- For the novel of the same name, see Belle Terre (novel).
Belle Terre is the fourth planet in the Occult system, in Cluster Z-80 of the Sagittarian Stellar Group, six months distant from the United Federation of Planets in the 23rd century. A lush, Class-M world, Belle Terre (French for "Beautiful Earth") nonetheless remained uninhabited until the 2270s when sixty-thousand or so Federation citizens set out on the Belle Terre Colonial Expedition to settle the planet. (TOS - New Earth novel: Wagon Train to the Stars)
The planet had nine moons, including a tectonically active satellite nicknamed the "Quake Moon", which was discovered to have vast quantities of the rare substance quasar olivium. Three weeks after the colonists arrived at Belle Terre, pressure within the unstable Quake Moon built to the brink of a catastrophic eruption. The planet would have been rendered uninhabitable had the USS Enterprise not intervened. It led the colony ships in using tractor beams to crash "the Needle" (a small moon of the twelfth planet in the system, a gas giant) into the Quake Moon, alleviating the pressure. Even so, the Quake Moon's eruption bombarded Belle Terre's largest continent with radiation, and released the olivium into the atmosphere, causing severe weather conditions across the planet. (TOS - New Earth novel: Belle Terre)