Space.com says: Linked to the closing of the Mayan calendar, in 2012 various rumors spread about how the world might end. One of them was Nibiru, a supposed planet that, according to some, would collide with Earth at the end of that year. But, despite the rumors, there is no scientific evidence to support the existence of the alleged planet and, of course, our planet survived 2012 without absorbing a massive impact.

Several bloggers have linked Nibiru to NASA. Because of this alleged connection, space agency officials issued a statement claiming that no large planet was coming to destroy Earth in 2012. What follows is the real science and history of this supposed rogue planet, with reference to a real object, Comet Elenin, which somehow got mixed up in the whole mess.

However, the existence of unorbiting planets is a reality, and what's more, they add up to a huge amount in the cosmos, so many that they cannot even be measured in their number.

A rogue planet (also called a free-floating, interstellar, nomadic, orphan, starless, unbound or wandering planet) is an interstellar object of planetary mass that is not gravitationally bound to any star or brown dwarf. Wayward planets originate in planetary systems in which they form and are subsequently ejected. They can also form on their own, outside a planetary system. In the Milky Way alone there may be billions to trillions of wayward planets, a range that the upcoming Nancy Grace Roman Space Telescope will likely be able to narrow down.

Nibiru, without being a rogue planet, may well be within the range of planets not yet discovered by NASA, as we can appreciate with those planets beyond the Kuiper belt, which is where it is gravitating around the sun at the moment.