910, we'd be exposed to an amount of cyanogen that was essentially zero.
One scientist compared it to dropping a grain of salt into Lake Superior and worrying about the ocean getting too salty.
What Actually Happened
Earth passed through Halley's tail exactly as predicted. People looked up at the sky. Some saw beautiful displays. Others saw... nothing at all.
Not a single person died from comet gas. The anti-comet pills went into desk drawers. The special umbrellas became regular umbrellas again. Life continued exactly as before.
The snake oil salesmen, however, made a killing.
The 1986 Sequel
When Halley's Comet returned in 1986, you'd think we'd learned our lesson. And mostly we had—there were no anti-comet pills this time. But conspiracy theorists still warned about government cover-ups and cosmic dangers. Some things never change.
The real danger in 1910 wasn't the comet. It was fear combined with scientific illiteracy and opportunistic scammers. The same toxic combination that fuels modern pseudoscience and panic.
Next time Halley's visits in 2061, save your money. The comet's tail is still just as harmless, even if it still contains cyanogen. Space is big, comet tails are thin, and you definitely don't need an umbrella.