An article by R. Harrington in The Astronomical Journal dated October 1988 supplied the details of continuing mathematical modeling of this planet. The article suggested the mysterious planet was three to four times the size of Earth, and its position was three times further from the Sun than Pluto. Mathematical modeling also suggested that Planet X had an extreme elliptical orbit of 30 degrees. A NASA/ARC press release published in Newsweek on July 13, 1987 disclosed that "an eccentric 10th planet may - or may not - be orbiting the Sun." The article stated that NASA research scientist John Anderson "has a hunch Planet X is out there, though nowhere near the other nine." The article concluded, "if he is right, two of the most intriguing puzzles of space science might be solved: what caused mysterious irregularities in the orbits of Uranus and Neptune during the 19th Century? And what killed off the dinosaurs 26 million years ago."
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Ancient Sumerian texts indicate that the Earth (" Tiamat ") was struck by a large planet, which moved it into its present orbit, and created the Moon and the Asteroid Belt. In his books, The Twelfth Planet and The Cosmic Code, Zecharia Sitchin outlines this "celestial battle" as described in the Babylonian text called Enuma elish. The planet "Marduk" (the Sumerian " Nibiru "), as it came into the solar system on its clockwise elliptical course, struck Tiamat, which was moving in its ordained counterclockwise orbit. One of Marduk's satellites struck Tiamat first, followed by two more of Marduk's moons. Then Marduk itself, an enormous planetary body, struck Tiamat, smashing one half of the planet into pieces, which became the Earth's Moon and the "Great Band" (Asteroid Belt). The other half of the planet, which was struck by a smaller moon of Marduk, was moved into a new orbit, along with a chunk of material which became its moon. The new planet was then called "KI," meaning "cleaved one." The Earth's original moons were dispersed, many changing the direction of their orbits.
Sitchin has also written in Divine Encounters, the planet where God the creator resides is referred to in the Bible as Olamin, the plural of Olam. The meaning of "olam" in the ancient world was a measure of a really long time, specifically related to the span of time between the periodic disappearance and reappearance of the planet Marduk/Nibiru on its vast 3,600 year elliptical orbit. (less info)