How do I explode multiple clones out of an object?

How do I explode multiple clones out of an object?

I have an asteroid which when killed I want to create multiple smaller clones of itself.

for (int i = 0; i < 3; i++) {
    Transform clone = Instantiate(transform, transform.position, Quaternion.identity) as Transform;

    Vector3 scale = transform.localScale;
    scale.x /= 2;
    scale.y /= 2;
    scale.z /= 2;
    clone.localScale = scale;
}

But because they are rigid bodies they just fly out from each other. How can I instantiate them so the explode out in a uniform pattern?

I think you should not instantiate them all at the exact same location as they are rigid bodies
add a random Vector3 to their position for that

then you should add a force to get them to move away from the original transform.position of the first asteroid