To aim the beam to targets on Earth you have to build it in space and be able to maneuver that pretty large Death Star. Probably just a ring instead of a sphere

To aim the beam to targets on Earth you have to build it in space and be able to maneuver that pretty large Death Star. Probably just a ring instead of a sphere. The invisible beam is probably a non starter for movies. If somebody will put this idea on screen they'll find a way to make neutrinos visible.