Neptune, named for an ancient Roman sea god, is a stormy blue planet about 30 times farther from the Sun than Earth. Neptune was discovered when astronomers realized that something was exerting a gravitational pull on Uranus, and that it was possible that an unknown planet might be responsible.
- Size: About 4 times the size of Earth
- Diameter: 30,775 miles (49,528 km)
- Surface: A liquid layer covered with thick clouds and with constant, raging storms
- Atmosphere: Hydrogen, helium, methane, and ammonia
- Temperature: –353°F (–214°C)
- Rotation of its axis: 16 hours and 7 minutes
- Rotation around the Sun: 165 Earth years
- Your weight: Not known
- Distance from Earth: 2,680,000,000 miles at closest point
- Mean Distance from Sun: 2,796.46 million miles (4,497 million km)
- Satellites: 8
- Rings: 4
