"The story begins several billion years ago when Earth was very young. It was then a large planet called Tiamat, and it rotated around the Sun between Mars and Jupiter. Ancient Earth had a large moon, which their records say was destined to become a planet itself someday in the future.
According to the records, there was one more planet in our solar system that we are only vaguely aware of in these modem times. The Babylonians called this planet Marduk, and this name has sort of stuck, but the Sumerian name for it was Nibiru. It was a huge planet that spun retrograde compared to the other planets. The other planets are in a more or less flat plane moving in one direction, but Nibiru moves in the other direction, and when it comes close to the other planets, it passes through the orbit of Mars and Jupiter [Fig. 3-8].
They said that it passes through our solar system every 3600 years, and when it came, it was usually a big event in our solar system. Then it would go way out past the outer planets and disappear from our sight. NASA, by the way, has probably found this planet. At least it is the most probable possibility. They used two satellites and located it at an enormous distance from the Sun. It’s definitely there, but the Sumerians knew about it thousands of years ago! Then, according to the records, as fate would have it, on one orbital pass Nibiru came in so close that one of its moons struck Tiamat (our Earth) and tore about half of it off—just ripped this planet right in half. According to the Sumerian records, this big chunk of Tiamat, along with her major moon, got knocked off course, went into orbit between Venus and Mars, and became Earth as we now know it. The other chunk broke into a million pieces and became what the Sumerian records call “the hammered bracelet,” which we call the asteroid belt between Mars and Jupiter. This is another point astronomers have marveled at. How did they know about the asteroid belt, because you can’t see it with the naked eye?
This is how far back the Sumerian records go. The records continue to talk about earlier events, until at one point they tell more about Nibiru. It was inhabited by conscious beings called the Nefilim. The Nefilim are very tall: the females are about 10 to 12 feet and the males are about 14 to 16 feet. They’re not immortal, but their lifetime is about 360,000 Earth years, according to the Sumerian records. Then they die."
― Drunvalo Melchizedek, The Ancient Secret Of The Flower Of Life Vol. 1, p. 83-84