Zodiac: 5 Things You Should Know

Question: Zodiac signs are tied to Greek myths, yet the system is much older. How did the 12 signs first reach the Greeks?

Answer: The zodiac began in Babylon, in modern-day Iraq, over 2,500 years ago, where astronomers split the sun’s yearly path into 12 equal parts. The Greeks later adopted it and gave the signs their familiar names and myths.

Question: Each zodiac sign covers about one month of the year. How does a person’s birth date connect to one of the 12 constellations?

Answer: As Earth orbits the sun, the sun seems to drift through a band of 12 constellations over the year. Your sign is the constellation that sat behind the sun on your birthday.

Question: Zodiac dates were set 2,000 years ago. Why is the sun now usually in a different constellation on your birthday than your sign?

Answer: Earth wobbles on its axis like a slow spinning top, finishing one wobble about every 26,000 years. Over 2,000 years, this has shifted the sky so most people’s sun is now in the sign before theirs.

Question: The sun’s yearly path crosses 13 constellations, not 12. Why does Ophiuchus, the snake-holder, have no zodiac sign?

Answer: The sun actually spends about two weeks in Ophiuchus each year, between Scorpio and Sagittarius. Ancient astronomers left it out to keep a tidy match of 12 signs for 12 months.

Question: China has a 12-animal zodiac with signs like the rat and dragon. How is a Chinese sign chosen differently from a Western one?

Answer: The Chinese zodiac cycles through 12 animals year by year, so everyone born in the same year shares a sign. Western signs change about every month as the sun moves through the constellations.