Neptune

Neptune is the eighth planet from the sun. It orbits at an average distance of 2,794 million miles (30 times farther than Earth). About 4 Earths would fit across the face of Neptune. Neptune is slightly smaller than Uranus and has a diameter of 30,775 miles. It takes 165 Earth years for Neptune to go around the sun one time, but only 16 Earth hours for it to spin on its axis once. The average temperature on Neptune is -370°F.

     The atmosphere of Neptune holds hydrogen (79%), helium (18%), and methane (3%). Methane gives Neptune its blue color. Neptune\'s atmosphere has a striped pattern like Jupiter and Saturn. Neptune once had a Great Dark Spot similar to Jupiter\'s Great Red Spot. To escape Neptune\'s gravity you need to travel 52,600 miles per hour. Johann Galle and Heinrich D\'Arrest discovered Neptune in 1846.

     Neptune has at least 8 moons. The two largest moons are Triton and Nereid. Triton is made of rock and ice. Its surface is rich in water ice, dry ice, and frozen carbon monoxide, methane, and nitrogen. Triton has cold geysers that spit nitrogen instead of the hot water that Earth geysers release. Neptune was the Roman god of the oceans.