Neptune Facts: 30 Captivating Facts About Neptune

Neptune is dark and cold and is among the eight planets in the solar system. Neptune has some features and characteristics that set it apart from other planets. With these 30 facts about Neptune, let us learn more about it.

1. Location: Neptune is the eight and the farthest planet from the sun. However, in 1930, after the discovery of Pluto, the title of the most distance planet from the Sun was snatched from Neptune and was given to Pluto. However, once again, in 2006, when Pluto was re-classified as a dwarf planet, Neptune became the most distant planet from the Sun.

2. Ice or Gas? Neptune is the smallest of the ice giants. Uranus is the other ice giant.

3. Discovery: Neptune was not known to the ancients, and until 1846, its position was determined with the help of mathematical predictions. Galileo had predicted the presence of a star in his drawings however he did not conclude that it was actually a planet.

4. Sighting the planet in the sky: Neptune cannot be seen in the sky with the naked eye because of its extreme distance from the Earth.

5. Around the Sun: Neptune takes 165 Earth years to complete its orbit around the sun.

6. Pluto vs Neptune: during the time Neptune makes three orbits around the Sun, Pluto makes two.

7. Magnetic field: Neptune’s magnetic field is 27 times more powerful than that of the Earth.

8. Which color? the characteristic color of Neptune is blue which is due to the presence of Methane on the planet. Uranus, on the other hand, is greenish-blue.

Also read: facts about Uranus

9. How many rings? Neptune has 6 known rings. These rings were confirmed by Voyager 2 in 1989. However, these rings vary in thicknesses and are supposed to be short-lived and relatively young.

10. Moons are many: Neptune has thirteen (13) officially confirmed moons and one unconfirmed moon.

facts about Neptune: Neptune's Interior
Neptune’s Interior. Image credit – Lunar and Planetary Institute

11. Neptune’s biggest moon: Triton, Neptune’s biggest moon, revolves in opposite direction to that of Neptune’s other moons. It is the only large moon in the solar system that has a retrograde orbit.

12. Today’s moon, Tomorrow’s ring: Triton is slowly spiraling inward towards the planet. It is estimated that Triton, after a few billion years, will eventually be torn apart by the planet’s gravitational force and a ring will be formed as a result.

13. No solid surface: because Neptune is a gas giant, there is no solid surface on Neptune for spacecraft to land on the planet.

14. Diameter and Mass: Neptune is the fourth largest planet in terms of diameter and third largest in terms of mass.

15. Naming the planet: Neptune is named after the Roman god of the Sea because of its bluish appearance.

16. Change of name: Neptune was initially called “Le Verrier” after the name of the scientist – Jean Joseph Le Verrier – who discovered it. However, this name of the planet was abandoned and it was finally named Neptune.

17. Neptune vs Jupiter: did you know that Neptune has the second largest gravitational force in the solar system after Jupiter?

Related: facts about Jupiter

18. Exploration by spacecraft: just one mission has been sent to Neptune in 1989. Maybe because of its long distance from the Earth or due to the lack of the interest of the scientific community due to non-availability of conditions to sustain human life on Neptune.

19. How hot? average surface temperature of Neptune is minus 214 degree Celsius.

20. One day on the planet: the length of a day on Neptune is 16 hours.

facts about Neptune: Gas Giant Interiors
Gas Giant Interiors. Image credit – Lunar and Planetary Institute

21. Uranus vs Neptune: Uranus is bigger than Neptune.

22. Neptune vs Earth – size comparison: it would take 60 Earth’s to completely occupy the space available on Neptune.

23. Supersonic winds: winds as fast as 1200 MPH blow on Neptune and these winds have blown away the Great Dark Spot on Neptune.

24. Wind speed comparison: Winds on Neptune can be three times faster than Jupiter’s and nine times faster than Earth’s. And scientists are amazed as to why the winds on the planet blow so fast.

25. A Monster Dark Spot: Great Dark Spot in the southern atmosphere of Neptune was first recorded by Voyager 2 in 1989. Wind speeds upward of 1500 miles per hour were recorded during this storm. However, the storm only lasted for 5 years, because when in 1994, the Hubble Space Telescope was used to view the dark Spot, the Dark Spot was not there anymore.

26. Neptune vs Earth – gravitational force: Neptune’s gravitational force is only 17% stronger than that of the Earth. Thus, Neptune is the only planet in the solar system that has Earth-like gravity.

27. Coldest of all: Neptune also has the credit of being the coldest planet in out Solar System. The temperature on the planet can get as low as minus 221 °C (The lowest natural temperature ever directly recorded at ground level on Earth is minus 89.2 °C, which was at the Soviet Vostok Station in Antarctica.)

28. Maiden orbit: since its discovery in 1946, Neptune completed its first orbit around the Sn in 2011.

29. Planet “Nine”: now a team of scientists lead by astronomer Mike Brown have announced in 2016 that they have some evidence of the existence of another planet in the solar system which they have nicknamed “planet Nine”. This planet is supposed to have 10 times the mass of Earth and an orbit which is 20 times farther than the sun on average than Neptune.

30. Latest moon: Neptune’s fourteenth (14th) moon was discovered on July 1, 2013, during a fresh analysis of the images collected by the Hubble Space Telescope. The moon was spotted nearly 150 times in the images that were collected during 2004 and 2009. Scientists estimate that the moon is just 12 miles wide. 

Quick facts/statistics about Neptune

Date of Discovery23 September 1846
Discovered byUrbain Le Verrier, John Couch Adams, Johann Galle
Orbit size around Sun4,498,396,441 km
Mean Orbit Velocity19,566 km/h
Equatorial inclination28.3 degrees
Equatorial Circumference154,704.6 km
Volume62,525,703,987,421 cubic kilometer
Mass102,410,000,000,000,000,000,000,000 kg
Density1.638 gram per centimeter cube
Surface Area7,618,272,763 kilometer square
Surface Gravity11.15 meter per second square
Escape Velocity84,816 kilometer per hour
Effective Temperature-214 °C
Atmospheric ConstituentsHydrogen, Helium, Methane
Known Moons14
Known Rings6
Largest moonTriton
Names of moonsTriton, Proteus, Naiad, Thalassa, Despina, Galatea, Larissa, Nereid, Sao, Halimede, Neso, Psmathe, Laomedeia, S/2004 N 1
Missions to NeptuneJust one: Voyager 2 in 1989.
Characteristic colorBlue