12 Interesting Facts About Neptune: What the Ancients Didn’t Know

27th Dec 2022
12 Interesting Facts About Neptune: What the Ancients Didn’t Know

People have been interested in the starry sky since time immemorial, but they began to discover other planets in the solar system only in the 17th century, with the invention of the first telescopes. Neptune is the eighth and farthest planet from the Sun, and our knowledge of it is comparatively low. The planet is located too far from Earth, so manned expeditions to Neptune are not yet planned. But scientists have uncovered some information about it. Here, we list some interesting facts about Neptune, which should give you an idea of this amazing and mysterious planet.

What is Neptune Best Known For

A research probe has been sent to Neptune’s surrounding area only once. In 1989, 12 years after the launch from Earth, one of the American Voyager ships approached and circled Neptune only once. The device passed three thousand kilometres from the pole, but scientists received data that we will gladly share with you.

Who and when discovered Neptune

Neptune was first “seen” through a telescope by Galileo Galilei in 1612, but he failed to recognize it as a planet. Since Neptune was at a fixed point during this observation period, its movement was minuscule, and Galileo mistook it for a star. The thing is, consistent observation of such a distant object requires a telescope with at least 200x magnification. For a long time, scientists did not have such equipment, so they used a mathematical analysis of astronomical observations to discover this celestial body. This is a unique case in history and one of the most interesting facts about Neptune.

Who used mathematical calculations to discover the planet Neptune?

Urbain Le Verrier
Urbain Le Verrier

In the early 19th century, scientists were puzzled by anomalies in the orbit of Uranus and suggested that the influence of some large celestial body caused them. The French mathematician Urbain Le Verrier made mathematical calculations and convinced the German astronomer Johann Galle to start looking for this body. So on September 24, 1846, the new planet was discovered at the Berlin Observatory, which was named after the ancient Roman god of the seas and streams — Neptune. The method used in its discovery also gave Neptune its middle name — the mathematician’s planet.

Gas Giant

Neptune is the smallest and densest of the four gas giants in our solar system. It is located at a distance of about 4.5 billion km from the Earth (about 30 times farther from the Sun than we are). The equatorial radius is almost four times greater than the Earth’s (about 24.7 thousand km), the mass is seventeen times, the magnetic field is 27 times, and gravity is 17% higher. The planet’s rotation speed is almost twice that of Earth’s. The atmosphere consists mainly of hydrogen, helium, a small amount of ethane, hydrogen deuteride, and possibly, nitrogen.

A day on this planet lasts only 16 Earth hours (the period of rotation around its own axis), the seasons are forty Earth years, and a year (a full revolution around the Sun) is almost 165 Earth years. Among interesting facts about the Neptune, it is worth noting that it has 14 satellites and is also the only giant planet where the shadow of upper clouds are visible on the lower cloud layers.

Neptune is Blue

Why is neptune blue
Why is Neptune blue?

If you observe Neptune through a powerful telescope, it will appear bright blue. Astronomers believe that this colour comes from methane, which absorbs short-wave red light well and reflects long-wave light. One possible answer to the question of Why is Neptune blue is that its icy clouds may include other gases or some completely unknown components. What we do know for sure is that this colour does not come from water. Water is available in very scarce amounts on Neptune.

Cold outside, hot inside

Due to the high proportion of ice on the surface, this planet is often called the “ice giant”. However, one of the most interesting facts about Neptune is that it heats up from the inside. The temperature in the upper layers of the atmosphere is close to -220 °C, but reactions occur in the centre that heat its core up to 7000 °C. That is why Neptune radiates 2.6 times more heat than it receives from the outside.

Scientists have not been able to explain this phenomenon yet. Possibly, the heating results from the interaction of the atmosphere with ions moving in the planet’s magnetic field or is a consequence of gravitational waves from the inner regions.

Neptune has 6 rings

Neptune rings

Neptune has six rings made up of frozen water and carbon. Since they are not very dense, they were only discovered in the mid-1980s. Scientists believe that these are the remains of an exploded satellite. There is an assumption that these rings are composed of dust and organic compounds formed under the influence of sunlight.

Almost liquid

Gas planets do not have solid surfaces. Scientists believe that Neptune is an icy gaseous ball with a solid core (made of nickel iron and silicates), the pressure in which can reach 7 Mbar. Below the upper layers of the atmosphere, gases condense and turn into a superheated liquid ocean with temperatures up to 200-5000 K. The total mass of this area can be 10-15 Earth masses. Very high-pressure Earth experiments show that Neptune’s upper mantle could very well be an ocean of liquid carbon.

Raining diamonds


neptune raining dimonds

The planet’s core is covered with methane heated to 4700°C, and the pressure in the bowels at a depth of 10 thousand km can reach tens of thousands of atmospheres! This brings up the question of the possibility of converting hydrocarbons into diamonds. So, do diamonds really rain on Neptune?

Using a super-powerful X-ray laser, the researchers were able to simulate “diamond showers” in real-time. It turns out that under high pressure and temperatures, methane molecules break apart, releasing carbon, which forms crystalline patterns. Later, these diamond-like structures penetrate the layers of the heated mantle (up to 6,000°C), evaporate and rise up, so the cycle repeats again and again. Such an effect can be compared with rain. This one is most definitely in our Top 3 awesome facts about Neptune.

Giant hurricane spots

Giant hurricane spots on Neptune

Scientists have noticed “dark spots” on the surface of the planet that appear as quickly as they disappear. Observation and study have shown that this is the shape of a huge storm system. This is what cyclones look like on Earth. On Neptune, however they are much more powerful.

Using the Hubble telescope, it was discovered that spots regularly appear at low altitudes of the troposphere and disappear about once every two years. The mechanism of the phenomenon is yet to be explained.

Very windy

Voyager managed to detect a hurricane in the planet’s atmosphere with wind gusts up to 600 m/s. As a rule, at low latitudes, winds blow in the opposite direction of Neptune’s own rotation. So far, scientists cannot accurately determine the cause of this phenomenon. The only assumption is a surface effect — that is, such a wind can generate low friction cold fluid flows on the surface.

Neptune wasn’t always where it is now

Among other interesting facts about Neptune, it is worth mentioning that the planet has not always been in the orbit where it is now. Scientists believe that it could have formed closer to the Sun and then was forced into a larger orbit by the gravitational field of Jupiter.

You can’t survive on Neptune

There is nothing on Neptune that could guarantee us even the slightest chance for survival — no heat, oxygen, or water. Even for bacterial life to arise, a source of energy and liquid water is required. It is cold on the planet’s surface (the temperature is only 55 K), so assuming can life survive on Neptune is out of the question. At best, this could be possible somewhere at a depth of several kilometers. But such a possibility is still shrouded in mystery.

What would happen if Neptune exploded

Scientists believe the disappearance of Neptune would likely not affect the Earth. It is too far to cause us any harm. Neighboring Pluto will most likely be affected, while Uranus may change its orbit a little closer to Saturn; the rest of the planets should not be affected, though. However, the fact that Neptune is at the very edge of the solar system raises another danger. Scientists simulated a situation in which Neptune could be affected by a neighbouring star that came close enough to our Solar System. The simulations suggest that a passing star only needs to change Neptune’s orbit by 0.1%, a distance three times the distance between the Earth and the Sun, for all the planets in the Solar System to descend into chaos. Fortunately, this probability is extremely small, so we hardly need to worry about it.

Final Thoughts

Now that you have learned the 12 most interesting facts about Neptune, you probably have new questions in mind. You’re not alone in this!

So far, our technology is underdeveloped for exploring Neptune up close. The weather on this planet is absolutely terrible, and there is no oxygen or solid surface. We can’t even land on it, so we will have to rely on powerful telescopes and robotic missions to learn any new information about this planet.

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