By Stephen Petranek

So, the world hasn’t come to an end yet. But the insecurities and fears about the so-called Mayan Calendar prediction that Earth as we know it will cease to exist today has created such a ruckus that Michigan officials closed 33 schools in preparation and NASA has devoted many web pages to it.

Could it be true? Well, yes, on any given day our world could come to a sudden end. (I outlined 10 ways it could happen in my talk from TED2002, “Countdown to Armageddon.”) Is it likely? No.

NASA, in trying to be reassuring, is delivering a strange but accurate message: No, they don’t see any threats that are imminent, but they’re actually hedging their bets about the near future. They don’t see any large asteroids on the horizon, for example, but a smallish asteroid that missed Earth by three radiuses last May wasn’t detected until it was within hours of us. What NASA is not saying is that finding incoming asteroids is a tricky business and that most are found by amateurs who have time to look for them. It’s still possible that a huge asteroid, perhaps months from collision, could be on its way toward us but remains undetected.

(See also: TED Speaker Phil Plait’s essay today on The Huffington Post, “How to Defend Earth From Asteroids.”)

On other fronts, NASA says the sun isn’t very agitated today, so a solar flare that might engulf Earth is unlikely, but it does mention that the next two years will be the peak of our 11-year solar cycle.

The space agency pooh-poohs a supervolcanic eruption with massive lava flows, — the sort of thing that created the Indian subcontinent — as extremely unlikely, which it surely is, but acknowledges that eruptions occur on Earth with regularity and that we find them remarkably mysterious. Read that as “unpredictable.”

So my suggestion is that you go about your last-minute holiday shopping with abandon. The forecast: disaster unlikely. But don’t dismiss Mother Nature. It is an absolute certainty that an asteroid as large as the one that took out the dinosaurs will hit Earth. We just don’t know when.

Either way, you now have plenty of time on your hands. Spend some it watching these four doomsday TEDxTalks — some humorous, some horrifying.

6 reasons why you want to believe doomsday is coming: Tommy Calloway at TEDxAsheville
Doomsday prophecies have a terrible track record. So why does anyone believe in them? Comedian Tommy Calloway has six answers.

The end is nigh: John Hodgman at TEDxMidwest
In this unusual talk, “deranged millionaire” John Hodgman shares his plan for the coming apocalypse and implores you to adopt his survival strategies, including stockpiling mayonnaise and moving into a houseboat that can float on rivers of blood.

9 biggest weather disasters in the next 30 years: Jeff Masters at TEDxBermuda
In a talk given earlier this year, meteorologist Jeff Masters presented the nine most devastating natural disasters likely to happen in the United States in the next thirty years. Number six happened in October.

How to defend Earth from asteroids: Phil Plait at TEDxBoulder
65 million years ago, an asteroid wiped out the dinosaurs. Can we save ourselves from the same fate? Astronomer Phil Plait discusses the science of asteroids and what we can do to prevent a catastrophic impact.

Also fun: The Wall Street Journal‘s round-up of apocalypse television programming for tonight.

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