class MOON{
  
  //Initalize variables
  
  float r, Theta, Omega, v;
  /* where:
  r is the radius of the orbit
  Theta is the angular displacement
  Omega is the angular velocity
  v is velocity of the orbit
  */
  
  //Attributes
  MOON(boolean rightSpin){
    
    //works out the coordinates in polar form
    r = dist(width/2,height/2,mouseX,mouseY);
    Theta = atan((mouseY-height/2)/(mouseX-width/2));
    
    //find Omega, the angular velocity
    v = sqrt((G*M)/r);
    Omega = v/sqrt(pow(r,2));
    
    //define the direction of the orbit
    if (rightSpin==false){
      Omega*=-1;
    }
  }
  
  //Methods
  
  void display(){
    stroke(0);
    fill(0,255,0);
    ellipse(r*cos(Theta),r*sin(Theta),20,20);
    Theta+=Omega/frameRate;
  }
  
}