*In 1846, English astronomer John C. Adams and Frencnman Urbain Le Verrier are credited with discovering the planet Neptune. It is also the first planet to be discovered through mathematical prediction after it was noticed that something seemed to be affecting the orbit of Uranus.
*The planet Neptune is named after the Roman god of the sea. In keeping with his aquatic nature, Neptune has 13 known moons named after various water dwelling characters from Greek and Roman mythology. The Nereids, or sea nymphs feature prominently in this line up (Nereid, Galatea, Halimede, Sao, Laomedeia, Psamathe, Neso). Its other moons are Naiad, Thalassa, Despina, Larisaa, Proteus and Triton.
*Neptune (49,532km wide) is the fourth largest planet in the solar system and like Uranus is called an “ice-giant.” The planet’s core is believed to be comprised of rock and ice covered with a thick layer of liquid hydrogen, while its atmosphere is composed of 74% hydrogen, 25% helium and 1% methane. As with Uranus, it has a bluish color because of methane in its atmosphere.
*One day on Neptune lasts 16 hours, but the planet’s orbit around the sun takes 164.83 Earth Years. Its vast distance from the Sun means Neptune is one of our solar system’s coldest planets with an average temperature of just -200c.
*Neptune has only been passed by the Voyager 2 spacecraft, which flew by in 1989, twelve years after leaving Earth. The Nasa spacecraft flew about 4,950 kilometers above the planet’s north pole.
*Neptune is not easily visible through binoculars, and would require at least a 4 inch reflector telescope or a 60mm refractor with a magnification power of at least x200, to see the planet as a small greenish point. You will probably require at least a 10 inch telescope to resolve this blue-green point to a disk.