According to Sitchin, ancient Sumerian clay tablets reveal that gods from another planet (Nibiru, which orbits our Sun every 3,600 years) arrived on Earth some 450,000 years ago and created humans by genetic engineering of female apes. In 1976, Sitchin published his first book on ancient astronauts, The 12th Planet. This groundbreaking title pooled together his research into ancient tablets and texts with his theories about alien visitors who created human life on earth long ago. It was a groundbreaking title and the first of the Earth Chronicles volumes, a set which would eventually span 7 books. It follows a slow elliptical orbit somewhere beyond Neptune, and crosses into the inner solar system ever 3,600 years or so. This planet may be referred to as Marduk or Planet Nibiru. A collision between Nibiru and Tiamat (another hypothesized planet which no longer exists—if it ever did) created the Earth as well as the asteroid belt and the comets. This is the “twelfth planet” (the sun and moon are counted along with Pluto). Nibiru is home to a race of extraterrestrials. These are the Anunnaki of Sumerian lore, and may also be the Nephilim as referenced in Genesis. The Anunnaki visited earth during the times of the ancient Sumerians. Searching for gold to sustain their homeworld, they needed workers to help them mine it. For this purpose, they genetically engineered a slave race—humans. This corresponds with the Mesopotamian story involving Enki and Enlil. 600 Anunnaki lived on Earth and 300 on Mars (resupply station - atmosphere became uninhabitable).https://www.annunaki.org/who-was-zecharia-sitchin/