Function classifyMotion

classifyMotion(body: CelestialBody, jd: number): MotionState
Classify the motion state of a body at a given time.
Parameters
- body: CelestialBody
  Celestial body
- jd: number
  Julian Date
Returns MotionState
Motion state
Remarks
- Direct: Moving forward (positive longitude speed)
- Retrograde: Moving backward (negative longitude speed)
- Stationary-retrograde: About to turn retrograde (speed ≈ 0, decreasing)
- Stationary-direct: About to turn direct (speed ≈ 0, increasing)
- Defined in transits/retrograde-transits.ts:58