Don't worry about it. It doesn't exist. The current recycling of the fictional Planet X is for it to hit Earth in 2012. It is supposed to be a giant planet in the outer Solar System. Please note, in this old article, that Planet X was predicted to encounter Earth in 2003. In reality, Planet X does not exist. After 2012 is past and the hype dies down, I'm sure this tired old horse will be flogged back to life for a new doomsday prediction. After all, they do need to sell their books.
"Doomsayers seem to pop up every few years. Last time, it was the alignment of the planets that somehow managed not to destroy the Earth in May 2000. Now, we have Planet X. A few people are claiming that a heretofore unknown planet in our solar system is on a very long, elliptical orbit. In May 2003, it will pass close enough to the Earth to affect it in some way, causing it to flip over (what many call a "pole shift") and spur many other huge disasters. The end result will be the deaths of many billions of people. There are a large number of web pages, chat rooms and books about Planet X and its horrible effects on the Earth. So the question is, does this planet exist, and will it come by in May 2003 and cause all this horror? No, and no."
"Let me be very clear here: Nancy Lieder, Mark Hazlewood and the rest of these Planet X people (hereafter referred to as "PXPs") are completely wrong. No rogue giant planet is about to destroy the Earth, in May 2003 or otherwise.
Zechariah Sitchin bases his entire theory of the existence of a tenth planet on ancient texts, including Sumerian and biblical writings. However, he is known to misinterpret Sumerian, sometimes grossly. His key finding is based on a seal that shows a diagram that looks like the solar system, with the Sun at the center. It appears to have eleven planets around it. Since Sumerians counted the Sun and Moon as planets, Sitchin says the extra one must be some unknown planet. He also says it has aliens on it who communicated with the ancient Sumerians.
For Planet X to be here in less then a decade, it can't be farther than a billion or so kilometers away. Even at that distance, it would be one of the brightest objects in the sky. Remember, tiny Pluto is 5 billion kilometers out, and can be easily detected using modern equipment, and Pluto is way smaller than Planet X is supposed to be. There is simply no way a big planet so close to Earth could have escaped astronomers' detection (even amateur astronomers, who even Lieder and Hazlewood must realize have no reason to lie) all these decades."