Neptune Facts
NEPTUNE FACTS
The home of interesting Neptune facts for kids and adults.
The Planet Neptune Factfile
| Neptune | |
|---|---|
| Position from the Sun | 8 |
| Diameter | 49,528 km |
| What is the mass? | 17 Earth |
| How many moons? | 14 |
| How far long is the orbit distance? | 4,498,396,441 km |
| How long does it take to orbit the sun? | 60,190 days |
| Whats the temperature on Neptune? | -201 °C |
| When was Neptune discovered? | September 23, 1846 |
| Who first discovered Neptune? | John Couch Adams, Urbain Le Verrrier and Johanne Gottfried Galle |
10 Facts about Neptune you didn't know.
1. Neptune was discovered by Mathematical calculations.
The first person to have observed Neptune was Galileo Galilei, who marked it as a star in one of his drawings. Since he did not identify it as a planet, he is not solely credited with Neptune's discovery. For 200 years or more, Neptune lay hidden within the network of stars in Galileo's drawings.
In September 23, 1846, two mathematicians named Frenchman Urbain Le Verrier and British man John Couch Adams predicted that a new planet - then named "Planet X" would be discovered in a specific region of the sky.
Astronomer, Johanne Gottfried Galle from Germany used Le Verrier's calculations to find Neptune.
Did you know?
Both Great Britain and France lay claim to the planets Discovery. This dispute was amplified by existing political tensions between Great Britain and France at the time. Today, all three are credited with Neptune's discovery.
2. Neptune is the densest gas giant in the solar system.
Neptune is approximately 17 times the mass of Earth, but is also 4 times the larger than Earth. Neptune's mass is spread out over a larger volume. Its average density is 1.6 gm/cm3.
This makes Neptune approximately:
19% more dense than Jupiter and Uranus. (1.3 gm/cm3)
57% more dense than Saturn. (0.7 gm/cm3)
Did you know?
Gravity on Neptune is the closest to Earths. Neptune's gravity is approximately 17% stronger than Earth's gravity (one g).
3. Neptune is the furthest planet from the sun.
Neptune was classed as the most distant planet in the solar system up until 1930 when Pluto was discovered. Neptune then became the 2nd most distant planet in the solar system. In 2006, Pluto was reclassified as a dwarf planet and Neptune secured its original title again.
Did you know?
Between 1979 and 1999, Pluto's elliptical, egg shaped orbit, brought Pluto closer to the sun than Neptune. For that 20 year period, the title of most distant planet was incorrect.
4. Only one spacecraft has visited Neptune.
The Voyager 2 flew by the planet on August 25, 1989 and remains the only spacecraft to visit Neptune. It remains in operation to this day and has been operating for over 43 years.
Did you know?
There have been two cancelled space missions to Neptune.
- Neptune orbiter - 2016
- Argo - 2019
The next mission concept is Odinus that would launch in 2034.
5. Neptune is the coldest planet in the solar system.
Temperatures on Neptune can reach -221.45 °C, that's nearly 3 times colder than the coldest temperatures ever recorded on Earth at -89.2°C.
Did you know?
Neptune gained the title as the coldest planet in the solar system when Pluto was reclassified as a dwarf planet in 2006.
Neptune is the smallest of the gas giants.
Neptune is the smallest of the 4 gas giants in terms of diameter, however, takes the third place ahead of Uranus in terms of Mass and is 17 times as massive as Earth.
Did you know?
Although Neptune is the smallest of the Gas Giants, the average diameter across the planet is 4 times the diameter of Earth.
7. Neptune's winds are the fastest in the solar system.
Winds on Neptune have been known to reach up to 1,500 mph or 2,414 km per hour. Neptune's most famous storm named the Great Dark Spot was first observed in 1982 by the Voyager 2 spacecraft. It was approximately the size of Earth and reached 1,500 mph.
Five years later, the Hubble Space telescope found that it had disappeared yet another smaller storm had appeared in the northern hemisphere. This storm was the size of Earth's moon and was named the Small Dark Spot.
Did you know?
Winds on Neptune are up to 4.71 times stronger than Earths most damaging tornados.
A tornado on Earth is measured by the Fujita scale. Tornadoes are measured on a scale of F0-5, F5 being classed as an Incredible Tornado.
F5 tornados reach between 261 and 318 Mph. The damage can be catastrophic as strong frame houses lifted off foundations and carried considerable distances to disintegrate; automobile sized missiles fly through the air in excess of 100 meters; trees debarked; steel re-enforced concrete structures badly damaged.
8. Neptune has 5 main rings.
Neptune has 5 faint main rings. The 3 main rings are named after the three people who discovered Neptune. The Adams ring, the Le Verrier ring and Galle ring.
Neptune also has 4 ring arcs. These have gaps and do not constitute a full ring. These are named Courage, Liberté, Egalité 1, Egalité 2 and Fraternité (Courage, Liberty, Equality and Fraternity).
Did you know?
Astronomers once believed that the matter within the ring arcs would spread out over time. However, they now believe that the arcs are controlled by the gravitational effects of Neptune's moon Galatea.
More recent Earth based observations have shown that the ring arcs may decay and predict that the Liberté arc may disappear in as little as one century.
9. Neptune is named after the Roman god of the sea.
In Roman mythology, Neptune was the god of the sea. In ancient Greek it is identified with Poseidon. Modern Greek's still call the planet Poseidon till this day.
Did you know?
Neptune has had many names. Originally, during prediction it was labelled as "planet x". After discovery each of the astronomers simply called it "the planet exterior to Uranus" proposed suggested names. These included Oceanus, Janus and Neptune.
In October that year, he sought to name the planet after himself.
By December 29, 1846 other astronomers and nations became involved. Soon after, Neptune became the internationally accepted name.
10. Neptune has 14 moons.
Neptune currently has 14 moons. Triton is the largest of the moons and only one that is spherical in shape. Scientists believe that Triton was in-fact a dwarf planet that was captured by Neptune's gravitational pull. It is the only moon in the solar system that orbits in the opposite direction to the planet and is also the coldest known object in the solar system.
Did you know?
Neptune's known moons are named after sea gods and nymphs in Greek mythology. They are: Triton, Thalassa, Naiad, Nereid, Proteus, Neso, Despina, Hippocamp, Galata, Halimede, Psamathe, Laomedeia, Larissa and Sao