Nibiru, in Babylonian Astronomy translates to "Planet of Crossing" or "Point of Transition", especially of rivers, i.e. river crossings or ferry-boats, a term of the highest point of the ecliptic, i.e. the point of summer solstice, and its associated constellation. The establishment of the Nibiru point is described in tablet 5 of the Enuma Elish. Its cuneiform sign was often a cross, or various winged disc. The Sumerian culture was located in the fertile lands between the Euphrates and Tigris rivers, at the southern part of today's Iraq.
As the highest point in the paths of the planets, Nibiru was considered the seat of the summus deus who pastures the stars like sheep, in Babylon identified with Marduk. This interpretation of Marduk as the ruler of the cosmos was identified as an early monotheist tendency in Babylonian religion by Alfred Jeremias.
The work of Zecharia Sitchin has garnered much attention among ufologists, ancient astronaut theorists and conspiracy theorists. He claims to have uncovered, through his retranslations of Sumerian texts, evidence that the human race was visited by a group of extraterrestrials from a distant planet in our own Solar System.
Part of his theory lies in an astronomical interpretation of the Babylonian creation myth, the Enuma Elish, in which he replaces the names of gods with hypothetical planets. However, since the principal evidence for Sitchin's claims lies in his own personally derived etymologies and not on any scholarly agreed interpretations, his theories remain at most pseudoscience to the majority of academics.
Sitchin's theory proposes the planets Tiamat and Nibiru. Tiamat supposedly existed between Mars and Jupiter. He postulated that it was a thriving world in a much differently shaped solar system, with jungles and oceans, whose orbit was disrupted by the arrival of a large planet or very small star (less than twenty times the size of Jupiter) which passed through the solar system between 65 million and four billion years ago. The new orbits caused Tiamat to collide with one of the moons of this object, which is known as Nibiru. The debris from this collision are thought by the theory's proponents to have variously formed the asteroid belt, the Moon, and the current inclination of the planet Earth.
To the Babylonians, Nibiru was the celestial body or region sometimes associated with the god Marduk. The word is Akkadian and the meaning is uncertain. Because of this, the planet Nibiru is sometimes also referred to as Marduk. Sitchin hypothesizes it as a planet in a highly elliptic orbit around the Sun, with a perihelion passage some 3,600 years ago and assumed orbital period of about 3,750 years; he also claims it was the home of a technologically advanced human-like alien race, the Anunnaki, who allegedly visited Earth in search of gold. These beings eventually created humanity by genetically crossing themselves with extant primates, and thus became the first gods.
Beginning in 1995, websites such as ZetaTalk have identified Nibiru or "Planet X" as a brown dwarf currently within our planetary system, soon to pass relatively close to Earth affecting Earth's magnetics and causing catastrophic damage. Sitchin disagrees as do I.
Natural disasters are accelerating exponentially without Nibiru or aliens - but then again Nibiru takes us back to the Sumerian Gods creating a biogenetic experiment called humans (slave labor as we have no powers down here) to mine (caves, mind, consciousness) for gold (alchemy of consciousness) -- returning every 3,600 years -- 12 around 1 X 3 (36=9=closure) - and on and on with myth, math, and metaphor.
Creator Gods and Goddesses take us to ancient alien theory -- they create human biogenetic experiments over and over again, each one more evolved -> then wipe them out with floods (collective unconsciousness) and recreate once again. We certainly seem to be living in biblical flood times now, if you believe that ever happened.
Beyond that we have the true nature of it all - the consciousness hologram which creates the aliens who create humans - the truth revealed at the end of the experience/experiment. Alas, it is the hologram that ends taking with it the knowledge of everything that has transpired within - much like the alien artifact in the Steven Spielberg's mini-series Taken about gray aliens who created a biogenetic experiment combining their DNA with humans to create a more evolved life form. Sound familiar? It also parallels Hitler and the Nazi biogenetic experiments - the Master Plan.