Nibiru, also referred to as Planet X or the twelfth planet, is thought to be a distant planet in our solar system with a 3600-year orbit around the sun. The name Nibiru means "planet of the crossing" according to translations of ancient Sumerian writings.

The idea of the existence of Niribu has gained attention in recent years, following a hypothesis Zecheria Sitchin came to after analyzing ancient Sumerian writings documenting stories and pictures about man living among Gods on the Earth. According to this theory, the planet Nibiru was involved in a cataclysmic collision with a planet located between Mars and Jupiter, called Tiamat. It is said that this extraordinary event created the planet Earth, as well as the asteroid belt and the Moon.

Sitchin claims to have discovered evidence of artifacts including stone tablet pictures that depict visits by advanced alien settlers, called Anunnaki. It is said that these extra-terrestrials who lived on the planet Nibiru, survived the catastrophic encounter with Earth around 3,600 years ago. They then arrived on Earth searching for gold dust particles to help rebuild the abrupt demise of their atmosphere. According to Sitchin's analysis, these extra-terrestrial guests genetically engineered the human species and used them as slaves in their gold mines.

There are many researchers who have predicted a date when they expect Nibiru’s wide elliptical orbit to once again pass by Earth. This date coincides with the end of the Mayan calendar and Winter Solstice — 21 December 2012. On this date, it is expected that the Earth, Sun and center of the Milky Way galaxy will align causing a dramatic orbital interruption on Earth's neighboring planets and catastrophic consequences for life on Earth.

While most consider it a Sumerian myth, and maybe even just another impressive tale, there are many believers who embrace Sitchin's claims and anxiously await the return of the planet Nibiru. Scientists argue against the possibility of a planet with a such a unique orbit and overwhelmingly consider Sithin's allegations to be false. The existence of Nibiru and it's inhabitants, the Anunnaki, are not supported by scientific evidence.