Ho do I move an object on an elliptical path?

I need to move earth gameobject around sun in a ellipse path.

Please help.

Sorry guys,got answer.

Based on ellipse equation we can ,make an object rotate in a elliptical path. The code I used is

var a : int;
var b : int;
var x: int;

var y : int;
var alpha : int;
var X : int;
var Y : int;

function Update () {
    alpha += 10 ;
    X = x + (a * Mathf.Cos(alpha*.005));
    Y= y + (b * Mathf.Sin(alpha*.005));
    this.gameObject.transform.position = Vector3(X,0,Y);

Look here to determine the values a, b, x, y, alpha

mathematics - Moving an object in a circular path - Game Development Stack Exchange