There's a new zodiac sign, folks. It's Ophiuchus, the Serpent Bearer (or snake charmer, depending on whom you ask).
You see, when the original zodiac was calculated by the International Astrological Union in ages past, it was mistaken. For one thing, it's gotten a bit off since the earth has wobbled on its axis a skosh. This sort of thing happens over a period of thousands of years, and the good guys at Hayden Planetarium assure us that it's nothing to worry about. But in addition to the original charts-by-date being mistaken, the Babylonians (who were obviously Griffindors) refused to include Ophiuchus (obviously a Slytherin). You see, it doesn't make for a nice mathematically creamy number to have 13 signs. So they threw Ophiuchus out like yesterday's garbage and blazed forward without him, making such brilliant strides in the empirical science that is astrology.
In fact this news is nothing new either! Astronomers have actually known about this for decades, perhaps longer! But it's on the intertubes now, and the news outlets having such a slow news day (what with a funeral for a victim of a shooting that was attended by the President, another victim of the same shooting coming out of a coma, horrendous flooding in Australia and Brazil... there's just nothing to report!) caught wind of this and decided to really mess with John Q. Public's head by announcing the shocking, whirlwind report that astrology just might be arbitrary.
My personal favorite reaction comes from the comments at this report by the Christian Science Monitor.