The date: December 22, 2012. If you’re watching this, the world didn’t end yesterday, a Nasa video begins. The US space agency goes on to explain why the commotion over the purported Mayan prophecy is all for naught. “The whole thing was a misconception from the very beginning,” Dr John Carlson, director of the Center for Archaeoastronomy , says in the video. “The Maya calendar did not end on December 21, this year, and there were no Maya prophecies foretelling the end of the world on that date.” The video goes on to explain the cyclical calendar used by the ancient Maya. And if that’s not enough, Nasa scientists answer frequently asked questions for doomsday believers.