LV-426 (Acheron) is a satellite orbiting the ringed planet Calpamos in the binary star system Zeta Reticuli, 39 light-years from Sol.

It is notable for being home to a colony of Xenomorphs, one of the most dangerous parasitic lifeforms in our galaxy. However, they must rely on the chance visit of other alien species like humans or Space Jockeys (now known as Mala'kak). No native species are found here. The Xenomorph eggs are located in a large room in or beneath a crashed Mala'kak derelict space vessel.

Characteristics of LV-426 (Acheron)Edit

Although this satellite is only 1200 kilometers in diameter, the gravity of LV-426 (Acheron) is about .86 of Earth's, which means it has a density 49,486 kg/l, higher than any element currently known. It also appears to have a magnetic field since humans were able to terraform it and create a stable atmosphere. There is a temperature difference (though only slight) which is enough to create the almost constant gales here. Calpamos and its 3 moons, are only just outside Zeta 2's habitable zone. LV-426 formed from a disc of gas and dust that orbited around Calpamos when this whole system was young, a lot of this material clumped together to form the 3 satellites of which LV-426 is the middle one. The inner moon is called Rosto, similar in size and composition to Europa that orbits our Jupiter. The outer moon is called Varda and is an innert lump of rock very much comparable to Earth's moon. Varda barely has an atmosphere and there is no detectable water. The ring system surrounding Calpamos may have been formed from the collision of 2 smaller moons several million years ago, or most likely the residue left over from the original disc of dust and gas that never condensed together.

The atmosphere of LV 426, is described by Ash as 'almost primordial', and consists mostly of nitrogen, but also methane, carbon dioxide, ammonia and smaller amounts of other trace elements. The temperature is deep cold, well below the line, circa - 111 °C.

History of LV-426 (Acheron)Edit

LV-426 was the location of the supposed first contact between humanity and the Xenomorph species, and the second evidence of the Mala'ka civilization (the first being on LV-223), when a dead specimen was found in the derelict spaceship on LV-426 (Acheron).

It was later terraformed by humans. A colony (Hadley's Hope) was established there and parts of the satellite were given names, such as the Ilium Range, and the Gorgonia Rocks. Under orders from Carter Burke, the colonists investigated the Xenomorph eggs and a large number of colonists were 'facehugged' so that the species could be studied. Several dead Xenomorph larvae were kept preserved, and two live ones were removed before embryo implantation, at the cost of the lives of the hosts. However, the humans who had embryos inside them released chestbursters which grew up and (possibly) slaughtered humans for food, and definitely captured them and coccooned them in a hive, built in sub-level 3 of the Hadley's Hope atmospheric processor. Hundreds of dead bodies could be seen within the hive, and all the trackers (which all colonists had) were located there. A special larva grew into a Queen and started producing eggs, which then produced 2 types of facehugger, (Regular & Queen) which implanted embryos into captured humans. The remaining humans barricaded themselves into the colony complex and fought with small arms and the colony's seismic survey charges, but the Aliens used the air vents to flank them and killed or captured them all, literally tearing some of them to pieces.

A short while after this, a Colonial Marines squad, including Lieutenant Ellen Ripley, arrived on LV-426 to investigate the loss of communication. After many battles with the Xenomorphs, Ripley destroyed the creatures hive in a nuclear explosion from the terraforming plant's power source. Ripley, a young girl she had adopted (called "Newt"), a Marine, and an android ("Bishop") managed to settle themselves into 3 of the 20 cryotubes on board the USS Sulaco. Unknown to them, a Queen and a regular larva had managed to get aboard.

However, back on LV-426 it would soon be discovered that the nuclear explosion had actually failed to either eliminate the entirety of Hadley's Hope nor clear out the Xenomorph infestation and a second marine expedition to the planet would prove far more dangerous than Ripley's team had encountered.


  • LV-426 would go on to inspire another famous planet infested with parasitic lifeforms - SR388, according to the game series' creator(s) who stated that it was largely inspired by the Alien franchise.
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