Kid facts about Neptune

Kid facts about NeptuneIt’s the eighth planet from the sun making it the farthest in the solar system. There are many things that people don’t know about Neptune. It’s time that you give your undivided attention to Neptune because like other planets, it’s a gas giant that’s full of wonder.

Here are the most amazing kid facts about Neptune:

Planet profile in numbers

Aside from being the eighth planet in the solar system, Neptune is also considered the fourth largest planet by diameter, next to Earth. The largest planet by diameter is Jupiter followed by Saturn and Uranus. In terms of mass, it’s the third massive planet. As a matter of fact, Neptune is 17 times Earth’s mass; it’s also considered the densest of all giant planets.

Kid facts about Neptune

It has an equatorial diameter of 49,528 kilometers and a polar diameter of 48,682 kilometers. It has 14 moons and 5 rings. Its orbit distance is 4,498,396,442 kilometers. It orbits for 60,190 days roughly 164.8 Earth years. Its temperature is -214°C. Urbain Le Verrier and Johann Galle discovered it on September 23, 1846.

The controversy behind the discovery

The controversy behind the discovery
Controversy of Neptune

Back in the day, people loved stargazing. With the invention of the telescope, people began to wonder what is beyond the horizon. Surely, there was something more than the stars, constellations and the moon. In 1612, Galileo used a small telescope to plot the points of a fixed star which was believed to be Neptune. In 1812, Alexis Bouvard published an orbital table of Uranus. Kid facts about Neptune state that, at the time, he discovered some deviations from the tables that theorized an unknown celestial body disturbing the orbit of Uranus. John Couch Adams continued to study Uranus’ orbit from 1843 to 1846.

Adams generated different calculations of a new planet with the support from the director of Cambridge Observatory James Challis and Astronomer Royal George Airy. Between 1845 and 1846, Urbain Le Verrier created his own calculations but it was tough because he did not get any support from his compatriots. When Adams and Le Verrier published their calculations, Airy noted the similarities, thereby, urging Challis to search for the planet.


During this time, Le Verrier found a way to search for the planet. He wrote a letter to the Berlin Observatory through Johann Galle to search for the planet using a refractor. Kid facts about Neptune– Finally on September 23, 1846, when the two discovered Neptune Challis also realized that he had already observed the planet twice.

The origin of the name

It was on December 29, 1846, that the international community accepted Neptune as a name for the planet. In Roman mythology, Neptune is the God of the sea. There was a trend to naming planets based on Roman and Greek deities. In fact, only Earth was not named after a deity. Other cultures didn’t adapt to Neptune right away. Some cultures used a different variant of Neptune. For example, Mongolians called Neptune “Dalain Can”, who was the Mongolian ruler of the sea. In Hebrew, they called Neptune “Rahab”, a biblical sea monster. In Maori, Neptune was called “Tangaroa”, the Maori God of the sea.

Physical characteristics:

Physical Characteristics of Neptune
Structure of Neptune

Kid facts about Neptune mention that Neptune is an ice giant like Uranus, Jupiter, and Saturn. The internal structure of Neptune is similar to Uranus (check out the interesting facts discussed in the article “Kid Facts About Uranus“). The interior portion of the planet is composed of upper atmosphere-mostly clouds, an atmosphere comprised of methane, hydrogen and helium gas, a mantle composed of water, methane ice and ammonia, and a core comprised of rock.

The atmosphere around Neptune is 80% hydrogen and 19% helium, the remaining is composed of trace amounts of methane. Like Uranus, the methane is why Neptune has a blue shade. The difference is Neptune has a vivid blue while Uranus has a milder cyan. The atmosphere of the planet is divided into two regions – troposphere and stratosphere. In terms of the magnetic field, the planet is similar to Uranus because it’s tilted at 47°.

The climate:

The climate
Weather on Neptune

Kid facts about Neptune talk about the weather on Neptune, it’s inhabited by dynamic storms. The winds on the planet can reach up to 2,200 kilometers per hour. Researchers found that the winds on the planet can move in opposite directions. There was also an abundance of methane, acetylene, and ethane at the planet’s equator. Due to the long orbit period, scientists believe that the seasons there last up to forty years.

The orbit and rotation

You already know that it takes 164.79 years for Neptune to complete an orbit. Since its discovery, it has completed its first full orbit on July 11, 2011. The axial tilt of the planet is 28.32° is the same as Mars (having 25°) and Earth (having 23°). From Kid facts about Neptune, we know that due to the axial tilt, Neptune endures the same seasonal changes as Earth, but because of its long orbit period, the seasons last for 40 Earth years.

The Neptunian moons

Presently, there are 14 known moons; the largest moon is called Triton. William Lassell discovered Triton; in 1989, Triton was the coldest object in the solar system. After Triton, another moon was discovered called Nereid. In 1989, another moon was discovered called Proteus. This moon is known to be the second most massive moon around Neptune. Other planets include Naiad, Thalassa, Despina, Galatea, and Larissa. Between 2002 and 2003, there were 5 irregular moons discovered. The newest and smallest moon is called S/2004 N 1.

Rings of Neptune

Rings of Neptune
Neptune with Rings

Kid facts about Neptune state that it has a system of planetary rings just like Uranus as mentioned in the facts of Uranus for Kids. The research concluded that the rings occurred from ice particles enveloped in carbon-based materials. This is the reason why the rings have a reddish hue. The three main rings are Adams Ring, Le Verrier Ring, and Galle Ring. At the time of observation, researchers also saw a faint ring extension of the Le Verrier Ring. It’s called Lassell, Arago Ring is also a part of the ring collection around the planet.

Adams Ring is comprised of five dominant arcs called Courage, Liberte (Liberty), Egalite 1 (Equality 1), Egalite 2 (Equality 2) and Fraternity (Fraternity).  In 2005, experts theorized that Neptune’s rings were unstable. There were images from the W.M Keck Observatory that illustrated significant decay within the rings; this wasn’t the case during the Voyager 2 flyby.


Due to its distance from Earth, Neptune is not visible to the naked eye. Kid facts about Neptune- It’s outshined by Jupiter’s moons, the dwarf planet Ceres, and asteroids (4 Vesta, 2 Pallas, 7 Iris, 6 Hebe, and 3 Juno). You can see it if you have a powerful telescope. Neptune will appear as a small blue-disk, which is similar to Uranus’ appearance.


Study of Neptune

Till date, only the Voyager 2 has visited Neptune, on August 25, 1989. There’s no doubt that only one spacecraft has visited the planet because of its distance. The visit was actually brief and took 246 minutes for the signal to reach Earth. The spacecraft had a close encounter with Nereid before entering Neptune’s atmosphere; it also passed Triton on the same day. The spacecraft validated the existence of a magnetic field. Kid facts about Neptune- After Voyager 2, there will be more flyby missions arranged for the future, but it will take many years to complete the trip. For now, in 2019, Argo is going to be launched. Argo is a flyby spacecraft that will visit Jupiter, Saturn, Neptune, and a specific Kuper belt object.

Other fun facts:

You already know that Neptune is an ice giant. What you don’t know is that it’s the smallest ice giants. As compared to Uranus, Neptune is smaller in diameter but it has a greater mass. Like Jupiter, Neptune has dark spots. Dark spots are a phenomenon in areas that have a high atmospheric pressure. The pressure forces clouds of methane gas to rise into the atmosphere. On Earth, it’s called a cirrus cloud. The dark spots disappear and then reappear on different parts of Neptune, unlike the spots on Jupiter. The largest storm ever recorded was in 1989 and was called The Great Dark Spot as it lasted for 5 years.


There are many kid facts about Neptune that you should know about. It will surely quench your thirst for whatever is beyond our starry skies. It pays to be aware and it’s fascinating to know that there are other planets in our solar system with different characteristics. It’s just a shame that you can’t visit them. Well, you can always observe them through a real telescope.


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