Halley's comet, impending doom and communicating science
On May 18, 1910, Halley's comet made its closest recorded contact (0.15 astronomical units,* or approximately 23 million kilometres) with our planet, and the Earth passed through its tail. The event was full of scientific excitement and wonder, since photographic plates and spectroscopy were newly available to researchers. With these new tools, astronomers and the public got a better view of the comet itself and also a first inkling of what it contained.
Exciting times for science!
However, as the comet approached, the spectroscopy results revealed that among other gases, the comet's tail showed strong band signatures for the toxic gas cyanogen. First synthesized in 1815, cyanogen is toxic, since it reduces rapidly to form cyanide and thus poisons the essential cytochrome c oxidase system to mess with mitochondrial function (not good).
Although many chose to report the existence of the gas in the comet tail scientifically and without alarm (because there was no reason for alarm), some did not let science get in the way of a good story and launched into the general doom-mongering that often accompanies the appearance of celestial bodies.
According to astronomer Camille Flammarion, cyanogen gas would extinguish life on Earth as the planet passed through the comet's tail. Despite reassurances from more responsible experts who no doubt pointed out the space/vacuum/distance/protective effect of atmospheric abundancy factors, some news outlets, including the New York Times, chose to report this alarming speculation.
Stardust was okay, but the public was not happy with the thought of being bathed in cyanogen; in the panic, sales of gas masks and comet pills increased.
May 19 dawned; Earth passed safely through the comet tail. Mark Twain, the only "casualty," had died a month earlier (just sayin').
- Clickbait and misreporting science are not new phenomena.
- Communicating science should be done accurately and responsibly to avoid unnecessary panic or profiteering.
- Caveat lector!
For more information on spotting clickbait, check out How do I know it's okay? Swimming through the science communications minefield
* One astronomical unit (AU) is equivalent to the mean distance between the Sun and the Earth, according to this blog post from the Jet Propulsion Laboratory at the California Institute of Technology.