And so the end of the world is nigh. Again. Prophets of doom plan a year-long party because come next December, life as we know it will cease to exist.
But it won't be climate change, or nuclear apocalypse, or the outbreak of an unknown virus that will kill us all.
Instead a rogue planet -- known to the authorities but which is being kept secret from us all -- will crash into Earth, ending humanity's brief time here.
How we all die is beautiful in its simplicity, and based on ancient knowledge and discovery.
The ancient Sumerians, who lived in southern Iraq, discovered a planet called Nibiru, which is hurtling towards Earth and is due to hit next December.
In perfect symmetry, the Mayans -- who came from Central America -- predicted the end of the world on December 21 when its so-called 'Long Count' calendar comes to an end, hailing the 'end of days'.
They didn't actually mention the planet Nibiru -- but that hasn't stopped worldwide apocalyptic alarm.
And luckily for the doomsayers there are even two fragments of writing found in Mexican ruins which refer to Bolon Yokte, a Mayan god associated with war and creation, which probably say (the fragments are broken so are difficult to read): "He will descend from the sky."
So that's that then. That was our last Christmas.
It's been a while since such a doomsday scenario has captured the popular imagination, with bookseller Amazon currently offering more than 170 titles dealing with the Mayan Long Count.
Such was the excitement that NASA was forced to step in last month to counteract the claims, saying if Niburi existed it would now be visible with the naked eye and everyone would know of their impending doom.
"Nothing bad will happen to the Earth in 2012", the space agency said. "Our planet has been getting along just fine for more than four billion years and scientists worldwide know of no threat associated with 2012."
But conspiracy theorists, doomsayers and other believers have no need for scientific evidence. The end is nigh and that's enough. And their predictions aren't a new phenomenon.
Some 20,000 people fled London in January 1524 after astrologers predicted a great flood, while Halley's Comet's arrival in 1910 caused widespread panic that humanity would be wiped out by noxious gases in its tail. In 1919, meteorologist Albert Porta said a rare conjunction of planets would cause magnetic currents "that would pierce the sun, cause great explosions of flaming gas and eventually engulf the Earth".
A rogue planet crashing into us, a 'killer' solar flare or geomagnetic reversal -- where Earth spins out of control -- are just some of the ways we might meet our makers, however despite hundreds of years of apocalyptic warnings none has come true.
But serious science loves a good doomsday theory. Last September the annual Ig Nobel prizes were awarded in Harvard University's Sanders Theatre to honour scientific achievements "that first make people laugh, then make them think".
The winner of the psychology prize was a Norwegian researcher for trying to understand why, in everyday life, people sigh.
The mathematics prize for "teaching the world to be careful when making mathematical assumptions and calculations" was shared by six people who all predicted the end of the world using a mathematical formula -- Dorothy Martin, who was told by aliens the world would end in a great flood in 1954; TV evangelist Pat Robertson, who predicted judgment day in 1982; and Elizabeth Clare Prophet, who reckoned nuclear war would kill everyone in 1990. All were American. Also honoured were Lee Jang Rim of Korea, Credonia Mwerinde of Uganda, and Harold Camping, also of the US.
Of course, none turned out to be accurate but it's not the predicted end of days we need to worry about. There's been five major extinction episodes in Earth's history which probably took every living thing on the planet by surprise.
They include the Permian extinction about 250 million years ago which finished the dinosaurs and which may have been caused by a meteor crashing to earth.
We'll never know, but here's a cheery thought -- we could go at any time.
Space is inhabited by millions of asteroids, many in Earth-crossing orbits, and one the size of a house could destroy a city. As Bill Bryson notes in his Short History of Nearly Everything, in 1991 one was spotted after it had missed Earth by just 170,000km -- "in cosmic terms the equivalent of a bullet passing through one's sleeve without touching the arm".
And there's hazards on the planet too. Yellowstone National Park in the US, home of geysers and bubbling mud pools, is in fact a 'supervolcano' -- a mighty simmering cauldron of magma almost 70km wide. It erupts about every 600,000 years. It last went 630,000 years ago, showering much of the US and Canada with ash. It's overdue.
However, there's no point in worrying. We do have the certainty of knowing the world will end in about four billion years when the sun has depleted its supply of hydrogen and it swells like a balloon. Then Earth will definitely be toast.
That's a comforting thought.