Astrology is the set of beliefs that heavenly bodies influence or control human activities. The practice of astrology is the technique of charting the positional relationships between the planets, the moon, and certain stars, and interpreting such positions as effects on individuals.
In ancient times, astrology, astronomy, and religion developed in an intertwining manner. In the modern world, however, the three areas have developed separate, but related identities. Contemporary astrology is widespread among beliefs in supernatural forces. It generally ranks second, after traditional religion, among believers.
Newspapers all over the world, and in many languages publish daily astrological advice. Numerous magazines and books devoted entirely to the subject of astrology. Many practicing astrologers prepare charts and interpretations for individuals. In Asia, auspicious days for important activities are selected by astrologers. In Korea, China, and Japan, for example, they give advice on the appropriate days for weddings.
Astrology affects more than individual events. Comets and eclipses have long been seen as harbingers or war or other calamities. Among the most famous of ancient astrological writings are those of Nostradamus, published in 1555.
Western astrology can be traced directly to the theories and practices of the Chaldeans and Babylonians of the 2000's B.C. In its beginnings astrology was an attempt make practical use of astronomical observations. Based on visual observation, the ancients recognized repeating patterns of celestial movements. For agricultural purposes, the times for planting and harvesting were clearly tied to these periodic heavenly events. The prediction of rainy seasons, and the onset of winter, led to the increasing usefulness of astrology, particularly by the Indians and Chinese.
These ancients observed that the stars seemed to control much on a global scale. Then, they correctly concluded that the stars and the planets had influences on individuals, also.
The Chaldeans, Babylonians, and Egyptians, aided by the creation of mathematics, developed refined observations and calendars. Their work was the basis of all subsequent developments in the field. They linked the movements of heavenly bodies to a complex mythology and cosmology, which in a modified form, became the basis of modern Western astrological beliefs.
Astrology and astronomy remained linked from the time of the Chaldeans to Ptolemy, through the Middle Ages, and down to the period of Tycho Brahe and Johannes Kepler. These two areas continued to be developed further by the Greeks, the Arabs, and in European from the 13th century, on. Many European courts had royal astrologers to assist the monarchy.
Underlying all of these concepts is the zodiac, which assigns mythological animals to constellations of stars that appear on the ecliptic. There are twelve constellations, known as "signs", which have associations with character, temperament, physiology, aptitudes, and such. A horoscope is a diagram of the heavenly bodies showing the relative positions of the sun, moon, and planets at a particular time.
The ecliptic is a line that can be drawn in the night sky, along which travels all of the planets, the moon, and most asteroids and comets. If the ecliptic is drawn into the daytime sky, the sun adheres to this line also. In geometric terms the ecliptic generally describes the plane on which all of the planets orbit.
To make a horoscope, the astrologer uses a person's birthplace and birthdate and for utmost precision, birthtime. The positions of the planets at birth, or any subsequent time, allow the astrologer to advise the individual with respect to current conditions and future events.