No, your zodiac sign hasn't changed

From an online article called "No, your zodiac sign hasn't changed"

Tattoo parlor owners must be salivating. An assertion in a Minneapolis Star Tribune articlethat our understanding of the zodiac is off by about a month - and thattherefore people have been identifying themselves with the wrong sign -caught fire on the internet Thursday, and many folks are in an absolutepanic on social media.

"If my zodiac symbol has been changed to a Libra, what am I supposed to do with my Scorpio tattoo?!?!," read one tweet Thursday.

Some vowed to get their tats removed. Others groaned about losingthe sign with which they’ve identified themselves for years. The zodiacand related terms - including Ophiuchus, said to be a 13th andneglected sign - were trending Twitter topics much of Thursday.

But before astrology fans scrape the ink from their arms becausethey think they're now a Virgo instead of a Libra, they should considerthis: If they adhered to the tropical zodiac - which, if they're aWesterner, they probably did – absolutely nothing has changed for them.

That's worth rephrasing: If you considered yourself a Cancer underthe tropical zodiac last week, you're still a Cancer under the samezodiac this week.

That's because the tropical zodiac – which is fixed to seasons, andwhich Western astrology adheres to – differs from the sidereal zodiac –which is fixed to constellations and is followed more in the East, andis the type of zodiac to which the Star Tribune article ultimatelyrefers.

Two zodiacs. That's nothing new.

"This story is born periodically as if someone has discovered some truth. It's not news," said Jeff Jawer, astrologer with Tarot.com.

The hubbub started with Sunday's Star Tribune article, which saidthe following: "The ancient Babylonians based zodiac signs on theconstellation the sun was 'in' on the day a person was born. During theensuing millenniums, the moon’s gravitational pull has made the Earth'wobble' around its axis, creating about a one-month bump in the stars'alignment."

"When [astrologers] say that the sun is in Pisces, it’s really notin Pisces," Parke Kunkle, a board member of the Minnesota PlanetariumSociety, told the Star Tribune.

"Indeed," the article continued, "most horoscope readers whoconsider themselves Pisces are actually Aquarians." The article alsoasserts Scorpio's window lasts only seven days, and that a 13thconstellation, Ophiuchus, used to be counted between Scorpio andSagittarius but was discarded by the Babylonians because they wanted 12signs per year.

True enough, Jawer says, the sun doesn't align with constellationsat the same time of year that it did millennia ago. But that’sirrelevant for the tropical zodiac, codified for Western astrology byPtolemy in the second century, he says.

In the tropical zodiac, the start of Aries is fixed to one equinox, and Libra the other.

"When we look at the astrology used in the Western world, theseasonally based astrology has not changed, was never oriented to theconstellations, and stands as … has been stated for two millenniums,"Jawer said.

People who put stock in astrology can ask whether they should adhereto the tropical zodiac or the sidereal zodiac. Jawer argues for thetropical.

"Astrology is geocentric. It relates life on Earth to the Earth’senvironment, and seasons are the most dramatic effect, which is why weuse the tropical zodiac," he said.