This eschaton is a bit different than the previous ones, in that it has more in common with the recent anti-vaccine malarkey than it does with the religious apocalypse scenarios I’ve explored previously.
In the late 1800s, astronomers performing spectral analysis on comet tails revealed that the tail of Haley’s comet contains hydrogen cyanide. Since the Earth periodically passes through the tail of Haley’s comet, and would next do so in 1910, newspapers did the responsible thing and claimed that the world would soon be drenched in deadly cyanide gas. The story soon grew into a full-on end-of-the-world panic, with a run on anti-cyanide pills (often fraudulent) that Carl Sagan famously took on his show “Cosmos.”
Since then, a few things have happened.
First, life on earth failed to end in 1910, despite the Tunguska event in 1908 reminding the world that comets can be extremely dangerous, destructive, and confusing. Course, a lot of people still think the Tunguska event was the result of an exploding alien spacecraft or superweapon rather than the aerial detonation of a comet, so that’s not too surprising.
Second, astronomers have detected various forms of cyanide in the tails of dozens of comets, many of which make close approaches to Earth on regular cycles.
Dutifully ignoring the first of these developments and latching on to every rumor related to the second, a sub-genre of eschatology formed around the idea that cyanide emitted from comets periodically contaminates the atmosphere, leading to mysterious bird deaths and noctilucent clouds. That noctilucent clouds are made primarily of water, like other clouds, apparently escapes these people. So, they attempt to propagate the meme that, any year now, the Earth will collide with or pass through the tail of a particularly deadly comet, and the cyanide rain will kill EVERYTHING.
On the one hand, I have to hand it to these people, since many of them have at least tried to develop a belief based on real things that actually happen, which puts them ahead of a lot of people. Further, the “panic based on limited information” impulse is a hard one to shake. On the other hand, these people are clinging to yet another fanciful version of the “the end is near!” scenario, only they’re all the more certain that people should be worried, because science!
In reality, the density of cyanide in a comet’s tail is several orders of magnitude below the level that most living things are capable of noticing, let alone the level required to kill them. Then, this cyanide is rapidly dispersed to nigh-homeopathic levels as it enters the atmosphere. And even if enough cyanide makes it into the atmosphere to be actually responsible for “mysterious bird deaths,” we’re bigger than most birds and relatively few of us spend most of our time breathing the upper atmosphere. AND, even if enough cyanide shows up to kill most of Earth’s life, numerous highly sheltered biomes will not be affected, and for every situation that will kill most lifeforms, there is a species of bacteria or archaea that will survive it. So, mass poisoning from space just isn’t in the cards.
And then people start likening the possibility of death-by-comet-farts to the line about “casting a mountain into the sea” from the Book of Revelation, or imagining that aliens are in on this process, and I can’t pretend to take this idea seriously anymore.