20+ Neptune Facts: Exploring the Mysteries of the Blue Planet

According to Neptune facts, the planet was discovered in 1846, more than 50 years after the next-to-last known planet, Uranus.

Urbain Le Verrier, a French mathematician, and Johann Gottfried Galle, a German astronomer, discovered Neptune. It is the only planet discovered mathematically and then spotted in the sky.

How Might A Planet Be Seen Mathematically? 

Computations of Uranus’ orbit, the last discovered planet at the time, revealed certain abnormalities and many mathematicians suggested that gravity from a nearby planet was to blame.

Le Verrier was the first to predict the new planet’s near-exact location, and he invited astronomer Galle to check his calculation by searching for the planet.

Although Pluto was discovered approximately 100 years later and was believed to be the last planet in our solar system from its discovery in 1930 until 2005, it lost its planetary status when the International Astronomical Union redefined the term “planet.”

Interesting Neptune Facts:

Neptune is our Solar System’s most distant planet:

Most Distance Planet

Neptune is approximately 4.5 billion kilometers from the Sun, which implies it is 30 times further away from the Sun than Earth.

Uranus is the nearest planet to Neptune, with an average distance of 11 astronomical units (AU; 1 AU = distance from Earth to the Sun).

Neptune had been observed numerous times before its official discovery:

Astronomers have been exploring the sky since the early 1600s better to comprehend the universe and our place in it. Galileo Galilei initially saw Neptune in 1613, although it was not recognized as a new planet then.

French astronomer Jerome Lalande is said to have seen Neptune in 1795, and John Herschel, the son of Uranus discoverer William Herschel, is said to have seen it in 1830 without understanding what he was looking at.

Neptune is 58 times the size of Earth and 17 times heavier:

Its equatorial radius is roughly four times that of Earth, bringing Neptune’s total volume and mass to nearly 63,000,000,000,000 km3 and 100,000,000,000,000,000,000,000,000 kg, respectively.

Despite being 58 times larger in volume than Earth, Neptune is only 17 times heavier due to its far lower density of 1.6 g/cm3 (Earth’s density is 5.5 g/cm3).

Neptune’s year lasts around 165 Earth years:

Neptunes Year

Because Neptune is the most distant planet from the Sun, its orbit around the Sun is 30 times longer than Earth’s, and its orbital velocity is more than five times slower, requiring 165 Earth years to complete one circle around the Sun.

This means that it takes more than 60,000 Earth days to orbit the Sun, but because days on Neptune are shorter (at 16 hours), one Neptunian year has nearly 90,000 days.

On Neptune, a 200-pound man would weigh 228 pounds:

Weight of Neptune

If you could somehow visit Neptune and find a set of scales while you were there, you might be disappointed to learn that you weighed much more than you believed.

This is because Neptune’s gravity (11.15 m/s2) is 14% greater than Earth’s. The gravitational pull of Neptune is the second largest in our solar system, after only Jupiter’s at around 25 m/s2.

Neptune is over three billion miles from Earth:

Neptunes Distance

Because both planets constantly move through the solar system, their distance also changes. The shortest distance between the two is approximately 2.7 billion miles.

At its greatest, it is approximately 2.9 billion miles, which means that light from Earth would take approximately four hours to reach Neptune. And how long would it take an Earth-bound spacecraft to reach Neptune? Depending on the path chosen, 10 to 15 years.

Neptune is named after the Roman sea god Neptune:

Neptune facts demonstrate that before it was named after the Roman deity of the sea, Neptune (corresponding to the Greek Poseidon), in December 1846, it was known (or suggested to be known) by a variety of other names, including “Le Verrier” and “Le Verrier’s planet” after the man who discovered it.

The names “the planet outside Uranus,” “Janus,” and “Oceanus” were also proposed for the solar system’s newest planet.

Thus far, only one probe has explored Neptune:

Given the huge distance between our planet and Neptune, it is hardly surprising that only one spacecraft has ever contacted Neptune in human history.

The space mission Voyager 2 sailed by Neptune in August 1989 at a distance of around 3,000 miles from its north pole, supplying us with most of the data we have about Neptune today.

After being launched from Earth, Voyager 2 took over 12 years to reach Neptune, but the probe was delayed on several occasions along the way, visiting Jupiter, Saturn, and Uranus as well.

Neptune, like other gas giants, has no solid surface:

Neptune, like the other gas giants in our solar system (Jupiter, Saturn, and Uranus), has no defined surface layer consisting of gas transitioning into a slushy water and ice layer.

The blue tint visible in images of the planet is actually the top of its clouds, not its surface. In photographs, Neptune appears as a vivid azure blue instead of Uranus’ considerably milder blue.

Neptune’s wind speed can exceed 1,300 miles per hour:

Even the most intense storm winds on Earth rarely reach 300 mph; thus, it is apparent that the high winds on Neptune would make life on Earth very impossible.

In fact, we can’t even fathom the power of these terrifying gusts. The rapid wind speeds are caused mostly by the planet’s extremely hot innards colliding with the great coldness of space.

The only large moon having a retrograde orbit is Neptune’s Triton Moon:

Neptune facts show that its largest moon, Triton, orbits the planet in the opposite direction of its rotation, making it the only massive moon in our solar system to do so.

Additionally, Triton’s orbit around Neptune is practically a perfect circle, with an eccentricity of only 0.000016 (for comparison, the Moon’s eccentricity in its orbit around Earth is 0.0549, and the Earth’s eccentricity in its orbit around the Sun is 0.0167).

Neptune’s Triton is one of the coldest places in our solar system:

Neptune facts reveal that not only is Neptune one of the coldest planets in the solar system, but its largest moon Triton is considerably colder, with temperatures on its surface reaching around – 400 °F (- 240 °C).

This massive, frozen moon is covered in explosive geysers that blast nitrogen gas several kilometers into space.

Most languages use their own version of Neptune to refer to the planet:

One of the fascinating Neptune facts is that most languages worldwide have their own version of the word “Neptune” to refer to the planet.

For example, the Chinese, who have no link to ancient European deities, refer to Neptune as the “Sea King Star,” even though Neptune is the god of the sea. The Greeks have their own version of the Roman god Neptune; they call this azure-blue planet Poseidon.

The Moons of Neptune are named after Roman and Greek water gods:

Since Neptune was named after the god of the sea, it stands to reason that its satellites are named after minor deities associated with water.

The largest moon of Neptune, Triton, is named after Poseidon (the Greek equivalent of Neptune), the moons Naiad and Nereid after two types of Greek water and sea nymphs, and Proteus, Neptune’s second largest satellite, is named after another of Poseidon’s sons.

Neptune’s only spherically shaped moon is Triton:

Neptune facts suggest that the planet’s other 12 moons are all unevenly formed, with only Triton being spherically shaped.

What distinguishes Triton from the others? Triton is unique among Neptune’s moons because the other moons’ surfaces are all too small to have collapsed into a spheroid.

Neptune is Pisces’ ruling planet and is exalted in Leo:

Neptune is a sign of sensitivity, idealism, compassion, and occasionally illusion, deception, or confusion for those who believe in the art of astrology. It represents materiality piercing the spirit.

Neptune, often known as the Planet of Illusion, is seen as extremely essential by many astrological practitioners. It is thought to help eliminate obstacles and boost people to the level of experiencing mystical events.

Neptune’s orbit is occasionally closer to the Sun than Pluto’s:

Pluto is currently regarded as a dwarf planet; thus, there is no debate about which planet is in the farthest reaches of our solar system.

Even when Pluto was still regarded as a planet, Neptune held the position of 9th planet in our solar system on occasion, simply because it orbits the Sun farther away than Pluto does (the last time this occurred was between the years of 1979 and 1999).

Neptune has an unknown internal heat source:

Neptune receives just around 0.1% of the solar energy that reaches the Earth since it is 30 astronomical units (1 AU = distance of Earth from the Sun).

However, it emits 2.6 times more energy than it receives from the Sun, indicating that it has its own internal heat source. Regrettably, we still have no idea what this is, where it is, or how it generates so much heat.

Neptune had a storm large enough to cover the entire planet:


Neptune’s facts reveal that Neptune was previously destroyed by a massive storm capable of covering the entire Earth’s surface. When Voyager 2 visited Neptune in 1989, it discovered a massive storm moving westward at 750 mph in the southern hemisphere.

When scientists used the Hubble Space Telescope to picture the storm, dubbed Great Dark Spot, again in 1994, it had vanished, but a similar storm had emerged in the northern hemisphere.

Neptune is our solar system’s farthest planet from the Sun, the third largest planet by mass and the fourth largest by diameter.

Neptune Facts
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