Neptune(eighth Planet from Sun)

Neptune  

The Neptune is the farthest Planet in the Solar system, which is the eighth Planet in the Solar system. This densest giant Planet, has the third largest mass, in the Solar system.

Structure of Neptune

Like the Uranus, the Neptune contains the rock and the ices primarily in its inner surface. The Neptune and the Uranus are considered, as the ice giants. This Planet appears blue due to the traces of methane in its outermost layer. The atmosphere of this planet, has a visible and an active weather patterns, unlike the Uranus, which has the featureless atmosphere.

History

            It was difficult to model the formation of the ice giant Planets, the Neptune and Uranus. The current model tells that the matter density in the outer layer of the Solar system , was less to cause the formation of the large bodies, from the core accretion method. The instability inside the protoplanetary disc and the blast of atmosphere  by radiation from the nearby star, must have led to the formation of the giant objects.            

Features

The Neptune is the fourth largest Planet, by its diameter. It is 17 times that of the Earth, which is little larger than its twin Planet Uranus. This Planet is smaller and denser than the Uranus, due to its greater mass, which causes the gravitational confinement of its atmosphere.  This planet takes 164.8 years to orbit the Sun, at a distance of 30.1AU. This Planet, got its name “Neptune” from the Roman god of  Sea. Like the other planets, the winds cause the weather patterns of this Planet. This Planet has a wind speed of  2100Km/h.

Atmosphere of Neptune

            The atmosphere of this planet, contains the Hydrogen and the Helium, like the gas giant Planet Saturn.  It also contains the nitrogen and least traces of Hydrogen. The water, methane and the ammonia are found in the form of high ratio of ices. Then the outer atmosphere of the Neptune is one among the coldest places, because of its farthest distance from the Sun. The temperature at the top of the cloud is 55K, whereas it is 5400K in the middle of the Planet. This Planet has a faint ring system, called  the arcs, which was discovered in 1984.     

Orbit of Neptune

            The orbit of the planet, impacts directly on the Kupier belt region. This Kupier belt is the ring made up of ice, extending from the orbit of Neptune, at 30AU to 55AU from the Sun. In the same way, the gravity of the Jupiter governs the asteroid belt and shape its structure, the Neptune’s gravity governs the Kupier belt. The elliptical orbit of the Neptune is 1.77degrees inclined, than that of Earth. Then the axial tilts of this Planet, is also similar to that of the Earth and the Mars. For this reason, Planet gets the seasonal changes, similar to that of the Earth.

Moons of Neptune

            This planet has 14 natural satellites or moons. Among these moons, the Triton is the largest moon, containing above 99.5% of  mass in the Neptune orbit. The Triton is spherical in shape, which was discovered by the William Lassel, after 17 days of discovery of Neptune. The other 13 moons were identified telescopically till the 20th century.

Perihelion and Aphelion

The Planet Neptune holds the Perihelion of 4.46billion Km or 29.81 AU , which is the nearest  approach to the sun. This Planet has  the Aphelion of about 4.54billion Km or 30.33AU,  which is the farthest distance  from the sun.

Research         

On 25th 1989, the Voyager 2 flew through the Neptune. The Hubble Space Telescope and the ground-based telescopes have allowed for the observations, to study the Neptune. The study using the earth based telescopes was challenging because of its distance from the earth. The Voyager2 is the only spacecraft, to fly by the Neptune. On 23rd September 1846, Neptune was seen using the telescope, by Johann Galle below a position estimated by the Le Verrier. This Planet, cannot be seen through the naked eyes and is the only Planet found by the mathematical estimation, rather than the empirical observation. When the Voyager2 fly by this Planet, the southern hemisphere of the Planet had a Great Dark spot, while the Jupiter had the Great red Spot.

Position in the solar system: Eighth Planet in the solar system.

Features: Shape – spherical

                  Time taken by Neptune to orbit the Sun – 164.8 years.       

                  Perihelion – 29.81A.U, Aphelion – 30.33A.U.