Western astrology

Western astrology is the most popular type of astrology in Western countries. It began with the work of Ptolemy in his book called Tetrabiblos, written in the 2nd century CE. Ptolemy built on older ideas from Hellenistic and Babylonian traditions.

This kind of astrology is called horoscopic, meaning it creates a special chart called a horoscope for a specific moment and place, like the exact time and location of a person's birth. People believe that stars and planets at that moment influence a person's life.

In everyday culture, many people only think about their sun sign, which is based only on their birthday. This is a simple way to look at astrology, focusing just on where the Sun was on that day.

Even though many people enjoy reading about astrology, scientists consider it a pseudoscience. Studies have not found strong proof that astrology really works. In the past, before the Enlightenment, astrology was studied seriously, but today it is mostly seen as entertainment rather than real science.

Core principles

A central idea in astrology is that everything in the universe is connected. People, the Earth, and all around us are seen as one big, living system. Changes we see in the sky reflect changes here on Earth and within ourselves. This idea is captured in the ancient Hermetic saying "as above, so below; as below, so above," showing how small things and big things are linked.

Western astrology looks at a person's birth by watching how the stars and planets line up from Earth, not from far away in space. It believes that math relationships show special energies that appear in numbers, angles, shapes, and sounds, all fitting together in a pattern. The writer Ptolemy wrote important books about these ideas, and later, Al-Kindi expanded on them in his work De Aspectibus.

The zodiac

Main article: Zodiac

The zodiac is a band of constellations that the Sun, Moon, and planets appear to move through in the sky. Astrologers have attached special meaning to these constellations, creating a system of twelve signs based on the constellations the Sun passes through during the year. Most Western astrologers use the tropical zodiac, which starts with the sign of Aries around March 21, matching the Earth's seasons. This differs from the sidereal zodiac, which is based on the actual positions of the constellations.

In modern Western astrology, these twelve signs are thought to represent different personality types. They are grouped into four elements — fire, earth, air, and water — and three qualities: Cardinal, fixed, and mutable. A person's "sun sign" or "star sign" is often used in newspapers for general daily guidance, though astrologers note these are very broad and not very accurate on their own.

Main article: Sun sign astrology

The planets

Main article: Planets in astrology

In Western astrology, planets represent basic drives or impulses in the human mind. These planets include the Sun, Moon, and even Pluto, which is not considered a planet in science but is treated like one in astrology. Each planet is linked to one or two animal signs of the zodiac, influencing different parts of life and personality.

The classical planets are the seven heavenly bodies known to ancient people. These include the Sun and Moon, called "the lights," and five other objects that move against the stars. The inner planets — Mercury, Venus, and Mars — are called "personal planets" because they affect our immediate feelings and actions. The lights represent the core of who we are and our sensitivity.

Modern modifications to the Ptolemaic system

Western astrology has changed over time to include new planets discovered in modern times. Astrologers give these planets special meanings based on their positions.

There are two main ways astrologers think about the starting point of the zodiac. Sidereal astrology uses a fixed point based on the stars, while tropical astrology, used by most Western astrologers, uses the Sun's position during the spring equinox each year. Because the Earth wobbles on its axis, these two systems slowly move out of alignment with each other over thousands of years. This shift is called the Precession of the equinoxes.

Astrologers also pay attention to special points called the moon's nodes, where the Moon's path crosses the Sun's path in the sky. These points are thought to mark important areas worth considering.

The horoscope

Main article: Horoscope

Western astrology focuses on creating a horoscope, which is like a map of the stars and planets at a special moment — often the moment someone is born. This map is believed to show influences that will affect a person's life. The most common type is the natal chart, made for the exact time and place of a person's birth. But horoscopes can also be made for other important moments, like starting a business or a country.

Astrologers look at several key things in a horoscope. They study where planets are in the zodiac signs, how planets are placed in different areas of the chart called houses, and the angles between planets. These angles, called aspects, show how planets work together or against each other. By understanding these pieces, astrologers try to give insights into a person’s character, life events, and future possibilities.

Astrology and science

Main article: Astrology and science

Most professional astrologers use tests to guess personality traits and predict the future. However, many believe in astrology even though there is no real scientific proof to support it. Astrology is seen as a pseudoscience because it has not shown it works in careful tests and lacks a real explanation for how stars and planets could influence life on Earth.

One famous study led by Shawn Carlson found that natal astrology could not predict better than random guesses. This shows that astrology has not been proven to work in ways that can be tested.