Neptune
Neptune was first officially discovered by Frenchmen Urbain Le Verrier. Neptune is essentially a duplicate of Uranus. However Neptune was first observed by Galileo. Neptune lies 2,788,000,000 miles from the sun. Because of this distance neptune's temperture is -360 degrees F. Neptune has two moons, Triton and Nereid. The orbital period of Neptune is 165 years. The atmosphere of Neptune is made up mostly of hydrogen, helium, methane, and ethane. It is also thought that Neptune may have concentrations of ammonia.