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 disappears the moment you step off.
The point a direction is measured from — the question hiding underneath every position, and the one the Coord. Origin dropdown answers.