Galactic barrier
The area in space known as the "galactic barrier" is an energy field composed of negative energy surrounding the rim of the Milky Way Galaxy.
At a distance, this barrier is invisible to both the naked eye and visual recording equipment, though at close range it appears as a purple-to-pink-colored glow.
No form of transmission is currently known to be capable of penetrating the barrier, and warp travel through the barrier is known to cause extreme sensory distortions.
The barrier has been encountered on several occasions by Earth and Starfleet vessels.
According to Starfleet Intelligence, the barrier is depicted as a toroidal shape (pictured right) that surrounds the entire galactic disc.
It is estimated to be thickest at the rim, perhaps 10,000 light years wide, starting out from a distance of 40,000 light years from the center of the galaxy.
Known Encounters
The first documented encounter happened in 2065, involving the Earth vessel SS Valiant. The ship was swept into the barrier by a magnetic storm, and subsequent events resulted in the destruction of the
Valiant and the loss of all hands. This information was only made available to Starfleet by way of scans and records 200 years later.
In 2265, the USS Enterprise found the Valiant's "disaster recorder," the ship's "black box," as it were. When they retraced the ship's path to solve the mystery of its destruction, the Enterprise was unable
to detect the galactic barrier, and were almost destroyed in the same fashion the Valiant had been.
In 2268, Kelvans from the Andromeda Galaxy entered the Milky Way Galaxy through the barrier. Their advanced multi-generational ships were damaged by the barrier, and were subsequently destroyed. The survivors of one ship required a new vessel for the journey home, and so hijacked the USS Enterprise, refitting it to survive the barrier and the intergalactic journey. Presumably, due to improvements in sensor technology, the Enterprise's sensors registered the barrier as negative energy, but of such magnitude that all instruments were off
the dials.
Later that same year, the Enterprise left the Milky Way Galaxy when a Federation engineer was driven mad by the sight of an alien species known as the Medusan.
Becoming trapped inside the barrier, no sensor data or reference points were available to aid in escaping the space. Fortunately, that same Medusan was able to lead the flagship to safety.
Inside the Barrier
Entering the barrier is considered "extremely hazardous." Shields cannot currently block all the energies of the barrier, and leakage of these energies is sufficient to heat up a hull to over 2,000 degrees, as well as damage several systems.
Additionally, it has been documented that severe electric shocks occur throughout the ship in question, which can be strong enough to cause brain damage and death. In rare instances, these electric shocks can also cause a subject to develop psychic abilities.
