In astrology, planets have a meaning different from the astronomical understanding of what a planet is. Before the age of telescopes, the night sky was thought to consist of two similar components: fixed stars, which remained motionless in relation to each other, and moving objects/"wandering stars", which moved relative to the fixed stars over the course of the year(s).
The geocentric Ptolemaic system of the universe depicted by Andreas Cellarius, 1660–1661
Luna or Diana, wearing a crescent-moon crown and driving her ox-drawn chariot (biga), on the Parabiago plate (2nd–5th centuries AD)
Full Moon
Flying Mercury (late 16th-century) by Giambologna
Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions of celestial objects. Different cultures have employed forms of astrology since at least the 2nd millennium BCE, these practices having originated in calendrical systems used to predict seasonal shifts and to interpret celestial cycles as signs of divine communications. Most, if not all, cultures have attached importance to what they observed in the sky, and some—such as the Hindus, Chinese, and the Maya—developed elaborate systems for predicting terrestrial events from celestial observations. Western astrology, one of the oldest astrological systems still in use, can trace its roots to 19th–17th century BCE Mesopotamia, from where it spread to Ancient Greece, Rome, the Islamic world, and eventually Central and Western Europe. Contemporary Western astrology is often associated with systems of horoscopes that purport to explain aspects of a person's personality and predict significant events in their lives based on the positions of celestial objects; the majority of professional astrologers rely on such systems.
Marcantonio Raimondi engraving, 15th century
The Zodiac Man, a diagram of a human body and astrological symbols with instructions explaining the importance of astrology from a medical perspective. From a 15th-century Welsh manuscript
The Roman orator Cicero objected to astrology.
1484 copy of first page of Ptolemy's Tetrabiblos, translated into Latin by Plato of Tivoli