Sheri Ann Seiler, age 10, of Colwich, Kansas, for her question:

What kind of planet is Neptune?

Neptune is a big, bleak world of icy frost. It is the eighth planet from the sun and about 30 times farther than we are from the sun's warmth and brilliance. Astronomers suspect that the temperature on the cloud tops  is around minus 210 degrees Centigrade and almost everything is solid ice. The days and night cycle  is shorter than ours and lasts 17.2 hours. Neptune dawdles around the sun like a slowpoke and takes almost 165 years to finish each yearly orbit.

Neptune is one of the four giant planets of the Solar System, but it is too far away to be seen by human eyes. The big fellow is 60 times bigger than the earth and if we know just where to find it in the sky, we can see it through a telescope. It looks like a big round ball of pale greenish yellow. Photographs taken with the help of planetary spacecraft show faints rings and thirteen moons are orbiting around the big, cold planet. One of them is much bigger than our own golden moon.  The following are the latest statistics on Neptune.

Neptune Statistics

Planetary Symbol: Name in Roman/Greek Mythology: Neptune/Poseidon

Diameter: 49,493 km (30,760 miles) Rotation Period about Axis: 17.24 hrs

Mass: 102.4x10^24 kilograms (17.2 x Earth's) Revolution Period about the Sun:165 years

Density: 1,638 kg/m^3 Tilt of Axis: 29o 36"

Minimum Distance from Sun: 4.46 billion km

(2.77 billion miles) Surface Gravity: 11 m/s^2 (1.12 x Earth's)

Maximum Distance from Sun: 4.54 billion km (2.82 billion miles)

Temperature at Cloud Tops: -210 degree C ( -346 degrees F)

Orbital Semi-major Axis: 30.07 AU (Earth=1 AU) Average Cloud Top Temperature (K): 63K

Minimum Distance from Earth: 4.3 billion km (2.68 billion miles)

Satellites/Rings: 13 known moons, faint rings