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Our Solar System

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Neptune

Orbital semi-major axis is 30.07 A.U. pr 4498 million km.

 

Orbital eccentricity is 0.09.

 

Perihelion is 29.81 A.U. or 4460 million km.

 

Aphelion is 30.33 A.U. or 4537 million km.

 

Mean orbital speed is 5.43 km/s.

 

Sidereal orbital period is 163.7 tropical years.

 

Synodic orbital period is 367.49 solar days.

 

Orbital inclination to ecliptic is 1.77*.

 

Greatest angular diameter, as seen from earth is 2.4".

 

Mass is 1.02 1026 kg or 17.15 times that of Earth.

 

Equatorial radius is 24,766 km or 3.88 times that of Earth.

 

Mean density is 1638 kg/m3 or 0.297 times that of Earth.

 

Surface gravity is an incredible 11.14 m/s2 or 1.14 times that of Earth.

 

Escape speed is 23.5 km/s.

 

Sidereal rotation period is 0.67 solar days.

 

Axial tilt is an incredible 29.6*.

 

Surface magnetic field is 0.43 times that of Earth.

 

Magnetic axis tilt relative to rotation axis is 46.0*.

 

Surface temperature 59 k.

 

Number of moons: 8

 

Visited by Voyager 2 in 1986.

 

Atmosphere is 84 percent molecular hydrogen, 14 percent helium, and 3 percent

Methane.

 

Magnetosphere is about 100 times stronger than Earth's.

 

Has a rocky core surrounded by a layer of metallic hydrogen.