Neptune: The Blue Planet

Neptune is usually the eight planet from the sun, but every 248 years Pluto will move inside Neptune's orbit for about twenty years. Currently, Neptune is the ninth planet from the sun (it is the twenty year period) and will remain that way until March 15, 1999. Neptune is thirty times as far from the sun as the earth and cannot be seen without a telescope.

General information on Neptune:

• Diameter (miles)= 30,200
• Mass (trillion trillion lbs)= 227.1
• Density (earth=1)= .30
• Gravity (earth=1)= 1.13
• Period of Rotation (hours)= 17.7
• Escape Velocity (mph)= 52,794
• Major Atmospheric Gas= Hydrogen
• Inclination of Equator (degrees)= 29.0
• Known Moons= 2
• Mean Orbital Velocity (mph)= 12,147
• Minimum Distance From Sun= 2,771 (millions of miles)
• Maximum Distance From Sun= 2,819 (millions of miles)
• Mean Distance From Sun= 2,794.4 (millions of miles)
• Period of Revolution (earth years)= 164.79

Detailed information on Neptune--

Surface and Atmosphere:

It is believed that Neptune is made chiefly of hydrogen, helium, water and silicates . Silicates are the minerals that make up most of earth's crust. Astonomers believe the atmosphere is about 2,000 miles thick. The clouds of Neptune may consist of frozen ammonia, or combinations of crystals of ice, frozen methane and frozen ammonia. Temperatures on Neptune are much lower than that of earth and so animals that live on earth are not likely to be found there.

Satellites--

Neptune as two satellites which travel around it. One, Triton is close to 3,000 miles in diamter. It has a circular orbit and makes its revolution around Neptune in about six days. The other satellite, Nereid, is only 150 miles in diameter. It is three and a half million miles from the planet. It takes about 360 days to travel around Neptune; nearly one earth year.