Eridon Prime was a Federation planet in the Nimbus sector, located near the border to the Romulan Star Empire and in general vicinity of the Beta Lankal system. During the Borg invasion of 2376, the space around the planet was the site of several engagements. (ST video game: Armada)
Eridon Prime was in the same sector as Starbase 612. In July 2376, the Borg Collective ransacked the starbase and its fleet. When the USS Enterprise-E arrived to render aid, Starfleet detected a rich dilithium moon in Eridon Prime's vicinity. (ST video game: Armada mission: "Dark Omens")
Later on, Locutus led a squadron of Borg ships into the area and the Collective constructed a Borg Nexus in the orbit of Eridon Prime. Their base came under attack from Romulan ships until the Borg went on the offensive and destroyed or assimilated all Romulan structures and ships in the sector between Eridon Prime and Beta Lankal. (ST video game: Armada mission: "Assimilation")
The entire planet was covered with a dense atmosphere. Eridon's cyan atmosphere was layered with blue bands. From a distance, Eridon Prime appeared darker and bluish. In the southern hemisphere, the atmosphere was tinted green.
- It is unclear whether the planet is a gas giant or habitable. Constructing a starbase above its north pole increases the recruitment of crew, suggesting it could be the site of a colony.