Declination refers to a way of measuring the position of the planets that’s different from what you’re used to seeing in the “regular” chart wheel. The chart wheel only represents one measurement, which is the planet’s longitude projected onto the ecliptic. So the regular chart wheel we all use is a bit more of a flat or 2D representation than a 3D one.
In contrast, declination measures the planet’s latitude in reference to the celestial equator, which is a representation of the earth’s equator projected onto space.
Carolyn Egan once explained declination simply and clearly. Picture the equator. Now extend the equator into space in your mind. Declination measures north and south of that line.
There’s one more term we want to learn here, and that’s right ascension. Right ascension measures a planets longitude but relative to the celestial equator rather than the ecliptic. Declination and right ascension are more related to the latitude and longitude you learned in geography class. We’re can set aside right ascension for the moment though, and focus on declination.
The Missing Ingredient to Chart Interpretation?
If we only use longitude relative to the ecliptic to measure the planets, we’re missing out on the full picture of where a planet is in space. Declination helps us fill out that picture. Since declination is also readily visible in the sky, it’s arguably an important measurement we should take into account.
Some fans of declination claim that it’s the crucial missing component to more accurate chart interpretation. Declination can show connections between planets that aren’t visible using only longitude, whether in the natal chart or by transit.
Declination in History
You may be surprised to hear that astrologers have known about declination since the beginning of our craft, dating at least as far back as Ptolemy, and arguably much further back, based on ancient monuments that seem to have planetary declination built into their construction.
Many astrologers through the years have worked with declination, and one theory about why it fell out of use somewhat in more recent times is that the American Ephemeris stopped including declination tables in their popular ephemeris. But today they make a special ephemeris that includes declination, and you can also find the tables on the Swiss ephemeris for free online, and in any astro software.
Get a full introduction to declination in our Intro to Declination course.
Photo by Warren on Unsplash. Graphic illustration by Simon Avery.
