Planet X aka Nibiru

Zecharia Sitchin (born 1922)[1] is an author of books promoting an explanation for human origins involving ancient astronauts. Sitchin attributes the creation of the ancient Sumerian culture to the Anunnaki, which he claims to be a race of extra-terrestrials from a hypothetical planet beyond Neptune called Nibiru, which he believes to be in an elongated, elliptical orbit in the Earth's own Solar System, asserting that Sumerian mythology reflects this view.
Sitchin's speculations are entirely discounted by professional scientists, historians, and archaeologists, who note many problems with his translations of ancient texts and with his understanding of physics,[2] categorizing his work as pseudoscience.