Neptune

The smallest and most distant of the "gas giant" planets. Neptune has much in common with its three huge neighbors Jupiter, Saturn, and Uranus. It has strong winds, several light and dark spots on its surface, an internal heat source, rings, and moons. Neptune's Great Dark Spot is a storm about the size of the Earth.

Diameter: 31,000 miles
Location: 8th planet from Sun
Average Distance from the sun: 2.8 billion miles
First observed: 1846
Cloud Top Temperature: -300°F
Number of Moons: 8
Orbital Period: 165 years
Characteristics: gaseous blue planet with storms and winds reaching 400 miles per hour
Significance: 4th largest planet in solar system

Image credits: courtesy of JPL, California Institute of Technology and NASA; Frank Summers: AMNH.