Thedus was a mining world located in the Epsilon Reticuli System approximately 59 light years Trailward from Earth.[1]


Initially mistaken for a small gas giant, Thedus was in fact a terrestrial planet loaded with heavy metal veins that were quickly and heavily exploited by the Weyland-Yutani Corporation for more than a century, leaving much of the planet's surface riven with huge gouges and deep canyon–like trenches. Alongside Anchorpoint Station, Thedus was a transit point for exported materials being moved from the Frontier to the Outer Veil and Core Systems.[2]

During the Torin Prime uprising in 2106, J'har advisors fomented a labor dispute on Thedus to disrupt the United Americas' military supply lines to Torin Prime; this dispute lasted four months.[3]

In 2109, Thedus suffered a severe environmental accident that rendered parts of the planet uninhabitable for decades, followed by a miners' revolt over poor living conditions. The incident forced the United Americas to deploy the United Americas Outer Rim Defense troop carrier UAS Archangel on a peacekeeping mission to Thedus.[2] On December 25th, 2109,[4] for unknown, classified reasons, the Archangel crashed into an atmospheric processor, destroying the site and killing 15,293[4] civilians and marines.[2] The incident vetoed the UAORD expansion initiative and led to its restructuring into the Outer Rim Defense Fleet.[5]

In 2121, Thedus was the last port of call for the commercial towing vehicle USCSS Nostromo before the ship went missing alongside the Tesotek 2100-B refinery it was towing in 2122.[2] As of the 2180s, most of the historic damage effected on Thedus' surface had been repaired via terraforming.[2]

Climate and terrain[]

Though cold, Thedus' atmosphere was breathable for humans, with a mean temperature of 8°C. Thedus was mainly terrestrial, with the planet containing various heavy metal deposits.[2]


Thedus' key resources included yttrium, niobium, helium-3, and other rare earth metals.[2]


As of 2183, Thedus' human population stood at 2,000,000.[2]

Points of interest[]

The United States Colonial Marine Corps Eridani Marine Space Force garrison was stationed on Thedus.[6] The Weyland–Yutani Corporation maintained one of its main offices on Thedus.[7]

Behind the scenes[]

In Aliens: Colonial Marines Technical Manual, Thedus is misspelled Thetis.[8]