Thalassa (moon)

Thalassa is one of the moons of Neptune, discovered in 1989 by the Voyager 2 spacecraft during its flyby of the planet. It is the third-largest of Neptune's known moons and is part of a group of moons that are known as the "inner moons," which also includes Naiad, Despina, and Galatea. Thalassa has a somewhat irregular shape and is relatively small, with a diameter of about 80 kilometers (approximately 50 miles).