This most recent update reorganizes the UI in what I hope is a more sensible fashion.  I also added a Sun feature and the ability to rotate the camera view about the scene.  The camera distance remains fixed at 100 units, but by holding the left mouse button and dragging, one can rotate around the central planetary object.  The mouse scroll wheel still permits you to zoom in and out.

Feedback is always appreciated as I continue to develop this and other tools to use in my astronomy and game dev classes.