Chart of the zodiac used by medieval astronomers and navigators to determine locations, 1544. (Library of Congress)

Practitioners can also have different opinions regarding the technical details invoked in the actual process of astrological divination: how many planets should be included; what significance, if any, should be attributed to the so-called astrological houses, and what method should be used in calculating these; should asteroids be considered significant; should midpoints between astrological objects be included in the chart; how should the influence of various factors be weighted in the overall interpretation of a chart; what status should be accorded such non-Western systems as Vedic astrology; and so on. The present article can do no more than provide basic information on some of the types of astrology that will be most familiar to people in Western countries: natal (birth chart) astrology, sun sign astrology, and the concept of astrological ages, followed by a very brief exploration of the role of astrology in the contemporary West.

The birth chart, in contemporary natal astrology, is a symbolic map of the heavens, as seen from the perspective of one specific human being at the time of birth. More specifically, it is generally plotted as a circle, with the place on Earth where this individual is born placed in the middle. On the circumference are the signs of the Zodiac (Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces), each of which is allotted one 30 degree segment of the circle. Due to an astronomical phenomenon known as the precession of the equinoxes, the positions of the astronomical constellations and the astrological signs bearing the same names do not correspond to each other.

The planets of the solar system are placed in the chart in the position where these appear against the backdrop of the astrological Zodiac. For astrological purposes, the list of planets includes the Sun and Moon. When plotted in this way, some planets will form angles to each other that are of particular interest to astrologers: they can overlap (astrologically speaking, form a conjunction), stand opposite to each other, or form a 90 degree angle (a square) or a 60 degree angle (a trine). Usually, astrologers will accept some degree of departure from these “ideal” angles, so that a distance of, for example, two or three degrees between two planets will still be seen as a conjunction. Finally, complex methods of calculation will divide charts into 12 sectors of unequal size, the houses.

In contemporary, psychologizing interpretations of astrology, each element of the chart will typically be associated with certain dynamics of the personality. The planets are often interpreted as symbols of the basic expressions of the human being: the conscious ego (the Sun); emotions and intuition (the Moon); aggression and assertiveness (Mars); the intellect (Mercury); responsibility, control, and inhibition (Saturn); adventurous individualism (Uranus); deep-seated impulses from the unconscious (Pluto); and so forth. The signs of the Zodiac are the various ways in which such drives are acted out, for instance, with serious commitment and service to others (Virgo), with extroversion and self-centeredness (Leo), with liveliness and a quest for a diversity of experience (Gemini), or with a forceful drive (Aries). The houses are arenas of human activities in which these expressions are acted out: the realm of material possessions (second house), communication (third house), creativity and children (fifth house), or career (tenth house). These various elements of a person’s character can to varying extents complement or stand in tension with each other, depending on the angles formed by the planets.

Many symbols have a range of standard interpretations in the astrological literature, as even this overly simplistic set of key-words should be able to convey. The task and challenge of the astrologer is to be able to formulate a narrative that—in the perspective of the person whose chart is being read—makes sense. Due to the sheer mass of information in a chart, and the many ways of interpreting any given set of symbols, these narratives can differ substantially from each other, and any example of how a particular element of a chart will be understood by the astrologer can only represent one option among many. Even within the work of one specific astrologer one finds a range of possible interpretations: the chart element “Saturn in Gemini and the third house” can, according to Jungian astrologist Liz Greene, be linked to a blockage (Saturn) in the intellect’s (Mercury) ability to grapple with the new and unexplored (Gemini), but can also manifest as an inhibition in one’s ability to speak of things that truly matter to oneself.

Astrologers will attempt to predict future trends by one of two main techniques. The method of astrological transits interprets the movements of astrologically significant objects over time, typically the angles formed between planets at the moment of divination and the moment of birth. If, say, Saturn has made a full circle around the chart and is now located at the same place as one’s natal Saturn, this can be interpreted as a sign of entering a new phase in life. The other common technique, astrological progressions, involves symbolically calculating the chart for a new time, for example, bringing the chart one day forward for each year of a person’s life. In order to assess trends for an individual at age 30, a chart would be constructed for a point in time 30 days after the birth of that person.

Compared to the many complexities of natal astrology, sun sign astrology is quite simple. This form of astrology is based on the premise that people born with the Sun in a particular zodiacal sign will undergo broadly similar events at a given point in time. Sun sign astrology is a fairly recent innovation and is generally attributed to the astrologer R. H. Naylor (1889-1952), who began writing sun sign columns in the Sunday Express in 1930. Since then, sun sign columns have become a ubiquitous part of popular culture. Precisely because of its simplicity, sun sign astrology is not only the form of astrology most widely known to the general public, but also a version of astrology that many who practice natal astrology consider crude and simplistic.

Beside such astrological practices that involve character analysis and predictions for individual people, the astrological concept perhaps most familiar to the general public is that of astrological ages, and in particular the Age of Aquarius. Due to the precession of the equinoxes mentioned above, the distance between astronomical constellations and astrological signs steadily increases, at a speed of roughly one sign each 2,160 years. Such a period of over two millennia is known as an astrological age, and many astrologers have suggested that we will either soon be leaving one such age (the Age of Pisces) or have already entered the next (the Age of Aquarius). Each age is said to be marked by certain overarching characteristics, for instance, the Age of Pisces by the dominance of Christianity (since the fish is a common symbol for that religion) and the Age of Aquarius by a more individualistic spirituality. During the spiritually adventurous 1960s it was commonly asserted that the transition into the Age of Aquarius was taking place.

Astrology occupies an ambiguous position in contemporary society. Surveys suggest that roughly a quarter or more of the population of various countries in Europe and North America profess at least a modicum of belief in astrology, and an even larger number of people read sun sign columns for their entertainment. Open support for astrology has been most noticeable in the various groups of the Western Esoteric tradition, especially Wicca. At the same time, astrology is excluded from the institutional pillars of society and is regularly characterized by skeptical voices as superstitious or pseudoscientific. When astrology does enter core social institutions, for example, in political decision making in the Reagan years or in a few university settings in the early 21st century, the response from non-astrologers has generally been very negative.

One reason for the lack of acceptance of astrology in core sectors of Western societies is the incompatibility of the astrological worldview with widespread assumptions inherent in the natural sciences and the failure of astrology to pass scientific testing. Numerous experiments have been carried out in order to determine whether astrological methods can assess personalities or predict events better than chance, and generally speaking these tests suggest that under controlled conditions astrologers fare no better than if they had proceeded via random guesswork. The disparity between the popular support for astrology and the apparent failure of astrology to live up to its promises has occasioned considerable hostile coverage by skeptics. Some astrologers have countered by attempting to support the empirical validity of their craft, for example, by citing the research of Michel Gauquelin (1928-1991), who by means of large statistical samples attempted to study the possible relations between birth times and subsequent careers. He thus claimed that there was a correlation between a time of birth with a rising or culminating Mars and a later athletic career. For the ordinary user of astrological services, however, scientific legitimacy appears to be a tangential issue, and personal experience of a good match between the astrologer’s interpretation and one’s personal self-perception is the main source of legitimacy.