Galilean Moons

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Galilean Moons (Moons of Jupiter)

(religion, spiritualism, and occult)

Jupiter, the largest planet in the solar system, has, as one might anticipate, a large number of satellites—16 at last count (Saturn holds the current record of 17). Four of these, called the Galilean moons because they were discovered by Galileo, are large bodies—Ganymede (3,270 miles in diameter), Callisto (2,980 miles), Io (2,260 miles), and Europa (1,950 miles)—all larger than Pluto (estimated diameter, 1,457 miles). These moons orbit between 262,000 miles and 1.17 million miles away from Jupiter. Their orbital periods range from less than 2 terrestrial days (Io) to more than 16 (Callisto). All the non-Galilean moons are less than 120 miles in diameter, clearly distinguishing them from Jupiter’s Big Four.

The moons of Mars constitute the most useful starting point for the new field in astrology of planetary moon studies. The Jovian moons are also useful for this purpose, however, particularly in the ways they contrast with the Martian system. Next to Phobos and Deimos, the Galilean moons have attracted the attention of human beings more than the moons of any other celestial body (indicating that their astrological significance should be relatively easy to retrieve from the collective unconscious). To begin with, they were the first nonterrestrial moons to be discovered, and their discovery (in 1610) was an important factor in overturning the medieval European view of extraterrestrial space: In the seventeenth century they produced a sensation, comparable to the discovery of mountains on the surface of the Moon. In more recent years, as Pioneer and Voyager probes have sailed past Jupiter and taken dramatic photographs, the Big Four Jovian moons have become the focus of considerable astronomical and popular interest.

It would be difficult to dispute the idea that four celestial bodies larger than Pluto that are, even at their greatest distance away from Earth, always more than four times nearer than Pluto’s closest approach to Earth, should have some sort of astrological influence. The operative question, however, is, Does the study of Jovian satellites add anything to our understanding of Jupiter, or are these influences indistinguishably blended with Jupiter’s? An initial clue from astrological studies of Phobos and Deimos is that the Jovian moons may represent a polar opposite principle (or, perhaps, another, related principle) to some key Jupiterian principle. Another clue, taken from asteroid studies, is that the mythology associated with the name of a newly explored celestial body provides an initial guide to its astrological significance.

Zeus (the Greek equivalent of the Roman Jupiter), as anyone familiar with classical mythology knows, had an unpleasant propensity to rape everyone to whom he took a fancy, and all four of the figures after whom the Galilean moons are named were victims of the god’s lust. Ganymede was a young man whom Zeus kidnapped to become his lover and cupbearer, while Io, Europa, and Callisto were all young women raped by the king of the gods. Zeus, however, seems to have been plagued by guilt for his misdeeds, because he tried in various ways to make it up to his victims. In the case of Ganymede, Zeus gave the youth’s royal father a pair of fine mares and a golden grapevine, and Ganymede himself was immortalized as a constellation (Aquarius). Callisto was similarly transformed into a constellation (the Big Bear), Europa was given a set of unusual gifts, and Io became a queen and the ancestress of dynasties, as well as an ancestress of the hero Hercules.

Because many of the ancient gods (including the ones after whom the outer planets are named) were portrayed as rapists, focusing on the purely sexual aspect of these tales probably does illuminate the astrological/psychological principles represented by the Jovian moons. Zeus differed from many other Olympian rapists in that he showered his victims with gifts. This, of course, ties in with Jupiter’s astrological characteristic as (among other things) the principle of generosity. With some reflection, it is not difficult to see that these myths provide some less-than-pleasant insights into gift-giving: Rather than being “freely given,” as the saying goes, gifts are often given to compensate victims for abuse—or, to translate this basic principle into something closer to home, to compensate for the more subtle abuse of neglect (as when parents who feel guilty about not devoting enough time to their children shower them with gifts).

In another myth, Zeus promised to give Sinope (after whom Jupiter’s outermost satellite was named) anything in exchange for her favors, so she tricked him into granting her the gift of perpetual virginity. This shows another shadow side of generosity—giving gifts in order to receive something—that represents the polar opposite principle of generosity: greed. This principle is usually associated with Saturn, but Saturnian greed is a thrifty greed that flows out of a sense of deficiency. Jovian greed, by way of contrast, flows out of a sense of abundance and expansion, an expansiveness directed solely toward continuing to grow and accumulate. (In medical astrology, Jupiter is often associated with cancer.)

An analysis of these myths provides another perspective on generosity: Most people give gifts out of guilt or because they want something in return. Thus, the placement of Jupiter by sign and, especially, by house tells where one experiences at least one form of guilt (other forms of guilt are associated with Saturn) or where one is prone to be generous in order to get something (greed). This analysis of the Jovian moons provides astrologers with new meanings for Jupiter, meanings that were not part of traditional astrological thinking about the planet. And, as astrologers continue to explore the astrological meanings implicit in the Jovian system, more insights are likely to emerge.


Lewis, James R. Martian Astrology. Goleta, CA: Jupiter’s Ink, 1992.
McEvers, Joan, ed. Planets: The Astrological Tools. Saint Paul, MN: Llewellyn Publications, 1989.
Room, Adrian. Dictionary of Astronomical Names. London: Routledge, 1988.
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