solar system (and earth) passes to other side of galactic plane. Some theorize that there may be a magnetic pole shift when this occurs. I'm sure you can gather what would happen to the earth's surface if the magnetic poles shift. It's also the end of some big cycle on the Mayan calendar, and the end time according to some 4000 year old chinese fortune telling book. The only book that doesn't say it's the end is the Bible, unless week really means week and not year, in which case the antichrist will sign a peace treaty with Israel in early 2012.