411 REFERENCE · Wikibooks
Solar System/Neptune
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
thumb|Photo of Neptune.
Neptune is the farthest of the eight planets from the Sun and is the fourth largest, with a diameter of 49572 kilometers (3.9 times that of Earth). It is one of the four gas giants. If Neptune had a solid surface and you stood on it, you would weigh 12% more than you do on Earth.
Orbit
Neptune orbits the sun once every 164.79 Earth-years, at an average distance of 30.06 AU (Earth-Sun distances) and with an orbital eccentricity of 0.010, making its orbit more nearly circular than that of any other planet except Venus. Neptune is so far away from the Sun that light from the Sun takes an average of 4 hours 10 minutes 25 seconds to get to Neptune.
Rotation
Neptune rotates about its axis prograde (in the direction of its solar orbit) once every 16 hours 6.5 minutes, at an axial tilt of 28.31°.
Physical characteristics
Atmosphere
Spots and clouds
thumb|Great Dark Spot of Neptune.
Cloud layers
thumb|High altitude clouds of Neptune cast shadows on lower clouds.
Winds and currents
Temperature
Magnetic Field
Rings, arcs and dust
thumb|Ring system of Neptune.
Satellites
Triton
thumb|Triton
Surface
Surface Relief Features
Activity on Triton
Nereid, Proteus, and Larissa