Naiad (moon)

Naiad is a small moon that orbits the planet Neptune. It is known officially as Neptune III and was discovered in 1989, earning it the temporary name S/1989 N 6. The moon is named after the naiads, water spirits from Greek legend.

As the innermost moon of Neptune, Naiad circles very close to the planet, only about 48,224 kilometers from Neptune's center. This close distance means Naiad completes its orbit faster than Neptune rotates on its axis. Because of this, the gravitational pull between Naiad and Neptune causes the moon's orbit to slowly get closer to the planet over time.

Scientists believe that in the future, Naiad will either crash into Neptune's atmosphere or break apart and form a new ring around the planet. Its closeness to Neptune makes it a fascinating object to study, helping us understand more about the complex system of moons that surround this distant world.

History

Naiad was found before mid-September 1989 using pictures from the Voyager 2 probe. It was the last moon discovered during the space mission and was called S/1989 N 6. The discovery was shared on 29 September 1989. The moon was named Naiad on 16 September 1991.

Physical characteristics

Naiad has an irregular shape. Scientists believe it is made up of pieces that came together again after being broken apart. This happened when Triton was captured by Neptune and its path around the planet became very uneven.

Orbit

Naiad moves around Neptune in a special pattern with another moon called Thalassa. Every time Naiad goes around Neptune, it passes Thalassa twice from above and twice from below. This pattern repeats about every 21 and a half days on Earth. Even though the moons are close to each other, this pattern helps keep their paths safe and separate.

Exploration

Since the Voyager 2 flyby, scientists have studied Neptune and its moons using telescopes on Earth and the Hubble Space Telescope. In 2002–03, the Keck telescope looked at Neptune and found the four largest inner moons, but Naiad was not seen then. Later, in October 2013, the SETI Institute found Naiad in old pictures from the Hubble Space Telescope taken in 2004. Naiad was found far from where it was expected, showing that earlier guesses about its position were wrong.