Check the entry point of a ship in planet's orbit and tell if movement is in rotation direction (2D)

 /*@iubisoft Basically you have to calculate the angular velocity of the planet and the angular velocity of the ship in relation to the planet. Here's my test script which I used to calculate it. It's signless. I can't think of a way to resolve flying in the opposite direction at the correct velocity this tired so I'll leave that up to you (maybe tomorrow :P):*/
 
 using UnityEngine;
 using System.Collections;
 
 public class ResolveSpeedenfp : MonoBehaviour {
     public PlanetScript planet;    // Planet is a simple script which rotates a gameObject by speed * Time.deltaTime
     public Rigidbody2D ship;        // Ship is a controllable rigidbody.
 
     void Start(){
         // This script was attached to a trigger gameObject with a parent gameObject holding the planet component.
         planet = transform.root.GetComponent<PlanetScript> ();
     }
     public void OnTriggerEnter2D(Collider2D col){
         Debug.Log ("Collision enter");
         // I was having some difficulty with getting this function to work, you might as well ignore all this :P
         try{
             this.ship = col.transform.gameObject.GetComponent<Rigidbody2D>();
         }catch{
 
         }
     }
     Vector2 enfp;    // Extrapolated next frame position.
     Vector2    prp;    // Position in reference to planet.
 
     // Update is called once per frame
     void Update () {
         if (ship != null) {
             // Additional gravity for testing purposes
             //ship.AddForce((planet.transform.position - ship.transform.position).normalized * 2f * Time.deltaTime);
 
             // This vector "extends" from the planet to the ship.
             prp = ship.transform.position - planet.transform.position;
             // This vector is the same, except we've added one frame's movement to it, extrapolated.
             enfp = prp + (ship.velocity * Time.deltaTime);
 
             // The angle between current position and next frame position should be a sufficient approximation of angular velocity.
             float angVship = Vector2.Angle (prp.normalized, enfp.normalized);
 
             // Angular velocity of the planet.
             float angV = planet.speed * Time.deltaTime;
 
             // The output of this debug log was quite convincing when the speed of the ship began to match the speed of the surface of the planet.
             Debug.Log (angV.ToString () + "   " + angVship.ToString ());
         } else {
             enfp = Vector2.zero;
             prp = enfp;
         }
     }
 }
 
 
 //Angular velocity is usually expressed in radians, but I'm using degrees/frame. (float angV = planet.speed * Time.deltaTime;)