The Fallacy of the
trans-Saturnian Planets

Page 4
1 2 3 4

Planetary Diameters in the Surya-siddhanta

Dr. Richard Thompson has discovered in Surya-siddhanta, evidence which strongly suggests that this text was based on advanced astronomical knowledge. We shall not discuss his work in great detail, readers are invited to read it, we shall simply touch on cogent points.

His paper (Planetary Diameters in the Surya-siddhanta PDF) discusses a rule given in the Surya-siddhanta for computing the angular diameters of the planets (Mars, Mercury, Jupiter, Venus and Saturn). By combining these angular diameters with the circumferences of the planetary orbits listed in the text, it is possible to compute the diameters of the planets. When these computations are carried out, the results agree surprisingly well with modern astronomical data. He discusses several possible explanations for this and hypothesizes, that the angular diameter rule in the Surya-siddhanta may be based on advanced astronomical knowledge which was developed in ancient times but has now been largely forgotten.

In Surya-siddhanta 7.13 the following rule is given for calculating the apparent diameters of the planets Mars, Saturn, Mercury, Jupiter and Venus:

"The diameters upon the Moon’s orbit of Mars, Saturn, Mercury and Jupiter, are declared to be thirty, increased by half the half; that of Venus is sixty."

The meaning is as follows: The diameters are measured in a unit of distance called a yojana, which in the Surya-siddhanta is about five miles. The phrase "upon the Moon’s orbit" means that the planets look from our vantage point as though they were globes of the indicated diameters situated at the distance of the Moon. (Our vantage point is ideally the center of the earth.) Half the half of 30 is 7.5. Thus the verse says that the diameters "upon the Moon’s orbit" of the indicated planets are given by the series 30, 37.5, 45, 52.5, and 60 yojanas, respectively. The next verse uses this information to compute the angular diameters of the planets.

Thompson goes on to explain how this generates a new series of numbers 2, 2.5, 3, 3.5 and 4, which represent the angular diameters of planets according to Surya-siddhanta. These numbers do not agree well with modern measurements of the angular diameters, but Thompson convincingly demonstrates that these numbers can be interpreted in another way with the aid of other verses in the Surya-siddhanta, namely verses 12.85–90. These verses give the circumferences of the planetary orbits. Using this information Thompson is able to generate the diameters of these five planets. On comparison of the values generated by the Surya-siddhanta with that of modern values he found that they agree very well, much more than one would expect by chance.

How was it possible for the ancients to so accurately calculate the diameter of the planets? The Surya-siddhanta value for the diameter of Saturn is 73,882.09 while the modern value is 72,000 a difference of only 2.61%. We agree with Dr. Thompson that such accuracy implies that the Surya-siddhanta is based on advanced astronomical knowledge which was later forgotten.

The point of bringing this up in a general discussion of the use of trans-Saturnian planets in astrology is as follows: It would certainly appear from Thompson’s discovery that ancient peoples had more knowledge of celestial mechanics than we give them credit for. To be able to accurately determine the physical diameter of the most distant of the visible planets, Saturn, is an accomplishment of relatively modern times, the 18th century.

It seems intuitive that if the ancients could so accurately measure the diameters of the visible planets, feats only accomplished in recent times, then they must also have been aware of Neptune, Uranus and Pluto. But there is no indication of this anywhere in astronomical or astrological texts. Dr. Thompson personally showed me that if one tries to extend the rules given in the Surya-siddhanta to cover Neptune, Uranus, and Pluto they fail miserably. This suggests that the reason ancient Vedic astronomical texts focused on the visible planets was because these planets were of importance for astrology, not others. And, in fact, until modern times astronomy was pursued solely for the sake of astrology, therefore, it would make sense that if you only considered certain planets of significance in divination, then you would only need to calculate the position of those planets and not others.

Fallacy of Excessive Hypothesis

In summary we can say that the introduction of the trans-Saturnian planets and other space-detritus violates Occam’s Razor: Entia non sunt multiplicanda praeter necessitatem.

"No more things should be presumed to exist than are absolutely necessary."

Thus, the Western astrologers are guilty of the fallacy of excessive hypothesis. This fallacy of excessive hypothesis has arisen because Western astrologers, and those who slavishly follow them, have not understood the fundamental Vedic concept of graha (divinatory agent) as distinct from loka (physical planet). There is a beautiful simplicity, internal logical consistency and elegance in the philosophy of Vedic astrology that the introduction of other planets would destroy. The assignment of planetary periods, Lordships of signs, aspects, etc., the whole axiomatic base of Vedic astrology, would all be askew by tampering with the divinatory mechanism. Just as the addition of new letters to Sanskrit, or the addition of lines to the original six of the I Ching is unthinkable, it is absurd, unnecessary, and irresponsible to add additional planets to Vedic Astrology. The addition of extra planets violates the guru-parampara. It is the prime directive of a bona fide disciple to uphold the teachings of the guru-parampara. In practice, it is found that no advantage accrues by adding extra planets. The only thing that increases is confusion. The traditional Vedic school is based on a logical system of limited axioms. Whereas the Western school whimsically adds things without concern for the welfare of the internal consistency of their system . If someone really feels the need for more planets in Vedic astrology, then they should employ the upa-grahas and kala-velas. Those who feel compelled to use the trans-Saturnian planets should not call themselves Vedic astrologers, for by doing so, they do a dis-service to serious Vedic astrologers and bring disrepute unto a venerable tradition.

While we do offer services on this site it is primarily educational. Any money that we make from our services go toward continued study and publishing of well-researched articles that set a high standard in the jyotish community. As a brahmana my primary vocation is to study and share my knowledge with others. In traditional Vedic culture the general public and especially those who benefit directly from that knowledge help to support the teacher so that he can spend more time in deep study and continue the cycle. If your knowledge has been expanded and you are inspired by the Lord in your heart please donate an amount that you are comfortable giving.


Howe, Ellic, 1984, revised edition, Astrology and the Third Reich, UK: The Aquarian Press.

Ponde, Shil, 1939, Hindu Astrology, Joytisha[sic] Shastra, New York, NY: Larwood Publishers.

Thompson, Richard, 1993, Alien Identities, San Diego: Govardhan Hill Publishing.

Thompson, Richard, 1996, Planetary Diameters in the Surya-siddhanta, Journal of Scientific Exploration.

Wilhelm/Baynes, 1950, Third Edition 1967, reprinted 1984, The I Ching, Bollingen Series XIX, Princeton, New Jersey: Princeton University Press.

Williams, M. M., 1899, second reprint 1981, Sanskrit-English Dictionary, New Delhi: Munshiram Manoharlal.

Page 4
1 2 3 4