rotateAround not working correctly

I’m trying to rotate one sphere around another sphere, like a planet around a sun. No matter what I do tho, the planet object only rotates around it’s axis and doesn’t move. This is the code I’m using:

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Update() {
        transform.RotateAround(Vector3.zero, Vector3.up, 20 * Time.deltaTime);
    }
}

I’ve tried to set the first Vector3 to the transform.position of my Sun object, but no matter what I do, it just sits in one place and rotates on its own axis but never actually moves. Doesn’t matter what I put in there, it seems.

What am I doing wrong?

Make sure you have offset your planet.

The code you have written will rotate around world.zero, but if your planet is sitting at world zero, there is no rotation distance.