From Star Trek Online Wiki
Being identical to the N'Vak System, it is known as a Space War Zone in which players must complete certain objectives. Both systems feature a large Borg presence with a scenery containing a small cracked planet and Borg remains.
 System description
Ker'rat is a dim orange star with a jungle world located at the edge of its habitation zone. During the Borg incursion into the Beta Quadrant, the Borg cannibalized the planet's moon to create repair facilities for their forces.