Nibiru is a name from Babylonian astronomy, Nēberu in Akkadian, meaning "crossing" or "ford", that ancient texts attach to the god Marduk and to a celestial position usually identified with the planet Jupiter. The idea of Nibiru as a hidden twelfth planet on a 3,600-year orbit, home of the Anunnaki, comes from Zecharia Sitchin's 1976 book The 12th Planet, not from the tablets themselves. Modern astronomy has found no such planet, although astronomers are searching for a very different distant world nicknamed Planet Nine.
Nibiru sits where three conversations are often blurred together: what Mesopotamian scribes actually wrote, what ancient-astronaut writers built on top of those texts, and what telescopes and orbital mechanics can test. Separating them does not settle every question about the ancient world, but it shows which claims rest on cuneiform, which rest on interpretation, and which were tied to doomsday dates that have already passed. That clarity is the foundation for any serious look at the [Anunnaki and Sumerian material](/topics/anunnaki).
What does Nibiru mean in the ancient texts?
In the cuneiform record, Nibiru (Nēberu) is a term of astronomy and theology, not a description of a wandering planet. The word comes from the Akkadian verb ebēru, "to cross", and carries the sense of a crossing place or ferry. Babylonian astronomers used it for a point or a star associated with Marduk, the patron god of Babylon.
The clearest astronomical use comes from MUL.APIN, a compendium of star lore and calendar rules whose surviving copies date to the first millennium BCE, edited by Hermann Hunger and David Pingree in 1989. There, Neberu is connected with Marduk's star, which most Assyriologists identify with Jupiter, and with its position as it crosses the sky. Some scholars read the term as marking a crossing point on the ecliptic rather than a single body. Either way, it describes something visible in the ordinary night sky.
Nothing in these texts gives Nibiru a 3,600-year orbit, describes it as inhabited, or predicts a return that threatens Earth.
What the Enuma Elish actually says about Nibiru
The Enuma Elish mentions Nēberu as part of Marduk's ordering of the cosmos. The Babylonian creation epic, written on seven tablets (see [the Enuma Elish explained](/the-enuma-elish-explained-seven-tablets-of-creation)), tells how Marduk defeats Tiamat, the primordial sea, and splits her body to form sky and earth.
In tablet V, after the battle, Marduk sets up stations in the heavens for the great gods, fixes the constellations and the calendar, and establishes the position of Nēberu to fix the bands or relationships of the stars. In tablet VII, where the assembled gods proclaim Marduk's fifty names, Nēberu is one of them: the god who holds the crossings of heaven and earth. W. G. Lambert's translation in Babylonian Creation Myths (2013) and Stephanie Dalley's in Myths from Mesopotamia render both passages in these astronomical and theological terms.
Tiamat in the epic is a goddess of the salt waters and mother of the first generation of gods. Reading her as a planet is an interpretive move made in the twentieth century, not a feature of the Babylonian text.
Where the 3,600-year planet comes from
The Nibiru most people have heard of was introduced by Zecharia Sitchin in The 12th Planet (1976). Sitchin argued that the Sumerians knew of twelve members of the solar system, counting the Sun and Moon, and that the twelfth was Nibiru, a large planet on a long elliptical orbit that returns to the inner solar system every 3,600 years.
In his reconstruction, Nibiru was the home of the Anunnaki, whom he presented as an advanced people rather than gods (see [who were the Anunnaki](/who-were-the-anunnaki-sumerian-texts-vs-ancient-astronaut-theory)). He read the Enuma Elish as a coded account of a real astronomical event: Nibiru, which he identified with Marduk, entering the solar system and colliding with a planet he called Tiamat, whose remains formed Earth and the asteroid belt.
The 3,600-year figure comes from the Sumerian number sign šar (often written shar), which stands for 3,600 in the base-60 counting system. Sitchin took it to be the length of one Nibiru year. He also pointed to an Akkadian cylinder seal in Berlin's Vorderasiatisches Museum, catalogued VA 243, which he read as a picture of the Sun ringed by its planets.
How scholars have responded to Sitchin
Assyriologists and historians have almost unanimously rejected Sitchin's readings. Their main objections are that šar is a number and a word for totality, not a unit of orbital time; that no tablet describes Nibiru as a planet beyond the known planets; and that his translations of key Sumerian and Akkadian terms do not match standard reference works such as the Chicago Assyrian Dictionary.
On the seal, critics including the late Michael Heiser argued that the central symbol on VA 243 is a standard star emblem, not the Sun, which Mesopotamian art typically showed with a different, distinctive symbol. Ronald H. Fritze's Invented Knowledge (2009) places Sitchin within a longer tradition of alternative history that has found a large public readership while failing to persuade specialists.
None of this erases Sitchin's influence. His books sold widely, introduced many readers to Sumerian culture, and sent people back to the primary sources to check for themselves. For an overview of what those sources are and what they contain, see [the Sumerian tablets explained](/the-sumerian-tablets-explained-what-they-are-and-what-they-say).
How Nibiru became a doomsday prediction
The doomsday version of Nibiru did not come from Sitchin. It came from Nancy Lieder, who launched the website ZetaTalk in 1995 and said she received messages from extraterrestrials. Lieder linked a Planet X to a catastrophic pass by Earth in 2003. When nothing happened, the date moved to December 2012, where it merged with popular claims about the end of a Maya calendar cycle.
The 2012 wave grew large enough that NASA published public explainers stating that no such planet exists, and NASA scientist David Morrison answered a steady stream of questions from worried members of the public. The date passed without incident. In 2017 the writer David Meade tied a Nibiru appearance to September 23 of that year. That date passed too.
The pattern matters for anyone weighing a new Nibiru claim: every specific date offered so far has been falsified by the calendar.
What astronomers mean by Planet X and Planet Nine
In astronomy, Planet X has a separate and older history. In the early twentieth century Percival Lowell searched for an unseen planet beyond Neptune that he believed was disturbing the orbit of Uranus; the X simply meant unknown. Clyde Tombaugh found Pluto at Lowell Observatory in 1930, but Pluto proved far too small to cause the disturbances. Later measurements, refined by Voyager 2's 1989 flyby of Neptune, showed the discrepancies came from a small error in Neptune's estimated mass, not from a hidden planet.
The modern successor is Planet Nine. In 2016 Konstantin Batygin and Michael Brown of Caltech proposed, in the Astronomical Journal, that a planet of roughly five to ten Earth masses orbiting hundreds of astronomical units from the Sun could explain the clustered orbits of several extreme trans-Neptunian objects. As of 2026 it has not been observed, and some astronomers argue that the clustering may reflect where and how surveys have looked rather than a real planet.
Planet Nine, if it exists, would never come near the inner solar system. It is not Nibiru under a new name.
Can a Nibiru-type planet be hiding?
A large planet that swings through the inner solar system every 3,600 years is ruled out by observation. Kepler's third law ties orbital period to distance: a 3,600-year period implies an average distance of roughly 235 astronomical units, so such a planet could never be more than about 470 AU from the Sun. An object of that size and that proximity would already have been detected.
The Wide-field Infrared Survey Explorer (WISE) mapped the entire sky in infrared light, where a planet's own heat makes it stand out. Kevin Luhman's 2014 analysis of WISE data found no Saturn-sized object out to 10,000 AU, far beyond the farthest point a 3,600-year orbit allows. A massive planet also leaves gravitational fingerprints. The orbits of the known planets and of spacecraft are tracked precisely enough that an intruder on a 3,600-year cycle would show up in the data long before it arrived, and nothing of the kind appears.
For readers drawn to the larger questions of how the cosmos is structured, the [holographic universe hub](/topics/holographic-universe) covers the physics side of those debates.
Billy Carson's reading
Billy Carson treats Nibiru as Sitchin's reading of the celestial battle in the Enuma Elish, rather than as a planet described in the tablets themselves. He has discussed what he frames as the myths and misconceptions surrounding the search for Nibiru, separating the ancient story from the doomsday predictions and rumours that later attached to it.
Carson's wider work on the Anunnaki engages with ancient-astronaut interpretations of Sumerian and Babylonian texts, and he presents them as a way of questioning conventional accounts of early civilisation. Readers should take that framing as his interpretation. The astronomical record set out above stands on its own, and his approach invites audiences to compare the interpretations with the texts and the evidence. His talks on these themes can be found in [Best of Billy Carson](/watch/best-of-billy-carson) on 4BK TV.
Watch, read and go deeper
Start with [Best of Billy Carson](/watch/best-of-billy-carson) on 4BK TV for his discussions of the Anunnaki and the Nibiru debate. For the primary text, read [the Enuma Elish explained](/the-enuma-elish-explained-seven-tablets-of-creation), then look at tablets V and VII in Lambert's or Dalley's translation to see how Nēberu is actually used. The [Anunnaki and Sumer topic hub](/topics/anunnaki) gathers the related articles on Mesopotamian texts and the ancient-astronaut debate in one place.
Frequently asked questions
Is Nibiru mentioned in ancient Mesopotamian tablets?
Yes, the term Nēberu appears in Babylonian texts written in Akkadian, including the Enuma Elish and the astronomical compendium MUL.APIN. It refers to a crossing point or star associated with Marduk, usually identified as Jupiter. No tablet describes it as a hidden planet with a 3,600-year orbit.
Is Nibiru the same as Planet X?
Popular culture uses the names interchangeably, largely because of the 2003 and 2012 doomsday predictions. In astronomy, Planet X originally meant Percival Lowell's hypothetical planet beyond Neptune. The current candidate, Planet Nine, would have an orbit completely different from the one Sitchin described for Nibiru.
Has NASA confirmed Nibiru?
No. NASA has stated publicly that Nibiru does not exist, including in explainers published ahead of December 2012. Infrared sky surveys such as WISE have found no large undiscovered planet in the regions where a Nibiru-type body would have to be.
What is Planet Nine?
Planet Nine is a hypothesised planet of roughly five to ten Earth masses, proposed by Konstantin Batygin and Michael Brown in 2016 to explain the clustered orbits of distant objects beyond Neptune. It would orbit hundreds of astronomical units from the Sun and has not been observed as of 2026.
Why did Sitchin say Nibiru's orbit lasts 3,600 years?
Sitchin took the Sumerian number šar, which equals 3,600 in the base-60 counting system, to be the length of Nibiru's year. Scholars point out that the texts use šar as a number and never as an orbital period.
Sources and further reading
- Zecharia Sitchin, The 12th Planet (1976)
- W. G. Lambert, Babylonian Creation Myths (Eisenbrauns, 2013)
- Stephanie Dalley, Myths from Mesopotamia (Oxford University Press, 1989)
- Hermann Hunger and David Pingree, MUL.APIN: An Astronomical Compendium in Cuneiform (1989)
- Konstantin Batygin and Michael E. Brown, Evidence for a Distant Giant Planet in the Solar System, Astronomical Journal (2016)
- Kevin L. Luhman, A Search for a Distant Companion to the Sun with the Wide-field Infrared Survey Explorer, Astrophysical Journal (2014)
- Ronald H. Fritze, Invented Knowledge: False History, Fake Science and Pseudo-Religions (2009)
