Although it was initially spotted by H. Reitsema, W. Hubbard, L. Lebofsky, and D. Tholen through ground-based telescopes in 1981, Larissa was officially discovered in July 1989 by the Voyager 2 science team.
Larissa is another of the small moons found near Neptune's faint ring system in 1989. Like Despina and Galatea, Larissa is irregularly shaped and heavily cratered.
Larissa's orbit is mostly circular, but it is slowly spiraling inward and may eventually impact Neptune's atmosphere, or the gas giant's tidal forces may break Larissa apart to form a planetary ring. The moon orbits Neptune in about 13 hours and 20 minutes.
How Larissa Got its Name
Larissa was a nymph from Greek mythology. The moon was originally designated S/1989 N 2.