Neptune

Neptune, as seen from https://commons.wikimedia.org/wiki/File:3D\_Neptune.png

## Simple Introduction

Neptune is the 9th Planet from the sun, when Ceres is counted as just a sub-section of planet category, 8th in traditional terms, and 10th when Pluto gets closer to the sun then it. It is blue in color, and is an Ice Giant, along with Uranus, and was discovered in 1846. Neptune has the fastest win speeds in the entire solar system.

## Description

**Neptune** is the eighth and furthest planet from the Sun. Neptune is an ice giant like Uranus but with a darker tint of blue. Neptune was discovered September 23, 1846 by 3 astronomers: John Couch Adams, Urbain Le Verrier, and Johann Galle. Neptune has around 14 known satellites. Its biggest moon is Triton, although there could be even more then just 14… Neptune is famous for having the fastest wind currents in the Solar System, speeding up at a velocity of just under 2000 kilometers per hour. Neptune has 120 trillion pieces of ice discovered on October 18, 1996.

### Rotation and orbit around the sun

Neptune makes only one orbit around the Sun in about 164.8 earth years. This is because Neptune is more than two billion miles from the Sun. Because of its gaseous nature, Neptune's equatorial rotation is equal to about 18 Earth hours. Yet since the wind speeds towards the poles are faster, the polar rotation is equal to around 12 Earth hours.

### Atmosphere and Composition

Neptune's atmosphere is composed of the same materials as Uranus, methane and ammonia, with small amounts of ice inside the inner atmosphere and its core composed of mostly metallic materials and rock. Because Neptune and Uranus are so similar, they have been de-categorized from the term of gas giants like Jupiter and Saturn, and Neptune and Uranus have been categorized with the term of ice giants, due to there being an exceptional amount of freezing compounds of carbon and ammonia in the atmosphere, which can lead to frozen water in the atmosphere and the surface.

## Rings

Neptune has its own rings, being the 4th and final gas giant to have any rings, although not the farthest out to possess such beautiful structures around their object. These rings were discovered in the La Silla Observatory in Chile by Reinhold Häfner, Patrice Bouchet, and Jean Manfred, on July 22, 1984. These rings very lowly dense. Even at their densest, they are only as dense as the lesser dense parts of Saturn's rings. The innermost moons in the rings include Despina, Naiad, Thalassa, and Galatea. The outermost moons in the rings include Larissa and Prometheus.

## Discovery

Sightings of Neptune have been traced back to Galileo Galilei in 1612. He did not list it as a planet, but as a star, next to other stars, so he is not credited with the discovery. He did record its movement relative to the stars.

In 1821, Alexis Bouvard crated tables of Uranus. some observations and discoveries revealed substantial deviations from the tables, leading Bouvard to hypothesize that a so far undiscovered object was moving the orbit via a gravitational interference. In 1843, John Couch Adams began work on the orbit of Uranus using the data he had around. He requested some data from Sir George Airy, the Astronomer Royal, who supplied it in February 1844. Adams continued to work in 1845–1846 and produced several different estimates of a new planet. In 1845–1846, Urbain Le Verrier, independently of Adams, developed his own calculations but aroused no enthusiasm in his compatriots. In June 1846, upon seeing Le Verrier's first published estimate of the planet's longitude and its similarity to Adams's estimate, Airy persuaded James Challis to search for the planet. Challis vainly scoured the sky throughout August and September. Challis had, in fact, observed Neptune a year before the planet's subsequent discoverer, Johann Gottfried Galle, and on two occasions, 4 and 12 August 1845. However, his out-of-date star maps and poor observing techniques meant that he failed to recognise the observations as such until he carried out later analysis. Challis was full of remorse but blamed his neglect on his maps and the fact that he was distracted by his concurrent work on comet observations.

At the same time, Verrier sent a letter and asked a Berlin Observatory astronomer Galle to search with the observatory's refractor. Heinrich d'Arrest, a student at the observatory, suggested that Galle could compare a recently drawn chart of the sky in the same area of Le Verrier's predicted location with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. On the evening of 23 September 1846, the day Galle received the message, he had been able to discovered Neptune

In the wake of the discovery, there was a heated nationalistic rivalry between the French and the British over who deserved credit for the discovery. Eventually, an international consensus emerged that Le Verrier and Adams deserved joint credit.

### Naming

Struve came out in favour of the name *Neptune* on 29 December 1846, to the Saint Petersburg Academy of Sciences. Soon, *Neptune* became the internationally accepted name. In Roman mythology, Neptune was the god of the sea, identified with the Greek Poseidon.

## Storms on Neptune

### The Great Dark Spot

The **Great Dark Spot**, is a dark spot on the surface of the planet, Neptune. This one has many similar characteristics to the more famous, and commonly mistaken for, Great Red Spot. One example of a similarity is the category of the storm, for they are both anticyclonic storms, or storms that rotate different directions than that of regular storms, which are referred to as cyclonic. The first sighting of the spot was observed by the Voyager 2 probe in 1989. The interior of these spots are cloud-free compared to that of Jupiter's Great Red Spot, which densely packed with dust-filled clouds. Winds in this storm are the fastest in the Solar System, being 1500 miles per hour. The dimensions of the GDS were estimated by scientists in 1995. The dimensions measured were 15,900 x 9870 x 8350 x 4100 miles.

#### Disappearance

In November of 1994, the Hubble Space Telescope failed to photograph the GDS, leading scientists to believe that it has disappeared. Many theories surround this disappearance - one such theory claiming that due to the high wind speeds of the cyclones, as well as their close proximity to one another, the storms all pushed themselves into different directions. Another one is that they were covered up by an abundance of dust kicked into the atmosphere.

### The NGDS

After the disappearance of the main Great Dark Spot, a new, similar spot formed the northern hemisphere of Neptune. It was given the name of the Northern Great Dark Spot, or NGDS. It is the last one remaining, and has lasted several years.

## Exploration

Voyager 2 is the only probe and/or manmade thing that has visited Neptune. The spacecraft's nearest approach to the planet occurred on 25 August 1989, getting only 3,000 kilometers away from the north pole of the planet. Because this was the last planet the spacecraft was able to actually visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly to what was done for Voyager 1's encounter with Saturn and its largest moon, Titan. The images relayed back from Voyager 2 to Earth became the subject of a 1989 PBS all-night program, Neptune All Night.

## Formation & Early History

Neptune was created when Neptune’s core formed from a clump of rocky material that was around 2 ~ 5 times in Earth's mass. Its core gathered enough gas to become a Jovian planet. A few billion years ago as well, Neptune became further out the Uranus, and also captured Triton from a binary system of 2 dwarf planets.

## Future

In a few million years, Neptune’s rings are going to dissipate. Theres a infinitely small, unrealistic possibility that Pluto could collide with Neptune, although that is extremely unrealistic, and entirely fictional. In around 4 billion years, Triton will collide with Neptune, and form new rings, like Saturn’s, or at-least Uranus’s. In 10 billion+ years, Neptune will be ejected from the solar system, after that, it is unsure what will happen to Neptune, it may be sucked up by a black hole, but it is uncertain.