Fun Facts About Neptune

Fun Facts About Neptune: all 30, explained

1. Neptune has the fastest winds in the solar system.

   Winds on Neptune have been measured at around 2,000 km/h, faster than the speed of sound on Earth, even though the planet is far from the Sun’s heat.

   Source: Neptune (Wikipedia) · Fact card

2. Neptune was found by maths before anyone saw it.

   Astronomers noticed Uranus was being tugged off course and calculated where an unseen planet must be. In 1846, Johann Galle pointed a telescope at the predicted spot and found Neptune.

   Source: Neptune (Wikipedia) · Fact card

3. Neptune completed its first full orbit since its discovery only in 2011.

   Neptune takes about 165 Earth years to go around the Sun. It was discovered in 1846, so it did not return to the same spot until 2011.

   Source: Neptune (Wikipedia) · Fact card

4. Neptune is the eighth and farthest planet from the Sun.

   It orbits about 4.5 billion kilometers from the Sun, around 30 times farther than Earth.

   Source: Neptune (Wikipedia) · Fact card

5. A year on Neptune lasts about 165 Earth years.

   It has completed just one orbit since it was discovered in 1846.

   Source: Neptune (Wikipedia) · Fact card

6. A day on Neptune lasts about 16 hours.

   Like the other giant planets, it spins much faster than Earth.

   Source: Neptune (Wikipedia) · Fact card

7. Neptune is an "ice giant".

   Below its atmosphere it is made largely of water, ammonia and methane in hot, dense forms rather than gas.

   Source: Ice giant (Wikipedia) · Fact card

8. Methane helps make Neptune blue.

   Methane in the atmosphere absorbs red light and reflects blue.

   Source: Neptune (Wikipedia) · Fact card

9. Neptune is about four times as wide as Earth.

   It is about 17 times as massive as Earth.

   Source: Neptune (Wikipedia) · Fact card

10. Neptune was first seen through a telescope in 1846.

    Johann Galle spotted it in Berlin using predictions by Urbain Le Verrier, based on wobbles in Uranus’s orbit.

    Source: Discovery of Neptune (Wikipedia) · Fact card

11. Galileo saw Neptune in 1612 but thought it was a star.

    His notes show he recorded it but did not realize it was a planet.

    Source: Discovery of Neptune (Wikipedia) · Fact card

12. Only one spacecraft has ever visited Neptune.

    Voyager 2 flew past in August 1989 and sent back the first close-up images.

    Source: Voyager 2 (Wikipedia) · Fact card

13. Neptune had a storm as big as Earth, the Great Dark Spot.

    Voyager 2 photographed it in 1989; by 1994 the Hubble Space Telescope found it had disappeared.

    Source: Great Dark Spot (Wikipedia) · Fact card

14. Neptune’s largest moon, Triton, orbits backward.

    Triton circles opposite to Neptune’s spin, a sign it was probably captured from the Kuiper Belt.

    Source: Triton (moon) (Wikipedia) · Fact card

15. Triton has geysers of nitrogen.

    Voyager 2 saw dark plumes rising several kilometers above its frozen surface.

    Source: Triton (moon) (Wikipedia) · Fact card

16. Triton is one of the coldest places measured in the solar system.

    Its surface is about minus 235°C.

    Source: Triton (moon) (Wikipedia) · Fact card

17. Triton is slowly spiraling toward Neptune.

    In billions of years it may be torn apart and form a ring.

    Source: Triton (moon) (Wikipedia) · Fact card

18. Neptune has 16 known moons.

    Triton holds more than 99% of the mass of all of them combined.

    Source: Moons of Neptune (Wikipedia) · Fact card

19. Neptune has dark, faint rings.

    The rings are named after astronomers linked to its discovery, including Galle, Le Verrier and Adams.

    Source: Rings of Neptune (Wikipedia) · Fact card

20. Neptune’s outer ring has clumps named Liberty, Equality and Fraternity.

    The arcs in the Adams ring carry the French revolutionary motto, in French: Liberté, Égalité and Fraternité.

    Source: Rings of Neptune (Wikipedia) · Fact card

21. Neptune gives off more than twice the heat it gets from the Sun.

    Its internal heat source may drive its extreme winds.

    Source: Neptune (Wikipedia) · Fact card

22. Neptune has seasons that last about 40 years each.

    Its axis is tilted about 28 degrees, similar to Earth’s, and its year is 165 Earth years long.

    Source: Neptune (Wikipedia) · Fact card

23. Neptune is named after the Roman god of the sea.

    Its astronomical symbol is a trident.

    Source: Neptune (mythology) (Wikipedia) · Fact card

24. Neptune became the farthest planet again in 2006.

    When Pluto was reclassified as a dwarf planet, Neptune became the outermost planet.

    Source: Pluto (Wikipedia) · Fact card

25. Pluto is sometimes closer to the Sun than Neptune.

    Pluto’s oval orbit crossed inside Neptune’s from 1979 to 1999, but the two never collide.

    Source: Pluto (Wikipedia) · Fact card

26. It may rain diamonds inside Neptune.

    Lab experiments suggest the pressure deep inside ice giants could turn carbon into diamonds that sink toward the core.

    Source: Neptune (Wikipedia) · Fact card

27. Gravity at Neptune’s cloud tops is a little stronger than Earth’s.

    It is about 1.1 times Earth’s gravity.

    Source: Neptune (Wikipedia) · Fact card

28. Sunlight takes about four hours to reach Neptune.

    From Neptune, the Sun looks like a very bright star.

    Source: Neptune (Wikipedia) · Fact card

29. Neptune has its own Trojan asteroids.

    Small bodies share its orbit, gathered ahead of and behind the planet.

    Source: Neptune trojan (Wikipedia) · Fact card

30. Neptune’s moon Nereid has one of the most stretched-out orbits of any moon.

    Its distance from Neptune varies enormously during each orbit.

    Source: Nereid (moon) (Wikipedia) · Fact card