According to Sitchin, Nibiru collided catastrophically with Tiamat, who he considered to be another planet located between Mars and Jupiter. This collision formed the planet Earth, the asteroid belt, and the comets. Sitchin claims 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.