However, the Earth's axis has shifted since the Babylonian's time, and the sun is no longer in the same positions.
The Minnesota Planetarium Society released a new astrological chart on Thursday which has the internet in an uproar. Most signs have been shifted one to the right, and a thirteenth sign (Ophiuchus) has been tacked on at the end.
(Disclosure: as my birthday is July 20, I am one of the few people whose sign did not change.)
More peculiar even than this big date shuffle is the introduction of a thirteenth astrological sign, Ophiuchus, the serpent-carrier. (Also called Serpentarius, which sounds much more snappy.) Ophiuchus rules those who were born November 29th through December 17.
Although Ophiuchus is apparently unknown in the West (judging by the number of people on Twitter who have tweeted some version of "WTF?" since Thursday), it has been somewhat popular in Japan since the mid 1990s. Ophiuchus has been used along the edges of astrology since at least the 4th century, often as an "extra-zodiacal indicator."
Ophiuchus was popularized in Japan after a book by Walter Berg about "13-sign astrology" was released in 1995. Berg's book was a bestseller in Japan, and became infused into pop culture. If you are wondering about the traits of someone born under Ophiuchus they are not very flattering and incude hypochondria, paranoia, and prudery.
Berg's 13-sign astrology was designed to correct for exactly the astronomical conditions which have caused this big dust-up in the news. The 13-zodiac system uses the actual constellations, and the position of the sun in each. Because of the shifting which takes place over time, the length of each zodiac sign varies.
The Western 12-sign astrological community has been trying to stem the tide of panic, with little success. It turns out that astrologers have known about this for several thousand years. (How could they not?) They maintain that the Babylonians' original predictions remain correct.
Most laypersons believe that the astrological signs directly influence a person's life and personality. But astrologers believe that they are simply a useful indicator. Confusing the stars' alignments with the force behind personality traits is like confusing a road sign that says "Seattle 120 miles '" with the city of Seattle. The road sign merely indicates the conditions, it doesn't create or predict them.
So what does make the zodiac work? Any reputable astrologer will tell you that the sun sign predictions in the daily newspaper are junk. Even the broader by-sign personality descriptions are borderline. According to professional astrologers, it is the position of the planets which determines your personality and fate. This of course varies day by day - minute by minute - which is why a true astrological chart reading requires the date and time of your birth.
Photo credit: Wikimedia Commons