The Great Rift is an area of sparse star count between the Sagittarius and Orion Arms of the Milky Way Galaxy. It was little explored by the Federation until the dispatch of the U.S.S. Marignano in 2369.
Planets near this region include 22 Ophiuchi, 127 Scorpii, 334 Scorpii, 1440 Ophiuchi B V, 1616 Ophiuchi VI, 1865 Serpens, B Hydri, Beta Ophiuchi VI, and Chi Scorpii. (novel: Star Trek: The Next Generation: Intellivore)