Neptune

Picture
The Planet Neptune is the eighth planet from the sun. It is also known as the Blue Giant. Neptune is the fourth and outermost of the gas giant planets and also has rings. Its atmosphere is mostly hydrogen and helium. In Roman mythology Neptune was the god of the Sea.


Neptune has been visited by only one spacecraft, Voyager 2 on Aug 25 1989. It was the last stop in 1989 for the Voyager 2 spacecraft on its grand tour of the solar system.

Recent knowledge has been gained by ground-based telescopes and the Hubble Space Telepscope.

Due to Pluto's eccentric orbit, Neptune at times becomes the most distant planet from the Sun for a few years.

Planet Neptune Facts:

Mass: 17.15 Earth-masses

Number of known satellites: 8

Length of Year: 164.8 Earth-years

Mean Distance from the Sun: 4,500 million kilometers

Mean Orbital Velocity: 5.4 kilometers per second

Length of Day: 16.11 hours, 0.67 Earth-day

Equatorial diameter: 49,500 kilometers Atmospheric components: 74% hydrogen, 25% helium, 1% methane

Moons of Planet Neptune

Neptune has 8 known moons: Triton, Thalassa, Naiad, Despina, Galatea, Larissa, Proteus and Nereid

Triton has the coldest temperatures in the solar system. Voyager observed geysers. The Great Dark Spot Voyager 2 observed the Great Dark Spot. Recent observations made with the Hubble Space Telescope indicate that the Great Dark Spot no longer exists.