The visible planetary bodies
Without the benefit of telescopes, astrologers and astronomers of yore relied on their obeservations of the Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn. Calculated invisible points of the Moon's nodes (Rahu and Ketu) were also studied due to their importance in explaining the astronomical phenomena of precession of the equinoxes and solar and lunar eclipses. In the ancient Western world, Hellenic and Roman astrology evolved based on the visible bodies as was the case in the Eastern world with Vedic astrology. The accompanying photo shows some of the visible planets in the early morning sky. Of note are Mercury and Mars who are faintly visible over the horizon to the right.
With advances in the science of telescopy, astronomers were able to discover other more distant bodies in our solar system, beyond the orbit of Saturn. In the fateful year of 1781, the planet Uranus was discovered. It is one-third the size of Jupiter but over four times as far from the Earth. Being also less than half the size of Saturn, Uranus is not visible to the human eye in the night sky. In 1801, puny Ceres in the Asteroid belt was discovered. It is one-fourth the size of our Moon, but much closer to Earth than Jupiter. In 1846, Neptune was discovered, which is similar in size to Uranus but almost twice as far from the Earth. Very distant dwarf planetary bodies have also been discovered. In 1930, the dwarf body of icy Pluto was discovered. It is around one-hundred thousand times smaller than Jupiter and over nine times as far from the Earth. The much smaller Sedna was discovered in 2003 at a 21 fold distance from Earth compared to Jupiter. Eris was then discovered in 2005, with similar features. Clearly, these tiny planetary bodies are way, way out there.
Size and distance determine visibility
The Earth is 12800 km in diameter and 150 million km (1 Astronomical Unit, AU) from the Sun. The Moon is 3475 km in diameter and only 385.000 km from the Earth. Aside from the Sun, the Moon is the largest disc to be seen from Earth, but only when it reflects the light of the Sun. The Sun is 1.4 million km in diameter and 150 million km from the Earth. It is the light- and life-giver in our solar system and the most clearly visible body by far. Of the other reflective bodies, Venus is 12000 km in diameter and 42 million km (0.3 AUs) from the Earth. It is the most visible of the planets. Mercury is under 5000 km in diameter and 92 million km (0.6 AUs) from the Earth. As Mercury and Venus are in an inferior orbit to that of Earth, their visibility also depends on their distance from the sun in orbit. Mars is 6800 km in diameter and 78 million km (0.5 AUs) from the Earth. The "Red planet" is beyond the orbit of the Earth but clearly visible. Jupiter is 143000 km in diameter, one hundred times smaller than the Sun, and 630 million km (4.2 AUs) from the Earth. Due to it being by far the largest planet in the solar system, it is more visible than the smaller planets closer to Earth, excluding the planet closest to us, Venus. Saturn, which is 120000 km in diameter, close in size to that of Jupiter but twice as far from the Earth, or 1.3 billion km (8.3 AUs), is also visible in the night sky.
By comparison, Uranus is 51000 km in diameter and 2.8 billion km (18 AUs) from the Earth and Neptune is 50000 km in diameter and 4.3 billion km (29 AUs) from the Earth. Neither of these planets is visible. Pluto is 2250 km in diameter and 5.7 billion km (39 AUs) away from the Earth, while Sedna has a diameter of 1800 km and is 89 AUs away. These dwarfs are not even easily detected with telescopes. Ceres is in the asteroid belt and is 900 km in diameter and 295 million km from the Earth. It is not visible, even if much closer.
The moon's of Jupiter and Saturn
We can also consider that there are many moon's in our solar system that are larger than the distant dwarfs and some are larger than Mercury, which is 5000 km in diameter! Compared to our own Moon, which is 3475 km in diameter, the moon’s of Jupiter, are quite large. Ganymede is 5260 km, Callisto 4800 km, Io 3630 km and Europa is 3140 km in diameter. Gallileo discovered these moon's in 1610 using a primitive telescope. Of Saturn’s moon’s, Titan is 5150 km in diameter and Triton is 2700 km. These moon's are also much closer to the Earth than the distant dwarfs but much further away than Mercury. Given their size and distance from Earth, these Moon's are far from visible on Earth. The close proximity of these moons to giants of the solar system likely has an effect to eclipse their influence on Earth.
Causality in astrology
Astrology has evolved over time as a symbolic language of the influences of the planets and the cosmos. Even if astrology is based on the influence of planetary bodies on human life, little is known about the actual causal mechanism. We do not know how the cosmic is having an effect on our experience in life or how it motivates our actions. It is a mistery, just like the law of karma is a mystery. However, we do know that the planets differ in size and distance, which affects their visibility or the pull of gravity on Earth. Moreover, we know that various influences have been detected through observation of human life by astrologers over thousands of years. At the same time, astrology is an extremely difficult field of inquiry as the stellar influences are highly complex. This makes it very challenging to isolate individual influences. That said, much progress has been made, such as embodied in the evolution of Vedic astrology, which is an integrated body of knowledge. One of the purest forms of Vedic astrology is the Systems' Approach, which has endeavoured to rid the age old astrology of accumulated contradictions and confusions, making it also easier to learn this ancient system of astrology.
Gravitation, as a force of nature, is not commonly well understood except in terms of what we experience here on Earth. In fact, gravitational force is considered a weak force in the universe. With enough thrust, we can escape from Earths gravitational field. That said, it is a sufficiently strong force for the Sun to keep other bodies in orbit and for planetary bodies to affect each other in orbit. The formula for gravitation force (F) between planetary bodies is
F = G * (M1 * M2/R*2)
the gravitational constant (G) multiplied by the product of the mass of two planets (M) divided by the distance between them (R) squared. The sub-scripts 1 or 2 indicate the planets.
A calculation of visibility
The attached table shows, the diameter of the planetary bodies and their distance from Earth, as well as a calculation of visibility. In the calculation we replace the planet's mass with its diameter. The results are broadly comparable to a calculation of gravitational forces. As the product of the mass of two planets is not used, the distance between the planets is not multiplied by itself. The table shows the ratio, which gives an indication of the range of influence, going from the highly visible Moon and Sun to the completly invisible distant dwarf bodies.
The accompanying graph shows that aside from the Sun and Moon, Venus is the most visible of the planetary bodies, followed by Jupiter, Saturn, Mars and Mercury, in that order. It is Mercury that is seen to be on the margin of visibility due to its small size. By comparison, the other planetary bodies, the moon's of Jupiter and Saturn, the planets Neptune and Uranus and the outer dwarf bodies are far from visible. This brings up the valid question if planetary influences are to a given extent proportional to their visibility or gravitational influences.
The detour of Western astrology
It has not helped astrology, that its rebirth in the West in the late middle ages resulted in a major detour from its historical forerunners as explained in the article Roman astrology in the ascendant. The result is that Western astrology is no longer a study of the mostly visible phenomena. As such, it has become removed from its intuitive and simple beginnings. Too often, one finds that rather than being rules-based Western astrology has evolved into a veritable free for all. When it comes to chart interpretation, in general it can be said that Western astrologers feel free to point to different factors without sufficient logical consistency. This is quite different from the Systems' Approach of Vedic Astrology, which is both a comprehensive system and relies on a scientific approach to astrology. Below, we can see four features of Western astrology where it has taken a major detour from its historical origins.
- Wrong zodiac used: by not correcting for the precession of the equinoxes, the calculated tropical zodiac has lost its original moorings with the visible sidereal zodiac. The ancient Hellenistic astrologers knew about the precession and adjusted the zodiac for it (Holden, 1996). Since the early middle ages Western astrologers have systematically fixed the zodiac to the Vernal point, giving rise to the tropical zodiac. As a result, the zodiac of Western Astrology is moving with relation to the fixed stars such that it is now 24° removed from the visible sidereal zodiac.
- Overemphasis on the Sun: the Sun has now become the veritable 'fixed star' of Western astrology. The starting point of the reading is the sun sign without relation to the house the sign Leo falls into. Moreover, many Westerners view themselves as being e.g. a "Sun in Leo", when they are in most cases with "Sun in Cancer" as per the visible zodiac. That said, in Vedic SA astrology Sun is recognised for its importance and interpreted according to its functional nature. Moreover, when other planets are placed in Sun-Like Houses (2, 3 and 9) or the sign Leo, they are considered stronger.
- Ascendant logic lost: the practice of Horoscopic astrology has largely been lost in the West. Hellenic, Roman and Vedic astrology all place a primary emphasis on the Ascendant. People are considered Aries if they have this sign in the ascendant. In Horoscopic astrology the focus in not on the sun-sign. Associated with this is the important logic that each house and its lord have a functional rulership, which is either positive or negative in the chart.
- Use of irrelevant bodies?: the discovery of distant bodies invisible to the naked eye has resulted in these bodies being readily incorporated into the practice of Western astrology based on the assumption that differences in likely influences based on gravitational force or visibility do not matter. These bodies are given major import in chart interpretation. This is possibly an error in assumption but more research is required to settle the matter.
Due to the above, Western astrology has evidently become a 'far out' art that has as a saving grace the original planetary influences. Some Western astrologers manage reasonably well despite this state of affairs. However, they labour at a disadvantage working with an astrology that has been stripped of the rising sign logic and the ordering or ranking of influences. Moreover, the horoscope interpretation is out of phase with the galactic background. Perhaps this explains why a majority of Western astrologers rarely emphasise accuracy of horoscopic interpretation or prediction. It seems many consider this original contribution of astrology, to make accurate predictions, as something that goes beyond what can reasonably be expecteted of today's astrology.
Science and astrology
It is a fact that modern Western scientists have, based on research of Western astrological practices, concluded that it is a 'pseudo-science' at best. This is a state of affairs that astrologers must confront. More importantly, Western astrology must find its way back into the academic research setting, as it has in India, where Vedic astrology (sk. Jyotish) is now being taught at the university level. The effort must be to get astrology 'back to basics' with the rigorous application of a scientific methodology. This is the only way to ensure that the symbolic language of astrology is built on a robust foundation. While the scientists have identified a weak spot, it is also true that in rejecting astrology based on superficial studies and a fundamental lack of understanding of the field they were studying, the scientists became guilty of prejudice. Their efforts to date have, regretfully, mostly been aimed at debunking astrology rather than exploring its potential. In other words, the scientists have already rejected the notion before researching it. Joseph Schumpeter termed such a bias the "pre-cognitive analytic act". Scientists, just like the astrologers, have a responsibility to determine the truth behind this age old knowledge of humanity. Scientists must perform their research into astrology with an open mind and knowledge of the detour of Western astrology.
It has been shown that planetary bodies in the solar system vary in terms of size and distance from the Earth. Some are visible to the naked eye while others are invisible. It is suggested that astrologers can usefully reconsider their astrological approach to see if what they assume is really correct in terms of accuracy of interpretation and prediction. Ultimately, if astrology is to have the kind of bright future that the visible cosmos invites it to have, astrologers must discard those techniques and assumptions that do not work. A good starting place for this inquiry is to carefully consider the likely importance of size and distance on astrological influences. A closer study of the historical origins of astrology is in order. Vedic astrology can be considered in this regard as it is the closest living relative to the astrology practiced in the ancient Greek and Roman world. More importantly, the final arbiter of the usefulnes of any form of astrology should be how accurate it is, both in terms of horoscope interpretation and prediction. If the predictions are based on clear logic and turn out to be accurate, the interpretations are likely also correct. If the predictions are not working out that well or easily explained in terms of astrological logic, then likely the horoscope interpretation is not of much value either. Vedic SA astrology is practiced consistently with the aim of accurate prediction and interpretation.
The views expressed are those of the author and should not be taken as the views of the Systems' Approach or its creator.
Planets and their mass
Calculation of gravitation force
James H. Holden, A History of Horoscopic Astrology, 1996
Astrology and science