Planet X (called Nibiru by some) had an encounter with Earth in 2003 and caused a shifting of the Earth's poles which is supposed to cause an end to our civilization. This is a very silly theory backed by bad science and old news articles that unfortunately some people believe.
Wikipedia article on Planet X (Nibiru):
http://en.wikipedia.org/wiki/Nibiru_collision
Article about the Pole Shift from the discoverer's website:
http://www.zetatalk.com/poleshft/p00.htm
Where is Planet X?
http://www.zetatalk.com/index/zeta202.htm
Article about the 2003 Earth Encounter with Planet X:
http://www.zetatalk.com/index/zeta271.htm
What signs they had in 2005:
http://www.zetatalk.com/index/zeta233.htm
About the Earth's spins slowing down:
http://www.zetatalk.com/poleshft/p127.htm
Planet X Right:
http://www.zetatalk.com/index/zeta422.htm
Spoiler:
The sun, earth, and milky way will align at the galactic equator, on December 21, 2012, the winter solstice, the shortest day of the year, and the end of the Mayan calendar. This only happens every 25,800 years! For the first time in recorded history, our entire solar system will move BELOW the milky way galaxy. These combined cosmic events, will be the end of the world as we know it. About 6 billion people of the world will perish in just a few short years if this cosmic catastrophe occurs.