The Galactic Barrier is an energy field composed of exotic energy surrounding the rim of the Milky Way Galaxy. Invisible to both the naked eye and visual recording equipment at a distance, at close range the barrier shines with a purple- to pink-colored glow. No form of transmission is known to be capable of penetrating the barrier. Warp travel through the barrier caused extreme sensory distortions. The barrier has been encountered on several occasions by Earth and Starfleet vessels.