What is the easiest way to measure a distance at an intersecting point at the surface of a sphere?

Often I need to measure the projecting distance of a cylinder (pipe) through a sphere (or cone).
Or to make this question easier, how do I measure where a line intersects the surface of a sphere in a 3D model. The true length would best be seen in the front elevation view.

To this point I have been using the subtract solid command to make it easier to snap to the surface of the intersection point but I am sure, there must be an easier way to measure this distance or place a dimension (in order to get a distance).

Thanks for your help.