Nibiru cataclysm is a supposed disastrous encounter between the Earth and a large planetary object (either a collision or a near-miss) which certain groups believe will take place in the early 21st century. Believers in this doomsday event usually refer to this object as Planet X or Nibiru. The idea that a planet-sized object will collide with or closely pass by Earth in the near future is not supported by any scientific evidence and has been rejected as pseudoscience and an Internet hoax by astronomers and planetary scientists.