NEPTUNE

MASS: 17.2 times Earth
DIAMETER: 30,775 miles
ROTATION: 19 hours, 12 minutes
ORBIT AROUND SUN: 165 Earth years

Neptune is the Eighth planet from the Sun. Since Pluto has such an unusual orbit, sometime Neptune is the ninth planet away from the Sun. It is the smallest of the gas planets (which include Jupiter, Saturn, and Uranus). The core is made of molten rock but the majority of the mass consists of hydrogen, helium, methane, and ice. As with Uranus, it is the methane gas that gives Neptune its blue color. Like the other gas planets, it is covered with the bands of coloured clouds and like Jupiter, Neptune did have a dark spot in the southern hemisphere. Although it didn't last nearly as long as Jupiter's Red Spot, there have been other spots seen in the northern hemisphere. The winds on Neptune are the fastest than on any other planet blowing up to 1,500 miles per hour.Like Uranus, Neptune's seasons last a long time, 40 years. During the southern summer the south pole is in a constant sunlight for about 40 years and in the northern summer is in constant sunlight for about 40 years. Similar to Uranus, Neptune's magnetic field is tilted 47 degrees away from the planet's spin axis and offset from the planet's center by about half its radius.Neptune has four rings all with different widths. Since some places have more particles than others these rings form arcs surrounding Neptune. The outermost ring is called Adams (which contains three prominent arcs named Liberty, Equality, and Fraternity), the next ring is an unnamed ring the orbits with the moon Galatea, then Leverrier (whose outer extensions are called Lassell and Arago), and finally Galle. All of Neptune's rings are fairly young and relatively short-lived.Neptune has eight known moons. The largest moon Triton orbits Neptune in the opposite direction to the planet's rotation direction. It is gradually getting closer until it eventually collides with Neptune in about 10 to 100 millions years, forming vast rings around Neptune that will rival or exceed Saturn's extensive ring system. The surface of Triton has many geysers that spew gaseous nitrogen. Scientists believe the cause of the geysers is because of the solar melting of the material below the surface's nitrogen ice. The ice turns to gas and explodes into space through vents in the crust. As the gas rushes toward the vent, bits and pieces of dust from the subsurface are carried along and shot into the sky. The dust then settles down on the surface, forming dust streaks found on many parts of Triton's surface. It is also the coldest body visited in our solar system with an average temperature of -391 degrees F.