Laomedeia, a moon of Neptune
14,645,691 miles
26 miles
Laomedeia is one of Neptune's fourteen moons. It has a diameter of 42 kilometres (26 miles). It orbits at an average distance of 23.6 million kilometres (14.6 million miles) from Neptune, taking 3,168 Earth days to complete a full journey around the planet. It is the twelfth most distant moon from Neptune.
Laomedeia was discovered on 13th August 2002 by teams of astronomers led by Matthew Holman and John Kavelaars. Their discovery was as part of a project to search for distant moons of Neptune. In the summer of 2001, they obtained images of areas around Neptune where moons may be located using the Cerro Tololo Inter-American Observatory and Canada-France-Hawaii Telescope. They detected six potential objects, and repeated the search again in August 2002 and August 2003, to confirm their findings. Five of those six new moons were seen again, including the moon that is now known as Laomedeia. The other moons discovered through this method are Halimede, Sao, Psamathe and Neso.
Laomedeia is classed as an irregular prograde moon. An irregular moon usually refers to a moon that has been captured by a planet's gravity rather than one which formed around it. Laomedeia is also an irregular shape. A prograde moon is one that orbits in the same direction as its host planet's rotation. It's likely that Laomedeia was originally an asteroid or an object that formed in the Kuiper Belt.
In Greek mythology, Laomedeia is one of the Nereids, one of the 50 daughters of Nereus and Doris. The Nereids are kind and helpful sea nymphs. She is described as "leader of the folk", although it's not clear what folk she is leading!
The moon's name was announced on 3rd February 2007. Its provisional name was S/2002 N 3. It may also be referred to as Neptune XII.