He was named after the well-known Olympian god of the sea and is one of the remotest planets of our solar system. The eighth planet from the Sun and the fourth in size gas giant was discovered in 1846 when astronomers suspected the presence of an unknown celestial body that affected the orbit of planet Uranus.

Average distance from the Sun: 4.5 billion km
Distance from Earth: Minimum 4.31 billion km, Maximum 4.68 billion km
Mass: 17.2 times the mass of Earth
Diameter: 49,528 km
Day duration: 16.1 earth hours
Year duration: 164 earth years
Temperature: -2180 Celsius
Atmosphere: Hydrogen, helium, methane
Surface gravity: 1.14 times that of Earth (If on Earth you weigh 70kg, on Neptun's surface you would weigh 80 kg)
Known satellites: 8