Neptune

Neptune is the eighth and farthest planet in the solar system. It was discovered in 1846 and has the distinction of being the first planet to be found by mathematical means rather than by direct observation through a telescope. Up until 2006, it was the second last planet, at which time it was determined that Pluto did not meet the conditions for having planet status. Although it is quite a large planet, it does not match the size of Saturn or Jupiter, yet it is larger than Uranus. You cannot see this planet with the naked eye and through a telescope it appears as a blue disc.

Neptune is about 2,8 billion miles from the sun and is about 17 times as large as the Earth. Scientists believe that clouds made up of gases surround the planet. The combination of these gases and the radiation from the sun results in the bluish appearance.

The inner core of Neptune is made of rock, with a layer of ice around it. This layer oif ice is then surrounded by molecular hydrogen. It takes about 165 years for the planet to revolve around the sun. However, it rotates on its axis much faster at once every 15 or 16 hours. Both the revolution and the rotation are in the same direction and not in the opposite direction like Uranus.

The winds of Neptune are the strongest in the solar system and can reach speeds of up to over 2000 km per hour. It does have a large dark spot quite similar to the red spot on Jupiter. The average temperature on the surface of the planet is about -218ºC, making it the coldest planet.

Like the other large planets, Neptune also has rings. The structure of the rings seems to be very clumpy, although scientists are not sure if what may be casing this to happen. The ring farthest out from the planet has five arcs, and again these have not been explained. Neptune also has 13 moons, the largest of which has a retrograde orbit. This signifies that the moon came from some other part of space and was captured by the gravitational pull of the planet.

The rotation of Neptune has an effect on the area beyond it in space, which is the Kuiper Belt. The gravitational pull of the planet has cause parts of this belt to become unstable, thus creating gaps in the belt.