[Closed] Circle surrounding sphere by camera viewport distance?

Hi,

My Setup:
[ul]
[li]Sphere at 0 0 0 radius 100[/li][li]Circle at 0 0 0 radius 101 with lock at to:[/li][li]Camera[/li][/ul]My Target:
When my camera drives to the sphere, my circle radius should go bigger and surrounding the Sphere. (Attachment)

My Question;
How to create the two Lines between Camera and Sphere Surface?

Thanks for your Help,
Oli