Geocentric
Measuring from the centre of the Earth — the default setting, and the one that does not need to know where the observer is standing.
Measuring from the centre of the Earth — the default setting, and the one that does not need to know where the observer is standing.
No planet ever reverses. Retrograde motion is what overtaking looks like from a moving platform, and it is absent when positions are measured from the Sun.
The point a direction is measured from, a question that sits underneath every position, and the one the coordinate origin setting answers.