LV-426, or commonly known as Acheron, is a moon orbiting the ringed planet Calpamos in the binary star system Zeta Reticuli, 37 light years from Sol.
It is notable for being home to a colony of Xenomorphs, one of the most dangerous parasite lifeforms in the universe. The Xenomorph eggs are located in a large room in or beneath a crashed Space Jockey derelict ship.
The Ilium Range is a mountain range on the Acheron moon where the USCSS Nostromo discovered The Derelict in 2122.
Terrain & Climate
Acheron has a 1200 km diameter at its quadrant points QBR 157 052 and has a molten lava base. The atmosphere on Acheron is comprised of 10% Argon, 85% Nitrogen and 5% Neon and maintains a gravitational field equivalent to 0.86 of that on Earth. In 2122 the Weyland-Yutani commercial hauler USCSS Nostromo discovered the The Derelict here. The human colony Hadley's Hope was founded on LV-426 sometime in the twenty-second century, which began terraforming operations which were planned to last decades. By the late 2170's the terraforming project resulted in Acheron possessing a weak but breathable atmosphere for humans, though plant and animal life had not yet been introduced.
The first notable incident to occur on the planetoid was when the commercial tow freighter Nostromo touched down to investigate a mysterious signal on the planetoid per company protocol. They discovered the Derelict, and one of the three crew members who entered (Kane) was impregnated by a facehugger. The Nostromo soon lifted off again, but the creature implanted an embryo in Kane which birthed from his chest in space, leading to the events which would later occur on the planetoid.
Approximately thirty-seven years after the USCSS Nostromo made contact with LV-426, the Weyland-Yutani Corporation established the colony, Hadley's Hope, on LV-426, using an atmospheric processor to make the planet's atmosphere breathable.
Another twenty years later, a family sent to investigate a set of coordinates on company orders, discovered the Derelict, apparently untouched since the Nostromo incident fifty-seven years earlier. A facehugger alien attached itself to the father when he attempted to explore the Derelict. 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 larva 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 atmosphere 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"), Corporal Dwayne Hicks, and an android ("Bishop") managed to settle themselves into 3 of the 20 cryotubes on board the Sulaco. Unknown to them, 1 Queen, and 1 Regular facehugger had managed to get aboard.
However, during the second USMC squad's investigation to LV-426 reveals that the Xenomorphs had in fact survived the nuclear explosion from the atmosphere processor.