Why I Practice Sidereal Astrology

I want to start right away with letting you know that I practice Sidereal astrology, not Tropical, and if I read your Sidereal chart to you, you may hear me say that your Sun sign is different from what you may have thought before. I want to let you know why I follow Sidereal instead of Tropical.

Tropical astrology is the form that is most commonly used in Western culture. Most of what you’ve been taught about Tropical astrology still applies to Sidereal, except that we calculate the sign positions based upon where they actually appear in the visible sky.

What happened is that around 2,400 years ago the widespread use of calendar systems was becoming common in many cultures across Europe. At that time an astrologer called Ptolemy suggested that the signs of the zodiac should be attached to specific calendar dates so that year over year everyone would agree, “Oh, April 22, for example, that’s when the Sun moves into Taurus, and we’re just going to leave it that way forever.”

That system simplified things at the time so everyone could get on the same page for a while. 2,400 years ago, the calculations were accurate, but nothing stays fixed.

The Moon, for example, isn’t a 28-day cycle. It’s a 28½-day cycle. We can’t just say, “Oh, the full moon is on the first day of the month” because you can go outside and look at the visible sky and see whether it’s a full moon or not.

Same principle applies to the signs. We can’t just say, “Oh, this sign will begin on this date forever” because it doesn’t.

This may sound technical, but there’s a phenomenon called "precession" which refers to a change in the direction of the Earth’s rotational axis.

This means our Earth’s axis wobbles. Because of precession, the signs in the visible sky actually advance about 1 degree every 72 years. So for 72 years,

Ptolemy’s system worked fine, but as centuries passed, that 1 degree of change began to add up, and Tropical astrology sign calculations are off now by almost three weeks. I think that's a big difference.

You can prove this to yourself, too. As of today, Tropical astrology is saying that our next new moon will be in Scorpio. But if you get a star app on your phone and set the app to Sidereal, which is the actual visible sky, you can go outside and point your phone at the Moon, you’ll see that the Moon is actually entering Leo. It's important to know this because the energy of Leo is a lot different from the energy of Scorpio.

When I first learned that my Sun sign is Sagittarius and not Capricorn, I was actually a bit resistant, too. I’d been overhearing all these traits of Cap and I’d unconsciously almost been trying to live up to the traits of earthy Cap -- commitment, dedication, hard-working, responsible.

But on my birthday I took my phone outside, pointed the app at the Sun, and sure enough, the Sun was in Sagittarius.

The more I got used to the idea of Sagittarius, the more sense it made to me because of how I show up. Sag is a fire sign, and what really matters more to me is purpose, adventure, exploration, philosophy, being free-spirited.

What’s funny to me is that my own reaction to learning my Sun sign wasn’t what I’d thought is actually an example of why I also think Tropical still has validity. Tropical astrology knowledge is widespread and by now it’s in the Collective. Everybody knows about it.

People overhear things about the sign they think they are, and we unconsciously internalize what we hear. So I absolutely admit that Tropical is a totally legit system when it’s used in the context of its intended purpose.

And there’s another thing. Size matters. You know that a circle is 360 degrees. Tropical astrology makes each sign an even 30 degrees because it’s easy to divide 360 by 12. But the signs in the sky are not an even 30 degrees. Virgo is huge, Pisces is huge, and Libra and Cancer are smaller. Sidereal astrology uses the actual size of the signs in the sky.

When I’m looking at a planet, I want to look at it exactly where it really appears in the sky.

Considering all this, my own personal thought is that when I’m reading a person’s chart, I want to read it based upon where the stars actually are in the visible sky because it’s important to know whether the Sun is actually in Cap or in Sag and how long it’s gonna stay there (size of the constellation!).

It’s important to know whether the Moon is actually entering Scorpio or it’s entering Leo. Otherwise, to me, the calculations are just off. And I want to be right on.

Aloha.