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Science and the Lunation Cycle Date Published: 11/14/2002 by Michael Erlewine
Bio: Michael Erlewine

Author Michael Erlewine Besides being the author/astrologer behind our top-selling Astro*Talk, TimeLine, and Friends and Lovers report programs, Michael is the man who founded Matrix back in the late '70s. Michael and his brother Stephen Erlewine (Stephen is still head of all astrological programming for Matrix) built Matrix into the leading producer of astrology software.

For many years Michael lived in Ann Arbor, Michigan, where he was much in demand as a counseling astrologer specializing in relationship and vocational advice. He also taught astrology at local schools and colleges, working with groups of as many as 1,200 people.

Michael is also known for his entrepreneurial drive which, in addition to Matrix, led him to create the All Music Guide - the largest music database in the world - and the All Movie Guide, as well as several award-winning websites, including

Michael also founded the Heart Center Library, the largest astrological library in North America that is open to the public. He remains curator of the works contained in this library, tapping this resource for one of his pet projects - a complete astrological encyclopedia.

Today Michael lives in the northern Michigan community of Big Rapids with his wife of 33 years and his family. He still does occasional private astrological counseling as people from around the world continue to seek his advice.

Those interested in a personal reading by Michael may contact him at:



Abstract: Modern scientific research into lunar activity as it affects the earth is presented in brief form. The similarity is pointed out between the observance of the 10th and 25th lunar days in Eastern astrology and recent theories of a lunar modulation of solar corpuscular radiation around these same times. Scientific research into the lunation cycle over the last 15-20 years is fascinating from an astrologer's perspective. It was not very many years ago that science gave little or no credence to the possibility of a lunar effect on life here on earth. Today it is no longer a question of "is there an effect?" but rather one of "let me count the ways." In fact, the research at this point is so extensive that in this brief article we can only mention some of the high points in the existing literature.

It should go without saying, but I will repeat it here, that science still has little or nothing to say about psychological or personal events connected with lunar activity. Instead, it has discussed how the moon relates to such things as rainfall, weather, and atmosphere. More important to astrologers, and a step closer to the psychological, is the growing evidence for a hard connection between lunar activity and geomagnetic activity. It is this connection that we will detail here.

Geomagnetic activity coming from beyond the earth's aura or atmosphere has been linked to all kinds of mundane activities ranging from radio reception to the aurora borealis type displays and so on. The picture that emerges from modern research is one where each body (the earth, the, sun, and perhaps even each of us) is surrounded by some sort of magnetic field. We radiate, and this radiation surrounds us and even keeps some things out.

The earth's aura (or magnetosphere as it is called) keeps at bay enormous amounts of radiation coming from the sun and from the galaxy in which our solar system is a part. Very energetic particles can penetrate our magnetosphere and find their way through the atmosphere to the surface of the earth itself. For the most part, these particles funnel in from the north and south polar caps via field lines of high geomagnetic declination. During times of increased solar activity such as solar flares, or during the peak of the sunspot cycle (like this year), very much more solar radiation reaches the earth than at other times. The weaker cosmic radiation must wait for the years of sunspot minimum to reach their maximum penetration. Please examine the diagrams of the magnetosphere shown below as we examine some of the scientific evidence that relates to the lunation cycle — lunar power.

Auroras — Although we have long studied oceanic tides, we know now that there are atmospheric tides as well that move in response to the position of the Moon. For example, auroras are caused by the excitation of atmospheric molecules by energetic charged particles penetrating the atmosphere along geomagnetic field lines. Although the mechanism of this phenomenon is still being examined, it is generally understood that auroras are associated with the arrival of solar corpuscular radiation in the magnetosphere, 1 to 3 days after a solar flare. These particles (depending on their intrinsic energy and the current density of the atmosphere) penetrate the atmosphere.

It has now been shown that these auroral peaks and valleys are modulated by the position of the Moon. This lunar auroral tidal effect in the upper atmosphere can be correlated with flood and ebb tides on earth, thus linking its rise and fall to the position of the Moon in its monthly cycle.

Rainfall — It has been well documented that rainfall is correlated with the Moon's position in its monthly cycle. According to many studies, rainfall maximizes midway through the 1st and 3rd quarters of the lunar synodic month. In other words, about a half week after new and full moon rainfall reaches a peak. Correspondingly, a low point in rainfall occurs during the 2nd and 4th quarters with the lowest point of all occurring some three days before new or full moon.

In addition, it was found that increased rainfall at these two peak times in the month was greater at solar minimum than at solar maximum. The lunar cycle accounts for 65% of the variance during years of solar minimum, but only 14% during the year surrounding solar maximum. It has been suggested that cosmic radiation may be a factor, since this form of radiation penetrates more deeply into the solar system during years of low solar activity. During the years of high solar activity, a more powerful solar wind helps to keep out cosmic radiation.

Cosmic radiation consists of energetic particles entering our solar system from beyond its aura, or magnetosphere.

Thunderstorms and Cosmic Radiation. It has been shown that the maximum in thunderstorms coincides with the maximum in galactic cosmic radiation and vice versa, that minimum thunderstorm activity coincides with the minimum in galactic cosmic ray radiation. There have been many studies on the relationship of cosmic radiation to lunar activity. Cosmic radiation consists of energetic particles entering our solar system from beyond its aura, or magnetosphere. As mentioned, there is an inverse relationship between cosmic radiation and solar activity. In other words, the increased solar wind at sunspot maximum keeps cosmic radiation out of the solar system and away from the earth. During the years of sunspot minimum, cosmic radiation is strong enough to penetrate the solar aura and reach the earth's atmosphere.

Thunderstorms and the Moon — It has been shown that the maximum in thunderstorms coincides with maximum geomagnetic activity. In addition, it has been shown that thunderstorm activity is modulated by lunar position. The greatest number of thunderstorms occur after either new or full moon. Thunderstorm frequency reaches a maximum two days after full moon and remains high for most of the third quarter.

The Moon and Geomagnetic Activity — The Kp-geomagnetic index varies with the lunar phases. When the Moon is less than 3 1/2 degrees from the plane of the ecliptic, geomagnetic activity reaches a minimum during the 2nd lunar quarter and a maximum during 3rd lunar quarter. Lunar modulation while near the ecliptic suggests that the Moon is influencing the solar corpuscular flux which, guided by the solar magnetic field, approaches the earth generally from close to the plane of the ecliptic. Some of these particles become trapped in the magnetosphere.

There is a thin, neutral-sheet region close to the ecliptic plane in the tail of the earth's magnetosphere that the Moon might be modulating when it is traveling near the plane of the ecliptic. The high density of field lines near the ecliptic would make this region particularly sensitive to a magnetic perturbation, which could modulate the flux of particles reaching our atmosphere. In short, there is evidence that the moon has a magnetohydrodynamic wake with an enhanced magnetic field, which, when in the magnetospheric tail, causes magnetic disturbances on the earth.

Polar Cap Absorption (PCA) — PCA happens when solar protons from solar flares enter the earth's upper atmosphere in high geomagnetic latitudes, often causing radio blackouts and increased auroral activity. These periods of severe ionospheric disturbance are often marked by Forbush decreases, when the counting rate of background galactic cosmic radiation has a sudden anomalous decrease which might take hours to days to recover to normal levels.

In effect, it is as if there were a magnetic screening of galactic cosmic radiation by the enhanced solar plasma. It has been noted, but unexplained, that PCA events and Forbush decreases seem to be ordered with the lunar synodic period (29.5 days). When this research was begun, it was expected that a 27.3-day period would be found, indicating a link with solar rotation. It was a surprise to scientists when, instead, results fingered the lunar synodic period (29.5 days). Therefore, it is possible that the moon somehow controls solar corpuscular radiation streaming toward the earth. The mechanism is still undetermined at this time.

Solar Sectors — Solar sectors and the geometry of the solar magnetic field represent important areas for research. The solar wind is a plasma of charged particles endlessly being ejected from the surface of the sun. These particles tend to concentrate in the plane of the ecliptic. All of the planets are within the aura or atmosphere of the sun, the solar wind. Each charged particle moves away from the sun in a straight line; however, since the sun itself is rotating, these particle streams get bent into a spiral of the type made famous by Archimedes. In addition, this plasma contains a frozen-in magnetic region constituting the sun's magnetic field that conforms to this spiral. This is the interplanetary magnetic field.

Because of this spiral effect, at the distance of the earth the magnetic field is oriented about 45 degrees west of the earth-sun line, on the morning side of the earth. Both the slow (4 days) and fast (10 minutes to several hours), charged, solar particles approach the earth guided by the solar magnetic field. They come in from the western side of the sun (morning side of earth) at about a 45-degree angle to the earth, although this angle fluctuates from moment to moment, based on the changes in the solar plasma. The fact is that each of us are exposed to this general direction around 9 AM each morning. We are most shielded from this direction around 9 P.M. each night.

The great rotating disk of the solar magnetic field itself is divided into four primary sectors, each with an alternating polarity. The magnetic field direction is either positive (away from the sun) or negative (toward the sun). These sectors are tied into definite regions on the surface of the sun, which are of corresponding magnetic signs. It has been suggested that this may be thought of as a rigid disk in the plane of the ecliptic with four quadrants connected to the sun and rotating with it in its 27-day rotation cycle — the co-rotating sector structure.

It has been found that geomagnetic and cosmic ray activity, as well as the velocity and number density of the solar wind flux, vary as a function of position within the solar sectors; thus there is a weekly fluctuation in the Kp-geomagnetic index. Studies show a maximum in thunderstorm activity when the earth passes from a positive sector into a negative sector. These four great sectors like a great pinwheel rotate past the earth exposing our planet to alternating positive and negative solar phases.

A study of the lunar position in relation to the Kp-geomagnetic index, PCA, and Forbush decreases shows that PCA and Forbush decreases reach a minimum during the middle of the 4th lunar quarter when the moon is near the 45° axis and thus between the earth and the spot where the charged particles arrive from the sun. A maximum for these values is reached when the moon is in the 2nd quarter, unable to block the particle advance. It has been shown that the moon has an electrical charge of at least 100 V/m, which means that the moon has a positive electrical charge that can deflect solar protons.

There is also a minimum in the Kp-geomagnetic index during 2nd quarters when PCA and Forbush decreases are at a maximum. It has been suggested that at 2nd quarter the moon may least disturb the geomagnetic field, which is, at that time, most active. There is a sharp rise in the Kp index just prior to full moon and continuing into third quarter. It has been suggested that this might be due to the magnetohydrodynamic wake of the moon interacting with the tail of the magnetosphere or modulating the flow of solar particles to the tail.

It is interesting to note that around that the 2nd quarter, 10th/11th day are the maximum for PCP activity. This is when the father-line deities are observed in Eastern astrology. The 25th/26th days are when the Moon somehow block or inhibits the solar magnetic field. This is when the mother-line deities are celebrated in that tradition. Thus the time of greatest activity (male) has some scientific backup, and the same for least activity and greatest calm (female).

Tidal and Electrical Influence

The western portion of the sun is strongly magnetically linked to the earth, while the eastern portion of the sun is not. This is due to the fact that solar corpuscular radiation approaches the earth from the west, guided by the solar magnetic field. As pointed out, these particles come in from the Western side of the sun at about a 45° angle to the morning side of earth. Statistical studies show that solar flares occurring on the eastern portion of the sun are much less frequently associated with geomagnetic storms than those occurring near the central or western portion.

Flares occur during periods of solar activity, which typically last a few days. These regions of activity (near sunspots) travel from east to west across the face of the sun, with a sunspot taking about seven days to travel from the central meridian to the western limb. Thus active solar regions (generating particles capale of reaching the earth) move into and through the western section of the sun, which is magnetically linked to the earth. During this period, recurrent particle streams from an active sunspot region can reach the earth. Some periods when solar protons have bombarded the upper atmosphere have lasted over ten days.

This has been a very brief description of some of the geophysical research that has been performed in the last 20 years and that might be of interest to astrologers. It seems that all bodies have a field or aura around them. The earth and the sun radiate, and that radiation is swept along behind whatever trajectory the object travels. It is fascinating to see scientific evidence emerging that seems to conform with the astrological tradition.

As pointed out in the previous article on the lunation cycle, the 10th and 25th lunar days have been found (for ages) to be significant periods within the month, where some kind of change or transition takes place. It is interesting to note that, these points are more or less in line with the 45° vector along which solar corpuscular radiation reaches the earth.

The Moon in its monthly cycle appears to (somehow) modulate this stream of radiation when it reaches the area surrounding a solunar phase angle of some 315°. At this point the moon (perhaps due to its magnetic field) effectively blocks and cuts off some of the radiation stemming from the sun. At the opposite point in its orbit (around 135°), the Moon reaches a point of least blockage, where the most solar radiation can penetrate and reach the earth.

It is this point in the lunar 2nd quarter, during which the greatest amount of radiation is available to the earth, that the Eastern astrologers have set aside as a time for the masculine (active) element. The fourth quarter, where the Moon effectively blocks the solar radiation, is the point when the feminine energies are most observed.

It is interesting that, on the surface at any rate, ancient tradition and modern science appear to have some general agreement.


B. Bell and R.J. Defouw, Dependence of the lunar modulation of geomagnetic activity on the celestial latitude of the moon, J. Geophys. Res. 71 (1966), 951-957.

D. A. Bradley, M.A. Woodbury and G. W. Brier, Lunar synodical period and widespread precipitation, Science 137 (1962), 748-749.

G.W. Brier and D.A. Bradley, Lunar synodical period and precipitation in the United States, J. Atmos. Sci. 21 (1964), 386-395.

H.W. Dodson and E.R. Hedeman, 1964: An unexpected effect in solar cosmic ray data related to 29.5 days, J. Geophys. Res. 69, 3965-3972.

L. Harang, The Aurorae (John Wiley & Sons, New York 1951),44

B. Haurwitz, Atmospheric Tides, Science 144 (1964), 1415-1422.

J.R. Herman and R.A. Goldberg, Sun, weather and climate, National Aeronautics and Space Administration (1978)

M. Lethbridge, Solar-Lunar variables, thunderstorms and tornadoes, Dept. of Meteor. Report, College of Earth and Mineral Sciences, Penn. State Univ., University Park (1969), 58 pp.

W.I. Linlor, Electric fields in space and on the lunar surface, in S. Coroniti and J. Hughes (eds), Planetary Electrodynamics, Vol. 2 (Gordone & Breach New York 1969), 369

R. Markson, Considerations regarding solar and lunar modulation of geophysical parameters, atmospheric electricity and thunderstorms, Pure and Applied Physics 84 (1971), 161-200.

F.F. Ness, The magnetohydrodynamic wake of the moon, J. Geophys. Res. 70 (1965), 517-534.

H.L Stolov, Further investigations of a variation of geomagnetic activity with lunar phase, J. Geophys. Res. 70 (1965), 77-82.

J.M. Wilcox and N.F. Ness, The interplanetary magnetic field, solar origin and terrestrial effects, Space Sci. Rev. 8 (1968), 258-328.


© Copyright: Michael Erlewine





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