Perhaps you identify the term "zodiac" with astrology, but it also has a role in astronomy. The yearly passage of the sun across our sky defines it. The Zodiac, or the 12 signs of the zodiac stated in a horoscope, is intimately related to how the Earth travels through the skies. It is here that we find the planets orbiting the Sun in orderly fashion. Without this framework, astronomers would have a difficult time predicting solar and planetary events.
The zodiac has many definitions depending on who you ask. Some say it is a map of the stars located within 30 degrees of the celestial equator. This would include all the constellations visible from Earth, along with parts of the Milky Way Galaxy. Others say it is a collection of symbols representing the different positions of the Sun during its annual journey around Earth. Still others claim it is a list of names given to each portion of the Moon's orbit. There are even those who say it is a list of names given to each constellation. The only thing common among all definitions is that they are all based on the position of the Sun in the sky.
In addition to being important for astronomers, the zodiac has great cultural significance. It has been used by many civilizations throughout history as a guide for planning their lives. The Chinese identified each month with a zodiac sign to organize their annual calendar. The Greeks and Romans did the same thing using a different system.
The signs are drawn from the constellations that outline the journey the sun seems to take over the course of a year.
There are actually two zodiacs used in common practice: the modern zodiac and the ancient zodiac. The modern zodiac was created in the 15th century by European astronomers who were trying to establish a system of naming the planets that would be consistent between cultures and centuries. It is this zodiac that is used in western astrology.
The ancients zodiac was different in that it was based on the positions of the stars rather than the planets. This older zodiac dates back as far as 1000 B.C. and was originally used by Greek and Roman astronomers. It is this zodiac that is used in eastern astrology.
Both systems work on the same basic idea: the position of the Sun at birth determines what sign you are born under. However, they differ in how they define each sign. For example, people who are born under the sign Aries are said to have a hard time making decisions even though there is no real way to tell until after they are born.
The Zodiac is a belt across the skies that extends 9 degrees on either side of the ecliptic, the plane of Earth's orbit and the Sun's apparent yearly course. The orbits of the Moon and the major planets are also totally contained inside the zodiac. It is named after the constellation it covers: the Sun passes through them in order from north to south.
The zodiac has been important for navigation and astrology since ancient times. It was originally defined by the constellations through which the Sun passed each year. Today, it is generally accepted that the zodiac consists of 12 constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, and Pisces.
In mythology and folklore, the zodiac has been associated with different characters, such as the twelve labors of Hercules or the seven sins. Astrologically, the zodiac is significant because it forms the boundaries of the signs, which represent different parts of the human body or mind. These signs have been used for thousands of years as a tool for understanding how humans think and feel.
The stars of the zodiac can be divided into two groups: those that lie closer to us (the Milky Way Galaxy) and those that lie farther away (galaxies beyond ours).
According to the Oxford English Dictionary, the word "zodiac" derives from Greek, from a phrase for "sculpted animal figure," and the sequence in which the signs are commonly enumerated comes from that period as well. However, the signs themselves were originally defined as parts of the sky, so they are cosmic rather than terrestrial entities.
The astrological zodiac is a circle divided into 12 equal parts called constellations or signes. Each constellation represents a different zodiacal sign. The signs were originally defined by astronomers as parts of the night sky based on their position relative to Earth's orbit around the Sun; however, today they are often interpreted as representations of different astrological elements: fire for Aries, earth for Taurus, air for Gemini, water for Cancer, etc.
The ancient Greeks adopted the zodiac and used it to divide up the year. They assigned each month of the year to one of the twelve signs of the zodiac, starting with Aries (the first sign) and ending with Pisces (the twelfth sign). So, for example, when Plato wrote his dialogue The Dialogues of Plato he grouped all of the conversations between various characters around the issue of love. He did this by referring to specific signs of the zodiac such as Aries, Taurus, Gemini, etc.
As a result, everyone has a matching zodiacal sign based on the time of year in which they were born. Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces are the 12 signs. People think that various sun signs of the zodiac represent distinct traits and abilities. In fact, it's more accurate to say that each sign is simply a different point on the ecliptic (the path that Earth travels around the Sun) relative to the constellation where it sits. For example, someone who is born in March has their sun in Pisces (fish). This doesn't mean that they are all like fish or even particularly sensitive or emotional; it's just a general indication of where they sit on the axis of personality that we call "nature vs. nurture".
The ancient Greeks developed a system of classifying people based on the positions of the Sun at their time of birth. They called these classes decans, meaning "tenants". Today, these classifications are used by astrologers to help identify traits for individuals. There are two main types of sun signs: solar and lunar.
Solars are based on the position of the Sun at birth, while lunaons are based on when it rises next after birth. If we take a look at the solar zodiac, we can see that it contains twelve symbols or constellations that represent different traits and behaviors associated with the Sun as it moves across the sky.
Zodiacal constellations are those that are located along the plane of the ecliptic. The ecliptic, or visible path of the Sun, is defined by the Sun's round journey through the sky as viewed from Earth. In other words, throughout the course of a year, the Sun seems to traverse through these constellations. They were originally identified by astronomers who were trying to understand how planets moved around the Sun. Today they are used as a basis for predicting meteor showers and astronomical events generally.
The zodiac consists of 12 constellations listed below, with the corresponding celestial objects they contain:
Aquarius (the Water-Pig): Jan 20 - Feb 18: Crab (the Water-Pig's face)
Aries (the Ram): Mar 21 - Apr 19: Ram (the Ram's head); also contains part of Taurus (the Bull) on opposite side of the Milky Way Galaxy
Taurus (the Bull): May 20 - Jun 21: Bull (the Bull's head); also contains part of Aries (the Ram) on opposite side of the Milky Way Galaxy
Gemini (the Twins): Jul 22 - Aug 23: Twins (two stars in the constellation Gemini); also contains part of Cancer (the Crab) on opposite side of the Milky Way Galaxy