Can I get the Tangent(as Vector3) of a sphere at the hit point with raycast?

Hello everyone!
I have to plot models on a sphere by simply draging prefabs and plotting them on a sphere.
The drag is working fine, I need to raycast to know the point where the object will be plotted.
But I need the tangent at the hit point so that the plotted object sit well on the sphere(the y of the object will be the same direction as the tangent and not up in world space)
Is there method that gets that tangent or I have to calculate it?
Any possible solution will help:)

Here is an example, only the raycast part you need, so implement this into your script. You can test this by creating a large sphere, then creating a cube a few meters above the sphere, and attaching this script to the cube. The cube or rectangle, whatever object you have the script attached to, will attach to whatever its down facing ray hits. You can of course modify this how you wish. Hope this helps resolve your issue.

function Update()

{

var hit : RaycastHit;

var down = transform.TransformDirection(Vector3.down);

if(Physics.Raycast(transform.position, down, hit))

{

	transform.position = hit.point + hit.normal;

	transform.rotation = Quaternion.FromToRotation(Vector3.up, hit.normal);

}

}