The 20 Parsec Limit was a limit confining the establishment of extrasolar colonies to no more than twenty parsecs from Earth.
History
The 20 Parsec Limit was brought into force in 2113 following the loss of the Far Spinward Colonies and the Trailward–bound colony ships Affiance and USCSS Covenant between 2110 and 2112. Despite the 20 Parsec Limit being in force, locales still operated outside of it, such as Hyperdyne Systems' mining colonies in the Hyades Cluster and the United States Colonial Marine Corps' Tanburro Station listening post in the 78 Nu Ceti System. Although the purview of the United Americas allegedly did not exceed the Limit, an exception was made during the Hyades Revolts in 2156.