Information about Nibiru comes from the Sumerians and the writing and artifacts they, and other ancient people, left behind. The core premise he has made in his writings is that there is a 10th Planet (again, including Pluto) in our solar system with an elliptical orbit of about 3,600 of our years. People from Nibiru came to Earth and discovered the gold they needed to help repair their atmosphere and they began mining it. Much of the knowledge of these ancient people, which they knew because the Anunnaki (those who from heaven to Earth came) told them, has come true, including the color and size of Neptune and Uranus, and the very existence of the outer planets, long before our telescopes could find them.