Galactic quadrant (Star Trek)

In the television series Star Trek and its spin-offs, a galactic quadrant is an area of the Milky Way Galaxy. In the original Star Trek, it referred to an area interchangeable with a sector. However, in the various spin-off series and movies beginning with Star Trek: The Next Generation, it refers to a system of four galactic quadrants, designated by the Greek letters Alpha, Beta, Gamma, and Delta.

The original usage of quadrant occurs in episodes such as "The Deadly Years" and "The Squire of Gothos", where numbered quadrants (448 and 904) are given. In other episodes it appears to refer to an entire quarter of the galaxy. The season 3 Star Trek: The Next Generation Writers' Technical Manual asserts that there are four quadrants in each sector (which seem to vary in size).

The exact quadrant borders are not clearly established in the series canon. Episodes often contradict each other. Art staff explanations also contradict each other.

The Star Trek: The Next Generation episode "The Price" (1988) introduced the concept of four quadrants of the galaxy, named the Alpha, Beta, Gamma, and Delta quadrants, respectively.

Star Trek VI: The Undiscovered Country implies that the Alpha/Beta border runs through, or is relatively close to, Federation space. The Star Trek Encyclopedia attributes this decision to a desire to rationalize a line in Star Trek II: The Wrath of Khan, in which James T. Kirk claimed that the Enterprise was the only ship in a Quadrant. Most of the maps produced by the art staff for the series (both on-screen and published) show that the Solar system is roughly in the center of the Alpha Quadrant, but some of the maps show that the Solar system is at the edge of the Alpha and Beta Quadrants.

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