Neptune Full
Adjective(s) Neptunian
Orbital properties
Aphelion/apoapsis 4 553 946 490 km (about 30,441 AU)
Perihelion/periapsis 4 452 940 833 km (about 29,766 AU)
Semi-major axis 4 503 443 661 km (about 30,103 AU)
Orbital eccentricity 0.011214
Orbital period 164,79 years (60190 days)
Average orbital speed 5,43 km/s
Physical properties
Radius 24 764 km (equatorial); 24,341 (polar)
Mass 5,15 x 10^26 kg 17,147 earth masses
Mean density 1,638 g/cm³
Escape velocity 23,5 km/s
Rotation period 0,6713 days (16 hours, 6 minutes, 36 seconds)
Average surface temperature 55 degrees Kelvin ( 218.15 °C)
Apparent magnitude 8.02 (minimum), 7,78 (maximum)
Moons 14

History and DeathEdit

After Uranus was discovered, astronomers were perplexed by its strange orbit. They concluded that there must be a planet farther out than Uranus. Neptune was discovered on September 23, 1846, by many astronomers that helped find the planet Neptune. It was observed many times before it was officially announced, the earliest being in the 1600's when Galileo charted it's movements but failed to realise it was a planet. Now Planet Neptune is dead. It exploded. 


  • Neptune's largest moon is Triton.
  • Neptune is similar in size to Uranus.
  • Neptune is the smallest Gas Giant in our Solar System.
  • Neptune is not visible to the naked eye.
  • Neptune is named after the Roman God of the seas, because of Neptune's blue color.
  • Neptune has 14 known moons as of 2013.
  • If you could stand atop Neptune's clouds, you would realise that the gravitational pull is very similar to Earth's. The mass is spread out over a larger area, so it almost resembles Earth's gravity except you would fall through Neptune's clouds as it has no solid surface.
  • Neptune's winds can reach 2,100 km an hour, making it the windiest place in the solar system. 
  • Pluto is sometimes closer to the sun than Neptune is,  due to Pluto's strange orbit.
  • A year on Neptune lasts 165 Earth years.



  1. Naiad
  2. Thalassa
  3. Despina
  4. Galatea
  5. Larissa
  6. S/ 2004 N1
  7. Proteus
  8. Triton
  9. Nereid
  10. Halimede
  11. Sao
  12. Laomedeia
  13. Psamathe
  14. Nesco
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