"Why did the government make an announcement not to worry about 2012?... Is this a conspiracy? And if NASA is not worried about Dec 21, why did the head of NASA make a video warning NASA employees to prepare for disaster?" -- question on NASA's Ask an Astrobiologist

Being a lazy person at heart, I am always impressed by people who devote a great deal of time and effort to a cause. And so it is with the thousands of inquisitors to NASA’s Ask an Astrobiologist web page about the end of the world, which is supposed to take place at midnight on Friday, or perhaps at 6:12 am EST, the precise moment of the winter solstice.

The accumulated evidence for this event is vast, so I’ll summarize: the current era as depicted on the Mayan calendar runs out on Friday, which happens to coincide with the winter solstice, which falls on a weirdly symmetrical date, 12-21-12. It also happens to be the day the planet Nibiru is expected to collide with Earth. Contemporary astronomers have somehow managed to overlook this planet, but the ancient Sumerians knew better, according Zecharia Sitchin, the late author whose ideas on the matter have been thoroughly and repeatedly discredited.

The good news here—though we have to stretch for it—is that the end of the world hysteria has sent thousands of people to seek out scientific opinion, even if to argue against it. And it has given the writers and contributors of Scientific American plenty of excuses to sort fact from fiction. Over the past year we have published numerous stories on all angles of the apocalypse. I for one am going to miss this story when the sun rises on Dec. 22 and we all have to go on with our lives as usual.

In anticipation of the end of the end, we have assembled our past stories about potentially world-ending events into an in-depth report. If you can't bring yourself to belief in Nibiru, we supply many more serious reasons to worry about planetary disaster. We could face severe disruption to weather systems from climate change. We could get struck by a giant asteriod (though, to be clear, the chance of that happening on Friday is just about zero). And nuclear weapons still pose an existential threat.

We also try and explain why we're suckers for stories of the apocalypse, and use the numerology reasoning as a teachable moment about math. And we laud the tireless heros for truth at NASA, who field question after question with an almost comical weariness. “NASA has been answering questions from the public about doomsday 2012 for several years… but most media did not notice,” writes David Morrison, Astrobiology Senior Scientist. A recent NASA announcement urging employees to prepare for disaster concerned plausible events like hurricanes and so forth rather than Armageddon. “It is absurd for the conspiracy cranks to interpret this as a warning about Nibiru or other doomsday fantasies."

And starting at midnight tonight we have a special End of the World Sale on digital subscriptions: $12.21 for an entire year. Only optimists need apply.

In case you want to indulge your fears, listen to Steve Mirksy’s podcast on what the world would be like without us.