The Mandylion Rift was large nebula-like space cloud of gas and dust. The Rift was located in the galaxy's Alpha or Beta Quadrant outside the territories of the Federation, Klingon Empire and Tholian Assembly.
History and specifics[]
The Rift's gas shell was hundreds of millions of kilometers wide and produced a colorful kaleidoscope, but obscured a white dwarf star and its system of associated planets. The roiling clouds and gravity well of its star produced enough subspace interference for starships to prefer navigating through it at impulse rather than at warp speeds.
The Rift formed 50 thousand years ago when its star went nova, stripping the atmospheres from its planets and irradiating them. The former star system had at least five planets, including Mandylion V, and one asteroid.
In 2264, a warp 15-capable vessel apparently from the Large Magellanic Cloud was observed going into the Mandylion Rift. The activity was noted by several interstellar civilizations intent on discovering the secrets of the vessel's engineering systems. The starship USS Enterprise traveled through the Rift, where it discovered debris from Andorian and Tholian ships before encountering the mysterious vessel in orbit of Mandylion V. During the investigation, Hounslaw Tanaka piloted the Galileo through the Rift to the fifth planet. (TOS novel: Captain's Peril)