Heliocentric
Heliocentric measures every direction from the centre of the Sun.
This is not an adjustment to the Earth-based settings. It is a different vantage point altogether, and the first thing it changes is not a position — it is the guest list.
The chart's contents change
Select Heliocentric and the applications rebuild the list of available bodies, because three of the usual ones stop making sense and one new one appears.
| Body | Geocentric | Heliocentric |
|---|---|---|
| The Sun | yes | no |
| The Earth | no | yes |
| The Moon | yes | no |
| The lunar nodes and apogee | yes | no |
| Mercury to Pluto | yes | yes |
The Sun goes. You are standing on it. A body has no direction from its own centre, so a heliocentric solar position is not a number that exists.
The Earth arrives. From the Sun, the Earth is simply the third planet out, and it has a position like any other. It is always exactly opposite where the Sun appears from here — the same line, read from the other end.
The Moon goes, and the nodes with it. The Moon orbits the Earth, not the Sun. Its heliocentric position would be the Earth's position with a small monthly wobble on it, which describes nothing anyone wants. The lunar nodes and apogee are features of the Moon's orbit around the Earth and are meaningless without it.
This is why changing the origin can empty a selection you had carefully made. The applications are not discarding your choices; the bodies you had chosen do not exist in the frame you have moved to.
What the positions mean
A heliocentric position is a planet's actual place in its orbit.
That is a stronger statement than it sounds. Geocentric positions are compounded of two motions — the planet's own orbit and the Earth's — mixed together by the fact that the observer is riding on one of them. Heliocentric positions have the Earth's motion removed, because the Earth is no longer where you are standing.
The consequences are visible immediately:
- Motion is smooth and steady. Each planet moves round its orbit at a rate that varies only gently. There are no stops, no reversals, no loops.
- Speeds are simply orbital periods. Mercury goes round in 88 days, Neptune in 165 years, and that is all there is to it.
- The bodies stay much closer to the ecliptic. Seen from the Sun, a planet's distance from the ecliptic plane is just its orbital inclination — small and slowly varying — rather than the larger swings that the Earth's own motion introduces.
Nothing is retrograde here
The most striking consequence gets its own page next, but it is worth stating in place: no planet is ever retrograde in a heliocentric frame.
The applications enforce this rather than merely allowing it: no heliocentric body is ever reported as retrograde, and studies whose entire subject is retrograde motion remove the Heliocentric option from the dropdown altogether, on the explicit grounds that what they are looking for is a geocentric phenomenon.
What it is for
Heliocentric work is a minority practice and this site takes no view on its interpretation. What can be said is what it shows:
Real orbital relationships. When two planets are genuinely on the same side of the Sun, or genuinely opposite, the heliocentric frame says so and the geocentric frame does not.
Cycles without the Earth's interference. A heliocentric aspect between two outer planets is a clean statement about their orbits. The geocentric version of the same aspect is smeared by the Earth's annual motion and the retrograde loops that come with it.
A check on what is real. If a pattern appears geocentrically and vanishes heliocentrically, it is telling you something about the vantage point rather than about the planets — and that is worth knowing either way.
What comes next
The single clearest example of a geocentric appearance that is not a fact about the planet.