P4X-650 is a planet in the Milky Way 640 light years from Earth, apparently without any indigenous population, and was chosen by Stargate Command for a permanent base of operations. It appears to orbit very near a gas giant and possess at least one moon. (SG1: "Covenant", "Endgame")

P4X-650 is a Tau'ri colony. (SG1: "Relativity")

Alpha Site[]

Following the destruction of the SGC's second Alpha Site by Anubis, the third such base was built into a mountain much like the SGC, with the Stargate placed inside. This Alpha Site also includes a hangar capable of servicing F-302s. (SG1: "Covenant")

Teal'c briefly used the Alpha Site as a base of operations after Earth's Stargate was stolen by agents of The Trust, who began launching attacks on Goa'uld-controlled worlds using symbiote poison. (SG1: "Endgame")

Disruptor satellite 1

A Replicator disruptor satellite arrives through the base's Stargate.

Billionaire Alec Colson was shown this Alpha Site, to impress upon him the importance of maintaining the secrecy of the Stargate Program after he threatened to reveal information about it to the general public. (SG1: "Covenant")

The Replicator version of Samantha Carter was also brought there after contacting the SGC, thus leading Fifth to take a Replicator mothership there. An enlarged Replicator disruptor satellite designed by the Asgard was deployed in orbit of the planet, and successfully destroyed Fifth's ship; however, the Replicator Carter managed to escape. (SG1: "Gemini")

When Earth came under attack from a Wraith super-hive, the International Oversight Advisory dignitaries tried to evacuate to here but failed. Later, Lt. Colonel John Sheppard's team and Major Evan Lorne escaped through the Stargate on the Hive ship to this base seconds before the Hive ship was destroyed by a Nuclear warhead planted on board. (SGA: "Enemy at the Gate")

Known staff[]


Appearances for P4X-650

In chronological order:


  • Strangely, despite the previous practice of abandoning facilities that have been compromised by their enemies, this Alpha Site apparently remained in operation following Replicator Carter's escape. This may be because she was unaware of its location, just that it existed.

Site Navigation[]

v  e
Tau'ri outposts
Earth Air Force Special Operations CommandAnchor research facilityAndrews Air Force BaseAntarctic outpostArea 37-92/NVArea 51Bagram Air BaseBrooks City Air Force BaseClyde Naval BaseEarth DefenseEdwards Air Force BaseEglin Air Force BaseFort BenningFort DetrickFort HuachacaFort KnoxHill Air Force BaseHurlburt FieldInčirlik Air Force BaseKuybyshev AirbaseMarine Corps Recruit Depot Parris IslandMcMurdo Air Force BaseNaval Air Station KeflavikPatrick Air Force BasePeterson Air Force BaseRussian Stargate facilityScott AFBStargate CommandThe PentagonTravis Air Force BaseVandenberg Air Force BaseWest PointWhite Rock Research StationWhiteman Air Force BaseWright-Patterson AFB
Milky Way Alpha Site/P3X-984Alpha Site (II)Alpha Site (III)/P4X-650Beta SiteGamma SiteDelta SiteOmega SiteIcarus BasePhoenix SiteArbellaHawaiiPerseusM4C-862NasyaP1X-774P2S-569P3X-403P4F-221P5C-629Douglas Mclean Memorial Observatory
Pegasus Alpha Site (I)Alpha Site (II)Alpha Site (III)M34-227M44-5Y9Paradise world
Mobile AtlantisDestiny