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Naiad is one of the 13 moons of Neptune. Neptune was not discovered until 1989 through studying photos taken by the Voyager 2 probe. Thus, the Voyager Science Team is credited with its discovery. It was the last moon discovered by the probe, which helped scientists find five moons altogether. The last five new moons were discovered in the first decade of the 21st century.
The satellite was given its official name on September 16, 1991. At first the satellite was designated S/1989 N 6. Neptune’s moons are named after figures from mythology that have to do with the Roman god Neptune – or its Greek equivalent Poseidon – or the oceans. The irregular satellites of Neptune are named after the Nereids, which are the daughters of Nereus and Doris, who are Neptune’s attendants in Roman mythology. Naiad was named after a type of nymph in Greek mythology that presided over brooks, streams, wells, springs – all fresh water things.
Naiad is the closest satellite to the planet Neptune. It orbits about 48,230kilometers from the top of the planet’s atmosphere. Naiad is a very small satellite with a diameter of only approximately 58 kilometers. That is about one-sixtieth the size of the Earth’s Moon. Naiad’s mass is so small that it is only 0.00001% of the Moon’s mass. It takes Naiad less than one day – seven hours and six minutes to be precise – to orbit Neptune because of its proximity to its planet. With a decaying orbit, the satellite may crash into Neptune or be ripped apart and become part of one of its planetary rings. This may happen soon.
Naiad is an irregularly shaped satellite, which some have compared to a potato. In one of the pictures Voyager 2 took of it, the moon appears to be elongated because of smearing in the picture. Astronomers believe that the moon is made up of fragments from Neptune’s original satellites, some of which were destroyed when Neptune’s gravity captured Triton as a satellite. They do not think the moon has changed at all geologically since it was formed.
After the Voyager 2 probe passed by Neptune, the planet and its satellites have been studied by many observatories as well as the Hubble Space Telescope and the Keck telescope. Although scientists have been trying to observe Naiad and some of the other smaller irregular moons, scientists still do not know very much about the satellite. This is especially true because Naiad and similar satellites are so small.
Astronomy Cast has an episode on Neptune you will want to see.