Nibiru, also known as Planet X, is a supposed planet that was popularized by Zecharia Sitchen in his book, "The Twelfth Planet". Nibiru is said the be the planet of a group of extraterrestrial beings known as the Anunnaki. It is said that Nibiru orbits the sun every 3,600 years which is why we can't currently don't see it, even though many people claim we can see it and NASA is covering it up.

Many people say Nibiru is set to return near to the earth in the coming future. When and at what time is up for debate. Some said it was supposed to happen in 2012, others say it is closer to the year 2160. People say that the Anunnaki will be returning on Nibiru and that they will be back to check up on the progress of humans.