A dark and distant planetoid that orbits the Sun within the Kuiper Belt, beyond the orbit of Pluto. Salacia is less than half the diameter of Pluto, and its orbital path around the Sun is somewhat less eccentric. This body - which is almost certainly a dwarf planet, though not yet formally classified as such - takes its name from the wife of Neptune in Roman mythology.
Salacia is notable for its extremely low albedo: it reflects less sunlight than any comparable object beyond the orbit of Neptune. Its physical structure is not understood in detail, but it is likely composed of a rocky core surrounded by a thick mantle of ices.
Salacia does not pursue its distant orbit alone, but possesses a single known satellite. Known as Actaea,* this object follows a nearly circular orbit around Salacia at a distance of some 5,600km. The diameter of this moon is about 300km, or as much as a third that of Salacia, though it is far less massive than its parent planetoid.
* In mythology, Actaea was a nereid, sister to the sea-god's consort, and thus appropriate for Salacia's moon (though the name Actaea comes from the Greek tradition, in which the equivalent of Roman Salacia would be Amphitrite, the wife of the sea-god Poseidon).