Calpamos possesses rings, much like the planet Saturn; these rings are thought to be the remains of a disintegrated moon that was broken apart by the gravitational shift induced when Acheron (LV-426) was captured by Calpamos' orbit, some 40 million years ago. The planet's coloration has a somewhat mixed, in some parts is light brown and in others a darker brown. Its most notable feature is its three small moons, including Acheron, where a derelict Engineer ship was located, and LV-223, which was the site of a major Engineer facility.
- In Jon Spaihts' original script for Prometheus, titled Alien: Engineers, Calpamos is named "Epsilon".
- The exact origin of the name "Calpamos" is unknown, but is thought to have begun as a fan-made term, before later being adopted in supplemental materials for the Aliens: Colonial Marines Collector's Edition. It went on to become a part of official canon when it appeared in the comic series Fire and Stone and the novel Alien: River of Pain.
- Alien/novel/comic (First Appearance)
- Aliens: Colonial Marines (video game)
- Prometheus: Fire and Stone
- Aliens: Fire and Stone
- Aliens: Field Report (mentioned only)