The moon is earth’s companion satellite, though some astrologers believe that it approaches being a planet in its own right. The moon is large enough for its gravity to affect the Earth, stabilizing its orbit and producing the regular ebb and flow of the tides. The moon is familiar to us for its different phases, waxing and waning in appearance in an unchanging cycle. The moon orbits the earth in 28 days, spending a fleeting 2.33 days in each of the signs of the zodiac.
The moon is the ruling planet of (the astrological sign) Cancer. In Roman mythology, the moon was represented by Diana, the hunter goddess. In Western astrology the moon is said to represent the feeling nature of the individual. It is used to characterize the inner child within us, as well as the past and how we have been as individuals rather than how we are now. In the horoscope, the aspects the moon makes with other planets and the transits the slower moving planets make to the moon are all said to have a strong impact on how our lives unfold.
The moon is associated with a person’s emotional make-up, unconscious habits, rhythms, memories and moods. It is also associated with the mother, maternal instincts or the urge to nurture, the home, and the past. The first-century poet Manilius described the Moon (or Luna) as melancholic. In medicine the moon is associated with the digestive system, stomach, breasts, the ovaries and menstruation, and the pancreas. The moon is the ruler of the 4th house.
The moon is also said to represent receptivity, vulnerability, etc. but this should not suggest that its power is considered less than the sun’s. From an astrological perspective (in which we assume, for the sake of argument, that the earth is fixed and everything else moves) the sun and moon are the same size. From an astrological perspective, they are equals; a solar eclipse reminds us of this so that we do not doubt the power of the moon, which is hidden and mysterious but no less influential.
In Aristotle’s description of the universe, the moon marked the boundary between the spheres of the mutable elements (earth, water, air, and fire), and the imperishable stars of aether. This separation was held to be part of physics for many centuries after.
By the Middle Ages, before the invention of the telescope, more and more people began to recognize the moon as a sphere, though they believed that it was “perfectly smooth”. In 1609, Galileo Galilei drew one of the first telescopic drawings of the moon in his book Sidereus Nuncius and noted that it was not smooth but had mountains and craters. Later in the 17th century, Giovanni Battista Riccioli and Francesco Maria Grimaldi drew a map of the moon and gave many craters the names they still have today.
On an interesting side note, Russia and the U.S. are party to the Outer Space Treaty, which places the Moon under the same jurisdiction as international waters (res communis). This treaty also restricts use of the Moon to peaceful purposes, explicitly banning weapons of mass destruction (including nuclear weapons) and military installations of any kind.
A second treaty, the Moon Treaty, was proposed to restrict the exploitation of the Moon’s resources by any single nation, but it has not been signed by any of the space-faring nations. Several individuals have made claims to the moon in whole or in part, though none of these claims are generally considered credible.
References: Wikipedia.com; C.S. Lewis, The Discarded Image, p 108, Cambridge University Press, 1964, Cambridge ISBN 0-521047735-2; Van Helden, Al (1995). The Moon. Galileo Project. Retrieved on 2007-01-12