There is so much astonishing historical evidence about the human race, where we came from, that it's inconceivable that we not know and understand more than we do about ourselves.
According to Sitchin's interpretation of Mesopotamian iconography and symbology, outlined in his 1976 book The 12th Planet and its sequels, there is an undiscovered planet beyond Neptune that follows a long, elliptical orbit, reaching the inner solar system roughly every 3,600 years.
This planet is called Nibiru (although Jupiter was the planet associated with the god Marduk in Babylonian cosmology). According to Sitchin, Nibiru (whose name was replaced with MARDUK in original legends by the Babylonian ruler of the same name in an attempt to co-opt the creation for himself, leading to some confusion among readers) collided catastrophically with Tiamat (a goddess in the Babylonian creation myth the Enûma Eliš), which he considers to be another planet once located between Mars and Jupiter. This collision supposedly formed the planet Earth, the asteroid belt, and the comets. Sitchin states that when struck by one of planet Nibiru's moons, Tiamat split in two, and then on a second pass Nibiru itself struck the broken fragments and one half of Tiamat became the asteroid belt. The second half, struck again by one of Nibiru's moons, was pushed into a new orbit and became today's planet Earth.
According to Sitchin, Nibiru (called "the twelfth planet" because, Sitchin claimed, the Sumerians' gods-given conception of the Solar System counted all eight planets, plus Pluto, the Sun and the Moon) was the home of a technologically advanced human-like extraterrestrial race called the Anunnaki in Sumerian myth, who Sitchin states are called the Nephilim in Genesis. He wrote that they evolved after Nibiru entered the solar system and first arrived on Earth probably 450,000 years ago, looking for minerals, especially gold, which they found and mined in Africa. Sitchin states that these "gods" were the rank-and-file workers of the colonial expedition to Earth from planet Nibiru.
Sitchin wrote that Enki suggested that to relieve the Anunnaki, who had mutinied over their dissatisfaction with their working conditions, that primitive workers (Homo sapiens) be created by genetic engineering as slaves to replace them in the gold mines by crossing extraterrestrial genes with those of Homo erectus. According to Sitchin, ancient inscriptions report that the human civilization in Sumer, Mesopotamia, was set up under the guidance of these "gods", and human kingship was inaugurated to provide intermediaries between mankind and the Anunnaki (creating the "divine right of kings" doctrine). Sitchin believes that fallout from nuclear weapons, used during a war between factions of the extraterrestrials, is the "evil wind" described in the Lament for Ur that destroyed Ur around 2000 BC. Sitchin states the exact year is 2024 BC. Sitchin says that his research coincides with many biblical texts, and that biblical texts come originally from Sumerian writings.
If you like really weird reading material [like I do! LMAO] here is a page full of Anunnaki