Neptune

The Mystic

  In Roman mythology was Neptune the God of the Sea. In Greek was Neptune: Poseidon.

  Neptune is the eight planet in order of distance from the Sun and the fourth largest.

  After the discovery of Uranus, it was noticed that its orbit was not as it should be in accordance with Newton´s laws. Therefor it was predicted that another more distant planet must be perturbing Uranus´ orbit. Neptune was first observed by Galle and Heinrich D´Arrest on 1846, September 23 very near to the locations independently predicted by Adams and Le Verrier from calculations based on th observed arose between the English and French over priority and right to name the new planet; they are now jointly credited with Neptune´s discovery. Subsequent observations have shown that the orbits calculated by Adams and Le Verrier diverge from Neptune´s actual orbit fairly quickly. Had the search for the planet taken place for a fw years earlier or later it would not have been found anywhere near the predicted location.

  The only spacecraft that has visited Neptune is Voyager 2 on August 25 in 1989. Almost everything we know about Neptune comes from this spacecraft.

  Because Pluto´s orbit is so eccentric, it sometimes crosses the orbit of Neptune making Neptune the Most distant planet from the Sun for few years.

  The composition of Neptune is probably similar to Uranus´: various "ices" and rock with about 15% hydrogen and a little helium. Like Uranus, but unlike Jupiter and Saturn, it may not have a distinct internal layering but rather to be more or less uniform in composition. But there is most likely a small core, about the mass of the Earth, of rocky material. Neptune´s atmosphere is mostly hydrogen and helium with a small amount of methane.

  The blue colour of Neptune is the result of absorption of red light by methane in the atmosphere.

  Neptune, like other typical gas planets, has rapid winds confined to bands of latitude and large storms or vortices. Neptune´s winds are the fastest in the solar system, reaching about 2000 km per hour.

  Neptune has an internal heat source, like Jupiter and Saturn. It radiates more than twice as much energy as it receives from the Sun.

  At the time of the Voyager encounter, Neptune´s most prominent feature was the Great Dark Spot in the southern hemisphere. It was about half the size of Jupiter´s great red spot. Neptune´s winds blew the Great Dark Spot westward at 300 meters per second. Voyager 2 also saw a smaller dark spot in the souther hemisphere and a small irregular white cloud that zips around Neptune every 16 hours or so now known as "The Scooter". It may be a plume rising from lower in the atmosphere but its true nature remains a mystery.

  Hubble Space Telescope observations of Neptune in 1994 has show that the Great Dark Spot has disappeared!! It has either simply dissipated or is currently being masked by other aspects of the atmosphere. A few months later HST discovered a new dark spot in the northern hemisphere. This indicates that Neptune´s atmosphere changes very rapidly, perhaps due to slight changes in th temperature differences between the tops and bottoms of the clouds.

  Neptune has rings. Earth-based observations showed only faint arcs instead of complete rings with bright clumps. One of the rings appears to have curious twisted structure.

  Neptune´s rings are very dark but their composition is unknown.

  The rings have been give names: the outermost is Adam, next is an unnamed ring coorbital with Galatea, than Leverrier, and finally the faint but broad Galle.

  Neptune´s magnetic field is oddly oriented and probably by motions os conductive material, probably water, in its middle layers.

  Neptune can be seen with binoculars, if you know where to look, but telescope is needed to see the tiny disk.

  Neptune has 8 known moons; 7 small ones and Triton.

| Home | The Planets | Mercury | Venus | Earth | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto |