Planets in astrology have a different meaning than the traditional understanding of the planets. Before the advent of telescopes, the night sky was believed to consist of two very similar components: fixed stars, which remained motionless in the sky, and the "wandering stars" which moved relative to the fixed stars over the course of the time.
To the Greeks and the other earlier astronomers, this group comprised the five planets visible to the naked eye, and excluded the Earth. Although strictly the term "planet" applied only to those five objects, the term was later broadened, particularly in the Middle Ages, to include the Sun and the Moon (sometimes referred to as ‘Lights’, making a total of seven planets. Astrologers have retained this definition even at today’s date.
To ancient astrologers, the planets, however, represented the will of the gods and their direct influence upon human affairs. To modern astrologers, the planets represent basic drives or urges in the unconscious or energy flow regulators representing dimensions of experience. They express themselves with different qualities in the twelve signs of the zodiac and in the twelve houses. The planets are also related to each other in the form of aspects.
Modern astrologers differ on the source of the planets' influence. Some believe that the planets exert it directly through gravitation or another, unknown influence. Others hold that the planets have no direct influence in themselves, but are mirrors of basic organizing principles in the universe. In other words, the basic patterns of the universe repeat themselves everywhere, in fractal-like fashion, and "as above so below". Therefore, the patterns that the planets make in the sky reflect the ebb and flow of basic human impulses. The planets are also associated, especially in the Chinese tradition, with the basic forces of nature.
Listed below are the specific meanings and domains associated with the astrological planets since ancient times, with the main focus on the Western astrological tradition. The planets in Hindu astrology are known as the Navagraha or "nine realms". In Chinese astrology, the planets are associated with the life forces of yin and yang and the five elements, which play an important role in the Chinese form of geomancy known as Feng Shui.
The Sun represents the self, one's way of being in the world. It can represent, on different levels, both the ego and the higher Self or soul purpose. It rules Leo and is exalted in Aries.
The Sun is the most important 'planet' in the chart and symbolizes one's will and sense of vitality. When the Sun is afflicted (poorly placed or poorly aspected) it could indicate problems with the father, or male role model.
The Moon represents the personal self, the feelings and the unconscious. It is a reflection of the true self, represented by the Sun. The Moon also stands for security and instinctual or habitual patterns, as well as the ability to relate to others, and to be nurturing to others. The Moon rules Cancer and is exalted in Taurus. It is often contrasted with the Sun as the female receptive principle versus the masculine or positive principle. The Moon represents the feminine and nurturing part of oneself. In a male chart, the Moon represents the feminine within, or the anima and also indicates the type of partner you will attract. The Moon also represents an attunement from the past, which operates at an instinctive or habitual level in your present life.
Tiny Mercury is the innermost and smallest planet in the solar system and can only be seen at morning and evening twilight. Because of this, the ancient Greek astronomers believed the planet to be two separate parts - one visible only in the morning which they called Apollo, and one visible in the evening, which they called Hermes. Later, the Romans named the planet after the God Mercury, a messenger and God of trade, profit and commerce. The astrological symbol for the planet Mercury is taken from this God's wand or caduceus, which is typically depicted as a short herald's staff entwined by two serpentine creatures, and which in later antiquity became the astrological symbol for commerce. A variation of this caduceus has come to symbolize medicine in modern times.
Lovely Venus is the second-closest planet to the Sun, and is the brightest natural object in the night sky, except for the Moon. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it is often called the Morning Star or the Evening Star. She is also sometimes called Earth's "sister planet", for the two are similar in size, gravity, and bulk composition. Her dense atmosphere creates a greenhouse affect, consequently raising temperatures hot enough to melt lead! At one time Venus had voluptuous amounts of water on her surface, but that has long since boiled away, and has been replaced with steamy hot lava flows and gently rolling plains. Venus is the only planet in the Solar System named after a female figure, since Ceres and Eris are dwarf planets.
Mars is the fourth planet from the Sun, and is named after the Roman God of War. It is also referred to as the Red Planet because of its reddish appearance as seen from Earth. It is the site of Olympus Mons, the highest known mountain in the solar system, and of Valles Marineris, the largest canyon.
In astrology, Mars is the planet of outward activity and animal passion including our sexual drive, aggression, and anger. Mars rules Aries and is exalted in Capricorn. This fiery planet is masculine in action, versus the softer more receptive and romantic Venus. When strong in the chart it can indicate a volatile temper, and also great courage. Its position indicates how your personality will assert itself, and what modes of activity will stimulate your physical energies, or your anger. By house, Mars represents where you will assert yourself, and where you will take action in the most positive sense.
Turbulent Jupiter is a gas giant - meaning that it is not composed of rock or other solid matter. It is the third brightest object in the night sky after the Moon and sparkling Venus, and is the largest planet within the solar system. Jupiter's outer atmosphere is home to a massive storm called the "Great Red Spot" that has existed since at least the seventeenth century! Jupiter was named after the Roman God, and served as the patron deity of the Roman State. In other words, Jupiter ruled over laws and social order much like Zeus for the Greek State.
The beautiful and severely wind beaten Saturn is the sixth planet from the Sun and the seventh and last planet of ancient astrology. The celebrated day Saturday gets its name from the planet, and it is known for it's prominent and stunning ring system, consisting mostly of ice particles, rocky debris, and dust. Although the ancient order had no telescopes to see Saturn's famous rings, Saturn still became known as the planet of boundaries, which is symbolized by the ring. Saturn is the second largest planet in the Solar System, after Jupiter. It was named after the Roman god Saturnus, equated to the Greek Kronos, the Titan father of Jupiter (Zeus). Saturn's astrological symbol represents this god's sickle, as well as the elevation of the cross of Matter above the semi-circle and openness of Spirit.
Uranus, the seventh planet from the sun, is known as one of the Ice Giants, along with Jupiter, Saturn and Neptune. This is because its atmosphere contains a high proportion of ices such as water, ammonia, and methane, and partly because it is the coldest planetary atmosphere in the Solar System, with a minimum temperature of around negative 371 degrees Fahrenheit. It is named after the ancient Greek deity of the sky, the father of Kronos (Saturn) and grandfather of Zues (Jupiter). However, it has been argued that Uranus finds more mythological relevance in Prometheus.
Neptune is the eighth planet from the Sun in the Solar System, and is seventeen times the mass of Earth. While Neptune boasts the strongest winds of any other planet in the solar system, it also has an intense bright blue appearance that is attributed to trace amounts of methane in its atmosphere. The planet is named after the Greek God of the Sea Poseidon, and its astrological symbol is a stylized version of Poseidon's mighty three pronged trident.
Pluto has recently been termed a dwarf planet by a convening of the International Astronomical Union in Prague. Of course, this does not diminish its importance for astrologers. Since there is a well-established body of research on the very distinctive effects of Pluto in natal charts, by transit, and in combination with other transiting outer planets, we will go on just as always. It does mean that newly designated dwarf planets such as Eris and Ceres will be given a seat at the table, and are likely to become better understood as astrological symbols before much more time has passed.