In December 2010, a Russian astronomer named Leonid Elenin had the good fortune to discover a comet. Following the usual practice, it was officially named Comet Elenin, after its discoverer. Once its orbit had been figured out, it caused some excitement amongst the astronomical community because it would pass unusually close to Earth (about 35 million kilometres, or a little less than ten times the distance to the Moon) and therefore had the potential to put on a very good show. Unfortunately, it turned out to be a bit of a dud, never quite getting bright enough to see through binoculars.
Meanwhile, word of this comet had reached a different community, one obsessed with predicting the end of civilisation by means of ancient prophecies and cosmic intervention. As with most other natural events, they figured they could tie it in to the 2012 phenomenon and it didn’t take long for a confused mess of conflicting explanations, conspiracies and prophecies to spread across the internet. Some said that the comet’s gravity was going to whip the Earth out of its orbit, causing changed weather, earthquakes, and general mayhem. Others claimed that the comet was so dim because it was actually a Brown Dwarf, or even the dread planet Nibiru.
Up till now I had ignored these claims as they seemed short-lived. It was a single comet, and the excitement would pass on its own. Weirdly, this hasn’t happened, even though the comet recently began breaking up and will likely not survive its passage around the Sun. But I should have realised this would happen. Prophets of Doom become quite attached to their ideas (perhaps its the fame and attention, or the money to be made from selling scary books) and often find ways to keep a good scam going. Judging from some of the conspiracy theories around this particular comet (Apparently the comet’s name is an acronym for “Extinction Level Event: Nibiru Is Nigh”, which must have come as a surprise to poor Leonid!), I suspect that the photographic proof of the comet’s demise will be ignored or dismissed as part of some great cover-up. Oh well.
But for all my skepticism, there is actually a grain of truth here. Comet scares are not new, as we saw in the great 1911 apparition of Halley’s Comet when Earth passed directly through the great comet’s tail. Thanks to the wonders of spectroscopy, astronomers knew that the comet contained trace amounts of organic compounds including cyanide, and the snake-oil salesmen had a field day selling special comet masks and comet medicine that would save the general population. Needless to say, the billions of people who had no access to these remedies were not harmed, as the amounts were so small as to be undetectable within the Earth’s atmosphere!
And in the interest of staying honest, I must mention that a direct impact – one in which the comet strikes Earth directly, as opposed to passing hundreds of millions of kilometers away, is a very serious event. That would be very noticeable, and comparable to an asteroid impact. If it were to miss the vast majority of Earth’s mostly human-free surface and strike a city, it would have a massive disaster with potentially millions killed. But comets aren’t as stealthy as asteroids – once they pass within the orbit of Jupiter they become easy to spot with small telescopes and binoculars, and there are thousands of amateur astronomers scanning the sky every evening looking for them (Why? The fame and glory of having a heavenly body named after yourself, that’s why!). The race to be a comet’s discoverer means that comets get announced publicly even before their orbits are calculated. A comet on a collision course with a city on Earth would be widely known, and would give us months (at least) to begin emergency evacuations. So… serious, but not the end of the world.
And little comet Elenin? Well, after I started writing this article and before I finished it, Leonid Elenin announced that his comet no longer exists – it flew too close to the Sun, melted and broke apart. That particular apocalypse isn’t going to happen.