NEPTUNE: Azure Giant Gas Planet

Group 7 of Grade V-Humility 2011-2012 Neptune is an azure giant gas planet, which is made up of various ices such as water, ammonia and methane and rock. It is the eighth planet from the Sun and the fourth largest (by size) of the eight planets. It is smaller in size but it's heavier than Uranus. It is nearly 4 times the size of Earth and is 17 times the Earth’s mass. Its revolution takes 164.79 Earth days. Neptune has 13 known moons; 12 small ones and a large moon called "Triton." Triton has an estimated temperatures of -235.2 °C (38 Kelvin). Some other moons are Nereid, Naiad, Thalassa, Despina, Galatea, Proteus, Sao, Laomedeia, Halimede, Psamathe, Neso, and Larissa. As Neptune is the Roman god of the seas, the moons are named after lesser sea gods. Neptune is the first planet found by mathematical prediction rather than empirical observation. Its astronomical symbol is a stylized version of the god Neptune’s trident. In Roman mythology, Neptune was the god of the Sea. He is known as Poseidon in Greek mythology. The planet was probably named after the sea god because of its deep blue color. Its moon is probably named Triton for in Roman Mythology, his immortal son’s name is Triton. Neptune's blue color is the result of a gas called methane in its atmosphere. Like the other gas planets, it has rapid winds trapped in "bands" of latitude and large storms. Neptune's winds are the fastest in the solar system, reaching 2000 km/hour. It, along with Uranus is classified as “ice giants”. Neptune has been visited by only one spacecraft, Voyager 2 on Aug 25, 1989. Almost everything we know about it comes from this one visit. At the time of Voyager 2's flyby, Neptune's most outstanding feature was the "Great Dark Spot" in the southern hemisphere. It was about half the size as Jupiter's "Great Red Spot" - about 1 Earth would fit into it. Neptune's winds blew the Great Dark Spot westward at 300 meters/second (700 mph). It suffers the most violent weather in our Solar System. Storms have been spotted swirling around its surface and freezing winds that blow about ten times faster than hurricanes on Earth make it the windiest planet. Voyager 2 also saw a smaller dark spot in the southern hemisphere and a small irregular white cloud that zipped around Neptune every 16 hours or so now. This feature is known as "The Scooter." During Voyager 2’s visit, they found out that its mass is 17 times of Earth yet only 1/19th of Jupiter’s. Neptune has an equatorial radius of 24764 km. Neptune’s atmosphere is 80% hydrogen and 19% helium. Trace amounts of methane can also be found. Neptune has a planetary ring system, though one much less substantial than that of Saturn. The rings may consist of ice particles coated with silicates or carbon-based material, which most likely gives them a reddish hue. The three main rings are the narrow Adams Ring, 63000 km from the center of Neptune, the Le Verrier Ring, at 53000 km, and the broader, fainter Galle Ring, at 42000 km. A faint outward extension to the Le Verrier Ring has been named Lassell. The Arago Ring at 57000 km bound it at its outer edge. The outermost ring, Adams, contains five prominent arcs now named Courage, Liberty, Equality and Fraternity. The axial tilt of Neptune is 28.32°,[95] which is similar to the tilts of Earth (23°) and Mars (25°). As a result, this planet experiences similar seasonal changes. Recently, however, the Hubble Space Telescope (HST) showed that the Great Dark Spot has disappeared! Scientists think that it has either dissipated (like our storms do) or is currently being hidden by Neptune's atmosphere. Also, HST discovered a new dark spot in Neptune's northern hemisphere. This shows that it's atmosphere changes rapidly. Neptune also has rings. The Voyager 2 spacecraft showed scientists that it indeed has complete rings with bright clumps. Like Uranus and Jupiter, Neptune's rings are very dark and very faint. Scientists still haven't figured out what they are made of yet. Neptune can be seen with binoculars (if you know exactly where to look) but a large telescope is needed to see anything other than a tiny disk. But did you know that there were many suggestions on what to name Neptune? Some name suggestions are Janus, the 2 headed god of choices, Oceanus, the titan of oceans, and Le Verrier, in honor of the person who discovered Neptune. ( This article was taken from various sources)