
According to the theories on the internet, the calendar used by the ancient civilisation of the Mayans is due to come to an end in December 2012.
Luckily for conspiracy theorists, this coincides neatly with predictions by an obscure sci-fi author, who wrote about the ancient Mesopotamian civilization of Sumer, that a planet named Nibiru will collide with the Earth on that date.

The Mayan calendar ends in 2012, but Dr Morrison said this did not mean the world would end
Fears have been further inflamed by an apocalyptic film called '2012' starring John Cusack, which is out this November. A quick search on Amazon reveals there are 175 books listed that deal with 2012 doomsday.
First off Dr Morrison dismisses the possibility that the planet Nibiru even exists.
He writes: 'The bottom line is that Nibiru is a myth, with no basis in fact.
'To an astronomer, persistent claims about a planet that is "nearby" but “invisible” are just plain silly.'
And Dr Morrison laughs off suggestions that the government has been complicit in hiding its existence from the public.
'Even if they wanted to, the government could not keep Nibiru a secret,' he says.
'If it were real, it would be tracked by thousands of astronomers, amateurs as well a professional. These astronomers are spread all over the world.
'I know the astronomy community, and these scientists would not keep a secret even if ordered to. You just can’t hide a planet on its way to the inner solar system!'
He also addresses the concerns of those who worry that the Mayan calendar is due to end in 2012.
'Ancient calendars are interesting to historians, but they cannot match the ability we have today to keep track of time, or the precision of the calendars currently in use.
'The main point, however, is that calendars, whether contemporary or ancient, cannot predict the future of our planet or warn of things to happen on a specific date such as 2012.
'I note that my desk calendar ends much sooner, on December 31 2009, but I do not interpret this as a prediction of Armageddon. It is just the beginning of a new year.'
He added although many believe prophecies by the sixteenth century seer Nostradamus predict the end of the world in 2012, there is no evidence he has correctly predicted anything.
He also tackles the belief circulating on some internet forums that an alignment of planets in our galaxy the Milky Way could in some way disrupt the Earth's gravitational field or reverse the Earth's rotation.