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 the Derelict Ship was located.
Not much is known about the materials or gases that make up the atmosphere of Calpamos (but is believed to have similar types of materials to the planet Jupiter).
- In Jon Spaihts' original script for Prometheus, titled Alien: Engineers, Calpamos is named "Epsilon".
- The exact origin of the name "Calpamos" is unknown and was likely fan-made. However, as it is used in the Aliens: Colonial Marines Collector's Edition, it is considered canon.