Eberus was a Earth colony, and later a Federation one, founded in 2153. It was considered a peaceful place, since it was far from shipping lanes. Its primary crop was mushroom, used for both medicinal and recreational purposes. (Starship Deimos: "Children of Eberus")
On Stardate 00195.2, the USS Deimos was dispatched to the planet to investigate reports of hostile activity on the colony.