As far as I can tell, the PG you are linking is just moving the position of the camera in a straight line towards the target point. This will end up in the right place, but the motion won’t feel correct. I think what you really want to be doing is staying the same distance from the sphere, but changing the alpha value of the ArcRotateCamera so that it orbits the sphere. I tried to put together a simple diagram for this:
What you have right now is the red line, but what you want is closer to the blue line; a path that travels along an imaginary circle centered at the origin, rather than a straight line.
In order to do this, what you’ll need to do is calculate the target alpha value (and maybe beta value, too), and then animate those properties, rather than animating the position property. If you hold the radius constant, this will create the desired spinning effect. (At least, I think this is what you are going for.) In order to calculate the correct values, you will need to do a bit of trigonometry…this forum thread might help you get started.
Let me know if you’re able to get that working 