Neptune Fast Facts
Neptune is the eighth furthest planet from the sun, and is four times the diameter of Earth.
Neptune was discovered on September 23, 1846 by Johann Galle, based on mathematical predictions of its location by Urbain J.J. Levirrier. The discovery of Neptune is credited to John C. Adams, an astronomer and mathematician, and Urbain J.J. Levirrier, a mathematician.
Origin of the Name
Neptune was named by Johann Galle after the sea god of Roman mythology.
Neptune is believed to be made up of hydrogen, helium, water and silicates. The planet has a central core of rock and ice surrounded by heavily compressed gases.
Neptune has four rings that are possibly made up of dust particles. The outer ring, which is unlike any other ring in the solar system, has three curved pieces that are thicker and brighter than the rest of the ring.
The 13 moons of Neptune are named Triton, Nereid, Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, Halimede, Psamathe, Sao, Laomedeia and Neso. Triton is an unusual moon in the fact that it orbits opposite the planet’s rotation.
Neptune circles the sun every 165 years; a day on Neptune lasts about 16 hours and 7 minutes.