Introduction. Zoroastrianism & Astrology

Detail of the painting School of Athens by Raphael 1509 CE. An artist's fanciful impression of Zoroaster & Ptolemy in conversation. Ptolemy (c. 90-168 CE) holds an earth sphere, backs the viewer and faces Zoroaster who holds a celestial sphere. Western Astrology is based on Ptolemy's Tetrabiblos. (There are no surviving images of Zoroaster and he lived long before Ptolemy's time.)
This site seeks to develop an understanding of basic astrological concepts and terminology from a Zoroastrian / Zarathushtrian perspective. It also serves as a companion site to this author's Zoroastrian Heritage site and Zoroastrian Heritage blog.

Ancient Zoroastrian Use of Astrology
Surviving Zoroastrian texts indicate that astrology was used by ancient Zoroastrians and their priests, the magi (see below), primarily as a method of measuring historical and calendrical time. They developed an astrology of the world and used astrology as a means to date events in Aryan history. The magi also used astrology to predict cyclical events such as seasons and significant climatic changes that would cause community-wide changes.

Today, some Zoroastrians also accept astrology as a means of predicting events or, say, to determine if two people are compatible. Other Zoroastrians reject such use relegating it to superstition. Regardless, astrology is an indelible part of Zoroastrian heritage. An examination of Zoroastrian astrology provides us with very interesting insights and historic connections regardless of beliefs.

Free Will, Choice & Circumstance
Since Zoroastrianism philosophy recognizes free will and a person’s individual and complete responsibility for her or his every thought, word and deed, it automatically rejects any suggestion that a person’s choice of thoughts, words and deeds were a result of movements of astral bodies in the skies. However, if this writer may be permitted to hazard an opinion about the place of astrology in such a philosophy, the orthodox Zoroastrian approach may be to seek possible answers to one’s lot in life or predicaments in astrology, while maintaining that within the boundaries of circumstance, an individual has the ability to make choices in every thought, word and deed based on free will and the orientation of her or his spirit – choices that have the ability to change circumstance. Astrology may be used to indicate potential rather than absolute fated destiny, or perhaps favourable and unfavourable timing to undertake a venture.

One way to understand the Zoroastrian approach to the interplay between providence and free will is to examine the concept of the khvarenah. The khvarenah is a particular talent or set of talents and with which everyone is born and which a person can develop through free will and then employ for good or evil to the extent of her or his ability. When employed for good, a person manifests one’s meaning in life. The khvarenah is also the archetype of what a person can grow to if allowed to grow to the limit of her or his capacity in grace; it is a person's higher calling – that person’s potential meaning in life. A person needs to recognize her or his own khvarenah. Sometimes people find their khvarenah, sometimes easily and sometimes after some searching. Once found, it can be however be lost - a person can 'loose' herself or himself if a person's spirit and commitment are not strong enough and if she or he is easily distracted especially by base ambitions. Latent khvarenah is therefore fated. It can even be considered a gift. What a person does with it is a matter of free will and free choice.

References to Astrology in Zoroastrian Texts
Role of Astrology in Zoroastrianism
There are no references to astrology in surviving Zoroastrian scriptures. However, astrology plays a prominent role in Middle Persian (8th to 10th century CE) non-scriptural Zoroastrian religious texts such as the Bundahishn (Creation) and Jamasp Namah (the Book of Jamasp, see below). These texts are based on earlier (now extinct) religious texts. The role of Astrology in Zoroastrianism is cultural and not religious. The cultural role is nevertheless deep-seated.

[In addition to astrological references in surviving non-scriptural Middle Persian texts, we find references in Arabic texts describing other Middle Persian texts that are now extinct. For instance, we hear of the Zik-i Shahriyaran of Yezdigird III and the Kitab al-Mawalid wa Ahkamiha (Book of Nativities and their Judgements) in Arabic language or Islamic texts. Indeed, the Kitab al-Mawalid wa Ahkamiha is the oldest treatise of genethlialogy that survives in Arabic. Genethlialogy is the science of calculating the position of heavenly bodies on nativities. The Arabic texts state this Kitab was written in the Din Dabirih, the Zoroastrian-Avestan script, by 'Zaradusht' (Zoroaster) himself - a most unlikely claim in the same vein as ascribing the authorship of the Oracles of Zoroaster to Zoroaster. The texts go on to state that the Kitab was translated from the 'language of Zaradusht' to Middle Persian by Mahankard ibn Mihrziyar for the marzban of Merv, Mahuyah ibn Mahanahidh in the year 637, the year in which Ctesiphon (now in Iraq) fell to the Arabs. Marzban means a general in charge of a border province. Mahankard ibn Mihrziyar is otherwise known as Mahoe, marzban of Marv and the son of Mahpanah. Mahoe/Mahankard is notorious in Zoroastrian history as being the man who betrayed the fleeing Zoroastrian king Yezdigird III to the Arabs around 642 CE. Mahankard's text was translated from Middle Persian into Arabic by Sa'id ibn Khurasankhurrah for the Mobed Sunpadh (isbahbad Sinbad) during the time of Abu Muslim (Sinbad was the reputed Majus/Magus of Nishapur who set out to avenge Abu Muslim's murder by the Caliph al-Mansur on February 12, 755 CE, but who was himself killed presumably by the Caliph's men). The introduction to the Kitab contains a horoscope that computes to an astronomical date of October 7, 549, at which time Iran was ruled by the Zoroastrian-Sassanian king Khusrau Anushirwan - an example of how astrology can be used to record historical dates. The body of the work deals with the technical details of interpreting diagrams illustrating horoscopes. It also discusses the effects of the sun in various astrological places, the haylaj (prorogator) and the kadkhoda, otherwise meaning the head or lord of a village) but in this case lord of the significant luminary's term, the dodecatopos (twelve astrological places), anniversary themes and the influence of selected fixed stars.]

The references to astrology in Middle Persian Zoroastrian texts are to the horoscope of the world, the zaych-i gehan (see the tab on this site), cosmology in general and the calendar. The Jamasp Namah also makes references to Jamasp, Zoroaster / Zarathushtra's successor as high priest, being a noted astrologer. The Qissa-e Sanjan, a text that describes the flight of Zoroastrians to India after the Arab invasion of Iran, does make several references to high priests consulting astrological charts to determine the best course of action during the flight of the Zoroastrians - Zoroastrians who came to be known as the Parsees of India.

The Poets Ferdowsi's 10th century CE epic, the Shahnameh, also makes references to the kings consulting astrologers who were at times the magi (see section on Magi below). The Shahnameh has the tradition going back to the beginning of history. One such reference relates to legendary reign of King Jamshed: "Then it came about that the heart of Jamshid was uplifted in pride, and he forgot whence came his weal and the source of his blessings. He beheld only himself upon the earth, and he named himself God, and sent forth his image to be worshipped. But when he had spoken thus, the mubeds (magi), who are astrologers and wise men, hung their heads in sorrow, and no man knew how he should answer the Shah." What followed was the beginning of the end of the first great tragic cycle in Aryan history - of a rise to great glory only to be followed by tragic times - and a historical lesson in the cause of the tragedy: that pride comes before a fall, together with the obverse lesson that if one seeks to be a king, one should seek to be a servant first.

In another story, Ferdowsi has the legendary king of Sistan (one of the Iranian-Aryan kingdoms) and a pahlevan (see our tab on Mithraeum and the image of pahlevans training in a zurkhaneh and our page on Parthians/Parthava), a champion of ancient Iran, asking the mubeds (the magi) to cast his son Zal's horoscope where they read that Zal would be a brave and prudent champion of Ayran (Iran).

Perhaps, the most direct reference to the application of astrology regarding destiny in stated in the 9th century CE Zoroastrian text the Denkard/Dinkard:

Dinkard 4.70A: The star-readers (i.e. astrologers) understand the worth of the allotment (of destiny by the stars).

Dinkard 4.71: The laws relating to these and other (astrological) details the astrologers learn from writings on the earth (i.e. from cosmology). Astrologers can foretell the good events of a man's (life) from his horoscope.

Non-Zoroastrian References to Ancient Persian-Zoroastrian Astrology
Some ancient and medieval references cite as their sources Zoroaster and the magi, while others cite 'Persian' sources. Zoroastrianism was synonymous with Persia prior to the Arab Islamic invasion of Iran c. 640 CE. Zoroastrian astrology survives in a number of non-Zoroastrian works such as those of Masha'allah ibn Athari, Abu Ma’shar al Balkhi, Al Biruni, al-Kamali and Abraham ibn Ezra.

According to author Courtney Roberts, "The astrology of the Magi experienced an enthusiastic revival in the work of the Islamic astronomers of the Golden Age of Baghdad (8th - 9th century CE). There, the upstart Abbasid caliphs, eager to legitimate their new dynasty, gladly adopted the Persian astrology of the Magi to their own ends, proclaiming themselves the rightful heirs to the imperial majesty of ancient Persia." The same can be said about the Ghaznivid rulers from (today's) Afghanistan. The significance of this adoption of Persian astrology by Islamic regimes, is the context in which the adoption happened: many Islamists believe astrology to be haram - a sin, something forbidden by religious edict (cf. Is Astrology Haram in Islam and Why?).

The Abbasids employed the services of Masha'allah ibn Athari (c.740–815 CE) Persian Jewish astrologer, to determine the propitious time for the founding of Baghdad which he determined was July 30, 762 CE. Masha'allah was then an astronomer resident in the city of Basra, a city that is located in the south of modern day Iraq. European translators of his work styled his name as 'Messahala'. He continued to have an influential position in the court of the Abbasids. According to E. S. Kennedy and D. Pingree in Astrological History of Masha'allah, Masha'allah ibn Athari relied heavily on Sassanian (Sasanian), i.e. Zoroastrian sources for his writings (Kitab al-Mawalid) and computations of planetary positions in casting horoscopes. To do this, Athari would have had to have a knowledge of the language of Sassanian literature - Middle Persian written in the Pahlavi script (cf. Essays on Islamic Philosophy and Science by George Fadlo Hourani).

Abu Ma’shar al Balkhi (Latinized as Albumasar, 787-886 CE) was an Eastern Iran from the ancient city of Balkh that was home to Jamasp and is today a part of Northern Afghanistan. His treatise on astrology written in Arabic is titled, Kitab al-Mudkhal al-Kabir ila 'ilm Ahkam an-Nujjum, was translated into Latin under the title Introductorium in Astronomiam and was written in Baghdad in 848 CE. As a Khorasani Iranian, Balkhi might have had access to now extinct Zoroastrian works. (cf. D. Pingree's The Thousands of Abu Ma'shar)

Al Biruni (973-1048) was another Eastern Iranian who was born Kath (near Khiva?), Khwarezm (now in Uzbekistan), and died in Ghazni, (in today's Afghanistan). His work in astrology Kitab al-Tafhim li Awa'il Sina'at al-Tanjim, also known as Tafhim, was translated by R. Ramsay Wright as the Book of Instructions in the Elements of the Art of Astrology (1934). His listing on the Twelve Houses closely parallels the Zoroastrian concept.

Rabbi Abraham ben Meir Ibn Ezra (also known as Abenezra, c. 1089 — 1164 CE). Ibn Ezra who in Spain when it was under the Muslim rule, wrote several books on astrology and cites Greek, Hindu, Persian, and Arabic sources. One of his books titled Se'fer Ha'Olam (Book of the World), discusses the Persian (Zoroastrian) astrology of Jupiter-Saturn conjunctions and the Firdar periods.

Western Understanding of Astrology’s Origins
While it is commonly understood that Western Astrology had it origins in Egypt or Babylon/Chaldea (Akkad), some classical Hellenic authors writing on astrology name as their sources – or even as astrology's 'inventors' – either the ancient Iranian (Persian) founder of Zoroastrianism, Zoroaster, or a Zoroastrian priest, the Persian arch-magus, Ostanes / Osthanes [Old Iranian (H)ushtana, see section on Ostanes below]. Zoroastrian and Eastern sources, however, mention Jamasp, a contemporary of Zoroaster as a noted astrologer (for references see Greek Perceptions of Zoroaster, Zoroastrianism & the Magi and Astrology & Zoroastrianism).

Some authors such as Courtney Roberts (The Star of the Magi) state, "It was the Persians who first developed the astrological use of the cycle of Jupiter Saturn conjunctions. ...These exotic chronologies travelled well, and made as profound an impact on astronomy and astrology in Judea and the Christian West as they did throughout the vast Moslem empire." Roberts also states that "We rarely acknowledge the far-reaching scientific and religious contributions of the Persians, the traditional enemies of our cultural heroes, the Greeks and Romans."

This sentiment has created a tenacious bias against acknowledging Persia or Iran as the source of any wisdom. The biblical nations extended as far east as Babylon and that is as far east many Western writers are prepared to go in their acknowledgements. If there is a choice to be made between Babylon and Persia or Iran as being the source of knowledge, Babylon is chosen by default even when the references indicate to the contrary. Take for instance the "Astronomical Chapter of the Bundahishn" in Acta Iranica, Volume 6, from JRAS, 1942, pp. 229-248. The author interprets a passage from the Middle Persian Zoroastrian text, the Dinkard, stating that Zoroaster explained the proper impact of the zodiacal circle to the wise of Babylon (frazanagan-i Babelayigan), as an acknowledgement that the Persians received this information from the Babylonians!! The bias and skewing of information is pathetic. [See our blog Zoroastrian-Persian Influence on Greek Philosophy and Science]

After the destruction of Persian texts by the invading Alexander of Macedonia and the subsequent liberation of Persia from the remnants of Macedonian rule, the Persians did go to Babylon and Egypt to search for Persian texts. This too is seen by some writers as proof that information flowed from Babylon and Egypt to Persia and not the other way around. [See our blog Ostanes - Persian Sage]

There is one primary indicator of the Zoroastrian-Iranian (Persian) calendar's role in the early history of the astrological calendars used today in the West: in a region dominated by the use of lunar calendars, the Zoroastrian-Iranian calendar stands apart as a solar calendar that started the year on the vernal equinox, March 21, Nowruz. That tradition is to this day celebrated in all the traditional Iranian-Aryan countries, the Central Asian countries, Iran, Azerbaijan and Kurdistan (parts of Iran, Iraq, Syria and Turkey). The vernal-solar calendar in entrenched in Zoroastrian literature and Zoroaster / Zarathushtra is reputed to have built and observatory based on the concepts on which the calendar was constructed and which determined the vernal equinox. The Zoroastrian Fasli (Seasonal) calendar based on the ancient precepts in the texts, is one of the most precise calendars in the world (see the Calendar tab); one calendar grid can be used perpetually and when the vernal equinox is determined by an observatory, it is self correcting for the solar calendar's factional days. The other link is through Mithraism which was the religion of Rome just prior to the advent of Christianity. One link between Roman Mithraism and old Iranian Mithraism is the solar calendar and its zodiac (see the Mithraeum tab).

It should be noted that due to the destruction of Zoroastrian texts first by Alexander of Macedonia and then by Arabs and successive regimes, much direct information on Zoroastrian history and philosophy has been lost and comes to us indirectly through Greek and Babylonian sources. For instance, medieval Zoroastrians had lost knowledge of Persian-Zoroastrian Achaemenian King Cyrus the Great (and for that matter most of Achaemenian history other than scattered references to King Darius the Great). Much of our information on King Cyrus comes from Classical Greek authors such as Xenophon, Herodotus and Strabo, from Babylonian inscriptions and even from the Jewish and Christian Bibles. In addition, modern archaeology allows us to reconstruct a lost and forgotten history.

Iranians (Persians) are in the unfortunate circumstance of learning their own classical-Achaemenian history through recycled accounts. The same holds true for Persian-Zoroastrian astrology and cosmology which was disseminated westward during Achaemenian times.

The Achaemenian Persian Empire included Babylon and all of the Middle East including Asiatic Greece. Colonies of Persians including the magi lived throughout the Persian Empire including Egypt. Babylon was close to the Persian Empire's summer capital Susa and was a capital of the ninth satrapy (imperial autonomous province). The Persians further developed Babylon into an international centre of learning and science. A number of surviving Babylonian and Greek works were written or acquired by the Greeks during Persian rule.

In this manner, much information while authored by Greeks and Babylonians, is Persian-Zoroastrian in origin, and many classical Hellenic authors acknowledge their source. In relation to astrology, they cite Zoroaster, Ostanes or the magi in general as their source. Zoroastrians have often be called magians.

Zoroaster (Zarathushtra/Zarathustra)
Zarathushtra (Zoroaster / Zarathustra)
An artist's impression. There are no
known images of Zarathushtra
According to the first century BCE Roman historian Trogus Pompeius, Zoroaster was the founder of the magian (see Magi below) science and knowledge of the stars.

Zoroaster is the Western Greek-based version of the original name Zarathushtra, also spelt Zarathustra in the West.

While there is a Zoroastrian tradition in astrology, Zoroastrians do not see Zoroaster (Zarathushtra/Zarathustra) as an astrologer. Rather, they see Zoroaster as a wise person who developed an integrated understanding of theology, philosophy, ethics, the sciences (including astronomy), health and order – in other words, active, meaningful, holistic, ethical, lawful living.

Unlike Greek sources, while Zoroastrian sources do not make the claim that Zoroaster was the 'inventor' of astrology, a few Zoroastrians texts do speak of Zoroaster as an astronomer and someone who built an astronomical observatory. One of the primary purposes of the observatory was to measure time, maintain a very precise calendar and predict the seasons and accompanying weather changes – in other words, applied astronomy. The calendar was used to make preparations for planting and harvesting crops; the time for taking animals to pasture or on pastoral circuits, and even the starting and ending of the caravan season for trading and travel journeys along the Silk Roads.

While the Zoroastrian calendar employed a zodiac, the zodiac was used to predict the equinoxes and solstices. The Zoroastrian year started with the spring equinox (commonly March 21). The resulting calendar was very accurate. Some writers state that this system of starting the year on the equinox produced an automatically self-adjusting calendar that did not need to rely on specified intercalary (leap) days but which were inserted automatically. The zodiac itself did come to be used in Zoroastrian cosmology and the astrology of the world.

Since in ancient times there was a very thin line - or no line at all - between astronomy and astrologer, since the magi were well-versed in astrology and since Zoroaster was considered to be the founder of the magian order, we can see that he very well have been labelled as an astrologer rather than an astronomer.

[For a discussion on the time when Zoroaster/Zarathushtra lived see Age of Zarathushtra (Zoroaster/Zarathustra).  For a further discussion on Zoroaster and astrology see Astrology & Zoroastrianism]

Rock carving at Museum
for Anatolian Civilizations, Ankara.
Possibly a magus carrying a baresman
bundle and haoma mortar/cup.
Strabo (15.3.14) describes the magi
of Anatolia as "holding in their
hands a bundle of slender myrtle wands."
The priests of Zoroastrianism, the magha or maga, were known to the Greeks as the magi (singular: magus). Plato (429–347 BCE) calls Zoroaster the founder of the doctrine of the Magi. According to one of Plato's disciples, Hermodorus, Zoroaster was a ‘Persian’ (all Iranians were called 'Persians' by the Greeks) and the first Magian. Zoroastrians were also known as Magians. Persia was a small but dominant kingdom of the Iranian federation of kingdoms - province (also see Iran and Persia, Are They the Same?) and therefore the Greeks called all of Iran, 'Persia' akin to called Great Britain, 'England'.

When the classical Greek writers refer to Zoroaster as an 'inventor' of astrology, they probably mean ancient Zoroastrian priests, the magi, who were the inheritors of Zoroaster's wisdom, and who during the era of the Persian-Achaemenian Empire (c. 600-c. 330 BCE) were renowned from the borders of Greece and Egypt to those of India and China as physicians, healers, astronomers and even astrologers.

In maintaining the tradition of astronomical observations and a resulting calendar initiated by Zoroaster, the magi became keen and systematic observers of the movements of celestial bodies.

Despite the attempts of a few Hellenic authors to belittle the magi by naming magic after their practice, the credibility of the magi as wise healers, physicians and seers was without parallel in the known world, so much so, that Christian tradition found it necessary to claim that it was the magi who found Jesus based on an astronomical observation that was prophesized by ancient magian astrology.

The head of the magi is sometimes referred to as the arch-magus or archmage. In Western literature this title has become synonymous with wizardry. It is greatly upsetting to Zoroastrians to see their noble religion denigrated in this fashion by mindless and ignorant individuals. Zoroastrian texts view deceptive wizards and gnomes/nymphs (jadugan and parigan) in a negative light. It is our hope that those who undertake a serious study will be able to discern fact from fiction and hyperbole.

Zoroastrians call the position of arch-magus, Mobed-e Mobedan. According to the Zoroastrian text the Jamasp Namah (the Book of Jamasp), as well as Western sources, Zoroaster was the first Mobed-e Mobedan and upon his passing away, that office was inherited by a noted contemporary, Jamasp. In Zoroastrian literature, it is Jamasp (and not Zoroaster) who figures prominently as an astrologer.

Jamasp (Gjamasp)
J. M. Ashmand in his 1822 translation of Ptolemy's Tetrabiblos, states, "Dr. Thomas Hyde, in speaking of this philosopher (Jamasp/Gjamasp), cites a passage from a very ancient author, having before told us that this author asserted there had been among the Persians ten doctors (magi) of such consummate wisdom as the whole world could not boast the like. He then gives the author's words: 'Of these, the sixth was Gjamasp, an astrologer..."

Jamasp was a contemporary of Zoroaster. He was the prime minister of Zoroaster’s patron king Vishtasp (later known as Gushtasp) and an early supporter and disciple of Zoroaster. Jamasp was renowned for his learning, immense store of knowledge and wisdom.

A medieval Zoroastrian text titled the Jamasp Namah (the Book of Jamasp) refers to Jamasp as ‘Jamasp the astrologer’. The text was written by a Rana Jesang in the style of the original and fabled ‘book’ written by Jamasp himself – a book on astrology and prophecy. The book was known in the West as Judicia Gjamaspis (Judgement of Jamasp) and was said to contain Jamasp’s 'judgment' on the great conjunctions of the planets "which had happened before his time, and which were to happen in succeeding ages" together with accompanying predictions of world events.

When the Greeks cite a book on astrology written by the arch-magus Ostanes, it was likely the book of Jamasp or a book based on Jamasp’s writings.

Ostanes or Osthanes [Old Iranian (H)ushtana]
Magi as astronomers. Image credit: Crystalinks
1st century author, Pliny the Elder (23-79 CE) names a Persian senior magus, Ostanes, as the person who developed the magicis (magical) arts, invented 'alchemy' and first committed the knowledge including Zoroaster's original verbal teachings (mostly in the form of verse) to writing. Astrology was an adjunct to the knowledge of the natural sciences. Pliny make Ostanes a contemporary of Achaemenian King Xerxes and who accompanied Xerxes (519-465 BCE) on his invasion of Greece. The credibility of Pliny's account suffers greatly when he makes Ostanes a contemporary of Alexander (356-323 BCE) as well.

According to Pliny Ostanes's introduction of the "monstrous craft" to the Greeks gave those people not only a "lust" (aviditatem) for magic, but a downright "madness" (rabiem) for it. In 30.2.8-10, Pliny goes on to state that many Greek philosophers such as Pythagoras, Empedocles, Democritus, and Plato traveled east to study the philosophy and craft of the magi and then returned to Greece to teach what they had learned from the Persian magi. Pliny notes that Ostanes was Democritus’ (c. 460–c. 370 BCE) teacher. Democritus was an influential pre-Socratic philosopher who formulated an atomic theory for the cosmos. Many consider Democritus to be the father of modern science.

The Zoroastrian texts we refer to above no longer exist. Zoroastrian texts have largely been destroyed by invaders such as Alexander and the Arabs. The one surviving Zoroastrian text that makes astronomical observations and describes the Zoroastrian zodiac is the Middle Persian text the Bundahishn writing after the Arab invasion of Iran and was based on surviving sources now lost to us.

The ninth century CE Middle Persian Zoroastrian text, the Bundahishn outlines Zoroastrian cosmology, cosmogony, astronomy, the zodiac, and the Zoroastrian calendar based on the zodiac (see link below) amongst other topics including history and geography.

The Bundahishn bases its information on prior texts written when the spring equinox (Nowruz or Newday) commenced when the Sun entered the first degree (khurdak) of Varak the ram (Aries in the West). If so, the system relates to one designed (or was last adjusted) at the commencement of the Age of Varak (Aries) some 2000 to 2200 years ago during the Parthian reign of Persia/Iran.

[Zoroastrian Astrology in the Bundahishn (pdf)]

Surviving Knowledge & Traditions
Today, the tradition of Zoroastrian astrology appears to have been largely lost and this author does not know of any modern Zoroastrian priest who practices astrology. To understand Zoroastrian astrology, we have but one surviving Zoroastrian text the Bundahishn (see above), scattered references in other Zoroastrian texts and scripture, Western Mithraic frescoes, Greek and even post-Arab invasion Iranian accounts of the Zoroastrian tradition.
A rock carving of the tauroctony from the Mithraeum in London. Note the circular zodiac in the ecliptic that surround the central image. If the central image is terrestial, then the ancients understood that the ecliptic encircled a round earth.
Despite the paucity of surviving texts, there are scattered but sufficient indications that Zoroastrian astrology or perhaps even pre-Zoroastrian Aryan astrology, may be an original discipline and one whose concepts survive in Hindu, Chinese and Western astrology.

For further details and references on the Greek accounts and perceptions on astrology and Zoroastrianism (or the magi - Zoroastrian priests), as well as Zoroastrian accounts, please see:
Zoroastrian Heritage at http://zoroastrianheritage.blogspot.com, or click the following
Greek Perceptions of Zoroaster, Zoroastrianism & the Magi
Astrology & Zoroastrianism
Zoroastrian Heritage website
Zoroastrian Astrology in the Bundahishn (pdf)
Zodiac at Encyclopaedia Iranica