Skyscript Astrology Forum

The Years of the Planets are a doctrine first seen in Valens which as the list was developed over time grew into four separate categories for each planet: lesser, middle, greater, and greatest years. The first three are used in natal longevity calculations and the latter to determine the length of dynasties and countries.

From what has been published regarding the lesser years, the years represent the least common multiple of two separate cycles with the Sun's 19 lesser years corresponding to the Metonic Cycle the most well known.

Middle years are the average of lesster and greater years with some variation for the Moon and Sun.

Greater years, at least for the five planets/wandering stars, correspond to the sum of each planets' egyptian bounds across all the signs but no rationale for the greater years has been given other than one by Valens which has not been mentioned by any other author.

Greatest Years for mundane purposes are also not as well worked out other than for the Sun's greatest 1461 years which is the least common multiple of years when measured in 365 days and 365.25 days. It is known as the Sothic cycle. The Moon's greatest 520 years I have no idea nor have I found any decent rationale for the Sun and Moon's 120 and 108 major years.

What I have learned is this: and forgive me if it has been already pointed out somewhere else (but surprisingly I can find no reference to it among astrological forums).

The Greatest Years of the Planets are Babylonian in origin, based on planetary periods discerned through observation, primarily from addition of smaller planetary periods which were used to write goal-year texts. Though the Babylonians did not construct nor consider the Greatest Years of the Planets necessarily as a least common multiple of two different cycles, effectively this is what these numbers represent

Saturn
256 synodic = 9 sidereal = 265 years
Jupiter
391 synodic = 36 sidereal = 427 years
Mars
133 synodic = 151 sidereal = 284 years
Venus
720 synodic = 1871 sidereal = 1151 years
Mercury
1453 synodic = 1914 sidereal = 461 years

Note that these solutions are not perfect integers to the nth decimal place, but they are reasonably close.

Mercury has the greatest variability of years because there are quite a few other solutions which include 46 and 480 years.

This material has been around for quite a long time (since Neugebauer in the 1950s) but unless if I am missing something here I have not seen the attribution of the Greatest Years of the Planets to these Babylonian planetary periods.

A couple of questions for the group.
1. The first time I have found the Greatest Years of the Planets to appear in the astrolgocial literature is with Rhetorius who is a late compiler. Why was this section of Babylonian astronomy neglected from the Greek tradition for so long? What I am wondering is if the Greatest Years of the Planets somehow were transmitted to India and then recycled back to late Roman Era when Rhetorius picked it up right before Mashallah and Abu Ma'shar picked it up in the early Arabic tradition.

2. I have found one instance of their actual usage by astrologers - I have seen reference to a source (not the original) of Abu Ma'shar linking Jupiter's 427 Greatest Years to the duration of the Sassanian Empire which was a fairly close match. Are there any other attested references by astrologers which link the Greatest Years of the Planets to actual durations of kingdoms?

3. Besides clueless on the Moon's 520 Greatest years (though note it is 2 * 260 which is one of the Mayan cycles), I am also having problems finding a source for the Sun and Moon's 120 and 108 major years. I have looked through the Indian yugas and can't find anything persuasive thorugh would welcome other observations. Also the 108 is 4 * 27 Nakshatras (but not obviously twenty eight). In fact after attending one of the popular '108 sun salute' yoga sessions often conducted during summer and winter solstices here in the states, I was given a handout with over 50 different uses and applications in answer to the question "why 108?" This again leads me to wonder if there is any Indian chronological influence on the years of the planets for the Sun and Moon in the western system. Within the western system, the only thing I found is the interval of 54 years, or half of 108, which is the Exeligmos eclipse cycle which was modeled within the Antikythera mechanism now dated c. 205b.c. by recent work on the Saros dial.

For those looking for references on the Babylonian Planetary Periods, here are four, the 2nd of which is a well written PhD thesis I would recommend as a good start. There is actually quite a bit of material available on this

http://www.jstor.org/stable/3143671?seq ... b_contents

http://etheses.dur.ac.uk/101/1/A_Study_ ... ronomy.pdf

http://www.academia.edu/2361085/Goal-Ye ... _Phenomena

http://www.maa.org/publications/maa-rev ... he-planets

Thanks for any ideas.

There is some discussion on this by Deb here - pages 5,6
http://www.skyscript.co.uk/pdf/CA_pages_57_68.pdf

RegulusAstrology wrote: The Moon's greatest 520 years I have no idea nor have I found any decent rationale for the Sun and Moon's 120 and 108 major years.

There is a statement somewhere about 120 degrees being the most (in oblique ascension/descension) that the Sun can travel between the ascendant and midheaven or midheaven and descendant. This assumption is obviously incorrect from a mathematical standpoint. As for the 108, I've seen 2 different rationales:

1. That 12 degrees are subtracted from the Sun's greater years (120) because this is how far the Moon travels in 1 day to reach first light after a new Moon.

2. That if you take the period of Capricorn (opposite the Moon's domicile) and do quarters of 27 for Saturn one gets 27 * 4 = 108. This one comes from Valens.

Hi Regulus Astrology,

As to the Sun and Moon's 120 and 108 years, Zoller has some interesting thoughts. I refer you to his Diploma Course Lesson 10 - "An Examination of the Years of the Planets."
He quotes the christian bible about the 120 years, says the Moon's years are 9/10 of the Sun and mentions the 12 and 10 combination. While I cannot presently explain why 120, it is a crucial number for sure.

In the Four Pillars of Destiny branch of Chinese Astrology, aka BaZi, the solar calendar is used as a rule, even though sometimes the lunar one gives better results for certain charts born on the border between 2 months. When charting the Luck Pillars, which are the analogue of the predictive techniques in Ancient Astrology, 1 month (made of a Stem-Branch combination - for instance the Yin Wood Goat) shows 10 years of life. Thus 12 months equal 120 years of life - the years of the Sun. This is valid for both male and female nativities even though they are generally calculated and read differently.

Also, there are 10 Stems and 12 Branches in Chinese Astrology.
And of course there are 22 Major Arcana in the Tarot, which some say the first 10 show the physical plane and the next 12 the astral and above ones.

I think Rumen Kolev will know the answer to these questions.

As for Abu Mashar, I have read how he makes predictions for 220 and 320 years about a kingdom and even though he mentions some parts of the chart, he does not say how he arrived at those years. While they do not correspond to the greatest years of the planets, they could be close enough when one uses the 1/2 and 1/3 ratio as per Valens book VII, especially when one is dealing with such long periods.

Thanks for the all the replies, and to Vasanth for pointing out Deb's footnotes to her annotated version of Christian Astrology which links the Greatest Years to Babylonian Planetary Periods.

A few things I have picked up since making the original post.

On 120 as the Sun's major years.

Al-Biruni in Chronology of Ancient Nations, tr Edward Sachau, bottom of page 12 of the text (or page 29 of the pdf that I found) indicates the Persians used 120 years as an intercalary year. That comparing the 365 day Egyptian year to the solar year of 365 1/4 days and 1/5 hour that after 120 years the missing 1/4 days summed to 30 days and the missing 1/5 hour summed to a full day. They added 31 days in year 116 to make the adjustment.

Another intercalary method Biruni mentions next, top of page 13, also the Persians, based on a calendar year of 360 days with each month 30 days. Every 6th year another month was added and at the end of 120 years two additional months were added.

On 25 as the Moon's minor years.

I think it's worth noting that though we can talk about many of these periods as the least common multiple of two different cycles, sometimes the synodic and the sidereal, this is not really how the Babylonians thought of the data. As for the Greatest Years, which in some cases appear the sum of smaller periods used to make Goal-Year forecasts, their data was based on cycles of reappearance of heliacal rising, setting, stations, and the evening rising of superior planets just after opposition. Neugebaer named these events "Greek Letter Phenomena" which is terminology still used by scholars in the Exact Sciences. From what I have read (and correct me if wrong), it does not appear the Babylonians associated the Greek Letter Phenomena as events occuring on some type of circular orbit with epicycles like the Greeks later did.

Also the Babylonians appear to have worked primarily in the sidereal system. What this means is that the notion the Moon's 25 minor years are accounted for 309 synodic cycles in 25 Egyptian years of 365 days each may or may not be the true rationale behind the Moon's 25 minor years.

As an alternative: consider that the Babylonians worked with years with both 12 and 13 lunar cycles. If one takes the 12 lunar cycle year, then an even 300 synodic revolutions equals 25 of years computed as 354.3671 days. Would not an even 300 be just as an acceptable computation for scribes doing math in their head? Remember Babylonian math is base 60 which means '5' equates to 300 in their math system.

On the planet's Major Years

Other than the sum of a planet's bounds/terms across all signs is the planet's major years, this still remains a mystery. I do have a couple of calculations to share on this however which are very preliminary.

Back to the idea of working with both 12 and 13 lunar cycle years.
12 lunations = 354.3671 days. (sidereal)
13 lunations = 383.8977 days. (sidereal)

Let's look at Jupiter

Two of the smaller goal-years for Jupiter were 12 and 71. But supposing as a Babylonian scribe starting to apply these figures for longevity estimation for Jupiterian individuals and you noticed that Jupiter-individuals lived longer than 71 years. What would you do?

Well one might do quite a bit of experimenting and they certainly have a few hundred years to play around with the data.

Instead of using Egyptian years or even the mean solar year, why not see what happens if one measures Jupiter's sidereal period of 4,332.59 days in years based on 13 lunations:

4332.59 / 383.89770 * 7 = 79.00 = Jupiter's 79 major years. correct

Nobody, even me, is saying that 79 corresponds to an astronomical cycle. It's purely an accounting artifact when measuring time in units of years based on 13 lunations in a year.

For Saturn,

10,759.22 / 383.8977 * 2 = 56.05 ~ Saturn's 57 major years. It's off but is closer than using Egyptian years which gets you to 58.96 (error almost 2 years)

This doesn't work as well for Mars or Venus. In fact for Mars using the 13 lunation year, the increment of 68 as an even integer stands out over 66 as Mars' major years.

For Mercury,

back to Egyptian years, yes 83 sidereal cycles of 87.969 days yields an even 20 Egyptian years. But if we switch now to the 13 lunation calendar of 383.8977 days, then the same 83 sidereal cycles * 4 = 332. Applying 332 cycles of years of 383.8977 yields 76.08 which is reasonably close to Mercury's 76 major years.

I am not sure if these results are statistical artifacts generated from a confirmation bias, but would not rule them out. What I plan on doing is getting more into Swerdlow's book (4th reference of the original post) who does a good job of stepping into the shoes of the Babylonian scribes and trying to figure out how they did what they actually did with their tools and worldview - without our modern abilities to synch up sidereral and synodic periods in an Excel spreadsheet.

Will report back - probably a couple of months or even a year as I have limited time to devote to Swerdlow's book right now.

Thanks again for the comments and I look forward to other observations that anybody else has to share.

As for Abu Mashar, I have read how he makes predictions for 220 and 320 years about a kingdom and even though he mentions some parts of the chart, he does not say how he arrived at those years.

Would you be so kind to reveal what Abu Ma'shar's work you're referring to?
Thank you.

Regards,
Goran

220 years is the time of a shift in the jupiter/saturn conjunctions from one element to another via sidereal years.. not sure what the basis for the other cycle is and don't know what book zagata is getting that from... astrology of the world volume 11 perhaps?

It may have to do with fractions of Dawr a period of 360 years ruled by a sign and a planet.

Goran

Found one explanation of the planet's major years in Liber Hermetis:

Saturn = 30 (Aquarius - half of half of Sun) + 27 (Capricorn - half of half of Moon) = 57
Jupiter = 60 (Sagittarius - half of Sun) + 19 (Sun's lesser years) = 79
Jupiter = 54 (Pisces - half of Moon) + 25 (Moon's lesser years) = 79
Mars = 54 (half of Moon) + 9 (half of Sun's 18 ??) = 63
Venus = 54 (Taurus - half of Moon) + 30 (Libra - exalted ruler Saturn - Saturn's Aquarius portion ) = 84
Mercury = 57 (from Saturn) + 19 (Sun's lesser years) = 76

See section XXIII. Exposition of the Five Planets to whom are allotted the
Greater Years for details

Vasanth

If the planetary (''lesser'') years were conceptualized in the Egyptian 365 day civil calendar, why do Valens and modern Hellenistic astrologers use 360 day year for something like Zodiacal Releasing? Shouldn't the planetary years also be 365 days (but not 365.25)?

For up to about the fourth year, following the number which belongs to the quadriennium, the moon takes over the age of infancy - Ptolemy, Robbins translation

The Anonymous says that four years is assigned to the moon because after a period of that length its phases again occur in the same degrees.

Thayer's Note: The anonymous commentator, or this interpretation of him at least, is mistaken. The return of the moon to the same phase at (very close to) the same degree does not occur every 4 years — but every 19, the so‑called Metonic cycle; as can be verified by inspection of any ephemerides. - http://penelope.uchicago.edu/Thayer/E/R ... /home.html

Actually the Anonymous is correct, the quadrennium is connected to another cycle involving phases - the Octaeteris. Every four years, the Full Moon occurs in the degree diametrical to the previous New Moon and in eight years you have the same phase occuring ± 1 or 2 days/.

Interestingly the octaeteris is in harmony with the years of Venus, both stars being nocturnal (similarly it is only half harmonic with Mercury, for he is neutral in sect, or with Jupiter since it is diurnal).

Because the ancient Egyptians used a 365 day year, the octaeteris was basically a metonic cycle-like. The cycle covers 8 x 365 or 2920 days, thus 99 lunations coincide with that number. When the length of the year was thought 365.25, the number of days became 2922 thus the cycle lost value compared to the more descriptive metonic cycle.

Thus the Moon has 27 sidereal day months and 4 years and when multiplied you have 108 years. The Sun has 30 day months and multiplied by 4 you have 120 years instead, and you multiply by 4 because there are four seasons.

Ptolemy alludes to this principle as well, when he says that the ages of man seem to pass through the four qualities which coincide with the seasons. Thus the 120th year was thought death-bringing. Valens too, says there are four motions, four elements, four winds and four quarters of the Moon - new, first, full and second quarter.