When considering what might cause us grief in 2012, few if any researchers consider the start of the Mayan Long Count calendar to have any importance. This is surprising, because the reason for the calendar beginning on August 11 3114BC might contain clues about 2012 itself. After all, the Mayan culture did not exist 5,000 years ago, so either they randomly chose an ancient date on a whim, or an earlier civilization was behind the calendar, and they knew something important occurred on that date.
What could happen in 3114BC, and also in 2012AD? No civilization has lasted that long, so they are unlikely to be man-made events. Any natural events that occur so infrequently on Earth are virtually impossible to predict (volcanic eruptions for example). So that leaves us with astronomical events. The astrology of the pair of dates has been well studied, so we can rule out alignments of the stars and planets. That leaves the Sun, which we barely understand today, and comets. Is there a comet with a periodicity of 5000 years, due to return in 2012? Without any evidence from 3114BC it is impossible to say. Given that we are now near the end of the Mayan 5th age, could their calendar be designed to cover five orbits of a comet? And end catastrophically in 2012?
Most people have not heard of Comet Caesar (it doesn't even have a Wikipedia entry), and hopefully this will remain so. However, if we are to suffer a terrible tragedy in 2012, it is currently my leading candidate, and the purpose of this article is to explain why.