Sept. 20, 2017: Various people are "predicting" that world will end Oct. 23 when another planet collides with Earth. The planet in question, Niburu, doesn't exist, so there will be no collision. As you can see from the Q&A below, the story of Niburu has been around for years (as has the "days of darkness" tale) and is periodically recycled into new apocalyptic fables.