Dec. 21, 2012, has long been rumored to be the day of the Mayan apocalypse, when Earth comes to its inglorious end. The good folks at NASA want you to know that isn't going to happen.

In fact, NASA is so confident that it recently published a video that appears as if it were intended to be aired on Dec. 22. Titled "The World Didn't End Yesterday," the four-minute clip explains how the idea of the Mayan apocalypse was a huge hoax and how the rumors began. A commenter on YouTube jokes, "The correct title for this video: Told ya so!—Love, NASA."

Time magazine reports that the space agency has been besieged with questions from citizens worried that their lives are about to end. NASA is taking the fears seriously, not because there is any danger, but because irrational fears can sometimes lead to irrational and dangerous actions.

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NASA's official site features an area dedicated to debunking the claims. "The world will not end in 2012," NASA writes. "Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012."

NASA experts go on to explain the origins of the hoax. "The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth. This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012 and linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012—hence the predicted doomsday date of Dec. 21, 2012."

Nibiru, by the way, is not a real planet. If it were, NASA says the agency "would have been tracking it for at least the past decade, and it would be visible by now to the naked eye."

Translation: The world isn't going to end. You still have to finish your holiday shopping. You still have to come up with something fun to do on New Year's Eve. Sorry.