Neptune

Basic Facts:
Moons: 13

Period of Rotation: 16 hours

Period of Revolution: 165 years

Inner/Outer planet: Outer

Terrestrial/gaseous planet: gaseous

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

Atmospheric composition: hydrocarbons, hydrogen, helium

Core composition: methane ice?

Mass: 17.2 x Earth's mass

Diameter: 30,760 mi (49,493 km)

Temperature at cloud tops: -346 degrees F

Gravity: 1.12 x Earth's gravity

Discovered by: Galle and d'Arrest in 1846

Tilt of axis: 29 degrees

Planetary symbol:











   


Missions: Voyager II

Uranus has a Great Dark Spot similar to Jupiter's Great Red Spot.  Scientists think that the Great Dark Spot is a hole in the methane deck of Neptune's atmosphere,kinda like the hole on Earth's ozone layer.  Uranus is the smallest gaseous planet, and believe it or not, Triton, one of Neptune's moons, is colder than Neptune, and Neptune is REALLY cold.