Same Stars, Different View: The differences between Sidereal and Tropical Astrology

By Hayley White

Reading time: 7 minutes

Almost every country in the world is familiar with an astrological system, so it only makes sense that there are varying ways to interpret the stars. For example, in the West, the system of astrology followed is called tropical astrology, developed by the Greeks and Romans. The astrological system called sidereal astrology developed by ancient Egyptian, Persian, Mayan, and Vedic cultures is something completely different.

Tropical and sidereal astrology are two of the best-known methods of prophesy, and for good reason! Both play very important roles in the astrology landscape today.

By Hayley White

Reading time: 7 minutes

Almost every country in the world is familiar with an astrological system, so it only makes sense that there are varying ways to interpret the stars. For example, in the West, the system of astrology followed is called tropical astrology, developed by the Greeks and Romans. The astrological system called sidereal astrology developed by ancient Egyptian, Persian, Mayan, and Vedic cultures is something completely different.

Tropical and sidereal astrology are two of the best-known methods of prophesy, and for good reason! Both play very important roles in the astrology landscape today.

I spoke with Colleen Coffey, vice president of the New Zealand Astrology Foundation Incorporated (AFI). The AFI is New Zealand’s only astrological organisation and one that Colleen has worked with for a number of years. When I asked her what the difference between the two methods was, the first answer that came to her mind was that they are different in every way possible. “They are both different in how they’re read because of the distinctions between the two zodiacs: the interpretation is different, and it works from different principals,” she tells me.

Probably one of the main reasons these two astrological systems are so diverse is how they chart the stars in relation to the Earth. When the tropical system was created around 2000 years ago, a fixed astrological map was implemented that charted the stars’ positions in the sky as they were at that point in time. Tropical astrology has progressed in relation to that fixed map, rather than the stars’ actual position. It is also based off the Earth and the seasons and because the seasons have never changed, neither has tropical astrology.

The sidereal system, however, is based on the current position of the constellations in relation to the Earth. This means that the sidereal system has changed 1 degree every 72 years (the tropical system remains the same even as the stars move). These explanations and perspectives are deeply rooted in culture and have evolved as such.

The history and culture of Western astrology is well known, dating back to the Mesopotamian civilisations, and possibly earlier. The development into Greek, Roman, and Egyptian astrology is also very well documented, especially when all three merged into Ptolemaic astrology. Ptolemy was the first to really collate all astrological knowledge in one place and his system has since been the basis of Western astrology.

As for sidereal astrology, there was a point where the two astrological approaches were one and the same, around the 3rd or 4th century BC. Past that point, the two became separated and took off in opposite directions. Emerging from the ancient Sanskrit texts called the Vedas, sidereal astrology was born of the belief that the universe influences our individual lives, typically summed up by the saying “as above, so below”.

The two systems of astrology are also used for two completely different things, Colleen tells me. “Opposed to sidereal astrology which is generally a little more predictive and very black and white, Western astrology – particularly modern Western – has become more psychological,” she says. “This is the way they do it. If you are born with Saturn conjunct with the moon, or you’ve got the nodes Rahu (North Node) or Ketu (South Node) here, you will be … and that’s it. ‘You will be … ; you are going to … ; this will happen … ’,” she explains.

“Now, traditional Western astrology was like this too. In the beginning, traditional Western astrology was basically not used for common people but was reserved for countries and kings. It was ‘The king will lose his head on the 14th of March’. Sidereal is still very much like that, it’s authoritarian. In many ways, it’s truer to what astrology once was.”

In this way, the two astrological systems are linked to two defined aspects of our cultures. For example, Colleen says the cultures that use the sidereal system only look for three (fixed) things: when someone is born, when they are married, and when they die. In comparison, modern Western astrology leans more towards guidance, using words like ‘maybe’ or ‘inclined to’ or ‘tend to’.

“In the olden days when I used to do readings, people would come to me, and they really wanted me to tell them something. Very often you go to a sidereal astrologer, and they say, ‘Your marriage is going to break, he is going to leave you for a younger woman’ and that’s it. In my situation, I’d say, ‘I think you need to communicate with your partner because I can see your relationship is under stress. Perhaps you would like to come and see me both together’.”

But how would the two systems fare if they were merged together?

Created by Hungarian astrologer and philosopher Orosz László Wladimir, the synoptical astrology system aims to combine these very different astrological systems – tropical and sidereal – and use them simultaneously. It does this while also taking into account the position of the zodiac constellations.

Photo: Constellarius – Own work, CC BY-SA 3.0, Wikimedia

The synoptical chart has three circles that all hold a special significance and specific meaning. The inner circle is the tropical chart, representing the destined life path and the psychic and physical body, as well as the waking state. The middle and outer circles are the sidereal and constellation charts; they represent the spiritual body and the dream state.

Because the constellations between tropical and sidereal are not split equally, the synoptical chart divides them in a unique way. Each sector is portioned into the northern and southern regions by the ecliptic plane (which means that a planet on the southern ecliptic plane will enter Taurus before any of the others in the southern region). Each sector is opened by the first star belonging to a constellation and ends in the first marker of the next constellation. As for the aspects: the synoptical astrology system gets really technical, bringing in arithmetic to divide the circle.

When asked whether Colleen thought sidereal and tropical astrology could work together well within synoptical astrology in a way that makes it easy to use, her immediate answer was no, because the two systems are so contrasting and work in completely disparate ways.

“And why would you?” Colleen Coffey asks me. “I think it’s denying the individual tradition and use of both systems. Sidereal and tropical done by the right people will come to the same end. They go down different roads to get there, and for this reason I do not believe in mixing them. They came from the same core, but they’ve split away too much to bring them back together. Treat them with the respect they deserve.”

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