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Do know anything about Neptune? Why its named so? How close we are into its discoveries? Missions used for its discoveries etc. The page is all about this. 
Before we used to hear Pluto with Neptune while taking about planet but in year 2006, the international astronomical union (IAU) approved a new classification scheme for the celestial bodies in our solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Hence Neptune is the last planet in the solar system sitting out in space far away from the sun's hotness which is as far as 2.8 billion miles away and hence it is just out of our reach yet scientists have made lots of discoveries on this.


Based on its history, it is named after the roman god, Neptune who was the only a minor god. His counterpart, Poseidon was a powerful god and Neptune became his equal. Poseidon and Neptune, each carry a trident and rule over the seas, but Neptune was also a land god, concerned with fresh water and fertility. He was also responsible for earthquakes. He was even the husband of Demeter, the goddess of grain. Neptune's largest moon is named after Triton, a sea child of Poseidon.


What is Neptune?

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Have you ever observed the image of our solar system there comes the sun, its eight planets and a dwarf planet. In the list of the planets comes the word Neptune!

Neptune is the last planet of our solar system which stands as the eight one in order and is quite cold and windy. Like Jupiter and Saturn, they are also composed mostly of gases mostly ammonia, helium and methane and hence they three together known as ice giants as they contain icy water with methane and ammonia. Like Pluto, they cannot be seen without a telescope. The astronomers John Couch Adams and Urbain Le Verrier discovered Neptune independently using the work of mathematician Alexis Bouvard. It is named after roman god of the sea.

Moons of Neptune

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There are 14 moons that orbit around the planet Neptune which has seven inner moons namely Naiad, Thalassa, Galatea, Despina, S/2004 N1, Larissa and Proteus. Triton, the largest moon accompanied by other outer moons like Nereid, Halimede, Sao, Laomedeia, Psamathe and Neso. 

Moons of Neptune
Moons of Neptune

Triton, the Neptune's largest satellite, travels around the Neptune every six days in a circular orbit. Astronomers believe that Triton may have been a large comet that was captured by Neptune's gravity. Triton shows evidences of volcanoes that erupted water and ammonia which froze on the surface. Its surface temperature is -235o C, the coldest measured object in solar system. The volcanoes are observed to be still active there.

Facts about Neptune

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Neptune known as the eight planet is named after the roman god of the sea which is twin of Uranus but a non identical twin which is slightly smaller, but appreciably denser and more massive. Lets see some facts about Neptune:
It was discovered when astronomers were observing the orbit of Uranus. The Uranus orbit did not follow the normal pattern so the astronomers predicted that some larger planet was affecting Uranus's orbit. This observation gave out the discovery of planet Neptune.

It is a large, blue-green planet with an atmosphere containing mainly hydrogen, ammonia, helium and methane gases. Its core is mostly made up of ice and rocky layer looks similar to Uranus in color and composition. It can only be observed using telescope like Pluto.

It is 30 times as far from the sun as earth is, having the distance of 4.498 billion km from the sun. It travels in an elliptical orbit taking 165 earth years to complete one solar orbit. It also spins once on its axis about every 17 hours. It has diameter of 49,244 km which is the third most massive planet in the solar system. It is almost four times that of earth and is about 17 times as heavy.

The axis of Neptune tilts at about 28o. This causes the sun to heat the northern and southern hemisphere of the planet at different times, that results in to the seasons which may last as long as 40 years. Every 284 years once the dwarf planet Pluto moves inside the Neptune's planet for a period of about 20 years. At this time Pluto would be closer to the sun than Neptune.

It has 13 moons and one thin and three thick rings of dust particles. Among which, four moons orbit the planet within the rings. The largest moon is Triton which is around 2705 km in diameter and is 3,54,760 km from Neptune having an unusual orbit as it rotates in the direction opposite to the direction of rotation of Neptune.

The space probe, Voyager 2, passed within 4900 km of Neptune in 1989 and collected data about it and Uranus. The ring system was surveyed and the magnetic field was studied and lightning was detected from charged particle and aurora was found imaging the surface features. The six new satellites were discovered but they were some limitations as Hubble telescopes were not invented during those days.

Characteristics & Composition

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Neptune is known as twin of Uranus but it is non identical twin which is slightly smaller, but appreciably denser and more massive. Unlike Uranus, it has an internal heat source which sends out 2.6 times more energy than it would do if depended entirely upon what it receives from the sun. It does not share in Uranus unusual axial tilt, at the time of the voyager 2 pass it was Neptune's south pole which was in sunlight. The rotation period of just over 16 h is slightly shorter than that of Uranus. Well, if we deal with its composition like Uranus it is popularly known as ice giant which is made up of chunks of ice having hydrogen and watery layer containing traces of methane and ammonia. Temperature inside the core is around 9,260 F.

Neptune Exploration

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The Neptune exploration begun with the spacecraft Voyager 2 in 1989. In this mission only earth based telescopes were used as the Hubble Space telescopes were not introduced during voyager pass. The voyager 2 was launched not only to capture the information about Neptune but also about Jupiter, Saturn and Uranus. After exploring the Saturn in this mission the scientists predicted that that there is 60 % chance of exploring Uranus but not more than 40 % chance of exploring Neptune.

At 06.50 GMT on Aug 1989 Voyager 2 passed over the darkened north pole of Neptune, at a minimum relative velocity of 17.1 km/s. At that time the spacecraft was 29,240 km from the center of Neptune, no more than 5000 km above the cloud tops, and 4425000000 km from earth so that the light time was 4hr 6min. Before the closest approach over the North Pole, many discoveries were done like ring system was surveyed and magnetic field was studied, lightning was detected from charged particle and aurora was confirmed at the same time surface features were imaged giving out the discovery of six satellites.
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