Neptune has more mass than its nearest gas giant neighbor, Uranus. However, Neptune is physically smaller than Uranus because its group also makes it very dense. In addition, Neptune’s gravity squeezes the planet’s atmosphere, so it fits more mass into a smaller space.
Neptune orbits the Sun once every 164.8 years, meaning one Neptunian year is nearly 165 times longer than an Earth year. On the other hand, Neptune rotates once every 16 hours, so a day on Neptune is 8 hours shorter than Earth’s.
Which is the planet farthest from the Sun?
Neptune is the farthest planet from the Sun! However, there are several dwarf planets, the most notable of which is Pluto. This is why people sometimes get confused and think Pluto is the farthest planet from the Sun. Pluto’s orbit is much more elongated than those of the other planets. This means it is closer to the Sun for 20 years of Pluto’s 249-year orbit than Neptune. There are dwarf planets beyond Pluto, also. Currently, the farthest dwarf planet from the Sun is called Eris.
90377 Sedna, also known as just Sedna, is a large planetoid in the solar system’s outer reaches. Sedna is currently recognized as a potential dwarf planet. Scientists have estimated that it takes over 11,000 years for Sedna to orbit the sun.
Neptune’s distance from the Sun
As previously mentioned, Neptune is the furthest planet from the Sun, but how far is it? Neptune’s distance from the Sun is approximately 2.8 billion miles or 4.5 billion kilometers. Another way of looking at this is that Neptune is a distance of 30 astronomical units away from the Sun. To put this into perspective, the Earth is one astronomical unit away from the Sun. Due to the sheer size of Neptune’s distance from the Sun, it takes sunlight a whopping 4 hours to travel from the Sun to the planet.
Neptune’s Stats
Formation
Neptune formed along with the rest of the solar system around 4.5 billion years ago. At this time, gravity pulled together a bunch of gas and dust to form the vast planet that we now call Neptune. Like Uranus, Neptune is believed to have originated closer to the Sun but moved to the outer solar system around 4 billion years ago.
Structure
Neptune is one of two substantial ice giants in the outer solar system. The other ice giant is Neptune’s neighbor, Uranus. So, what is Neptune made of that makes it an ice giant?
Neptune primarily consists of a hot dense fluid of ‘icy’ materials, including water, methane, and ammonia. These are positioned above a small, rocky core. Neptune has a rank structure out of all the giant planets in the solar system.
Fun Fact: Scientists believe that Neptune may have its ocean. This ocean is made of boiling water and is located beneath Neptune’s cold clouds. The sea does not boil away due to the high pressure that keeps it trapped inside.
Surface
While we may think of planets as solid bodies, this is not always the case. Neptune, for instance, does not have a solid surface. Instead, its atmosphere, consisting mainly of hydrogen, helium, and methane, stretched deep into the planet. As a result, the atmosphere gradually merges into the water and other melted ice over the solid, rocky core of the world, with pretty much the same mass as Earth.
Atmosphere
As briefly mentioned above, the atmosphere on Neptune is made up primarily of hydrogen and helium, with a hint of methane. As a result, Uranus, positioned next to Neptune in the solar system, has a distinct blue-green color due to the methane in its atmosphere. However, even though Neptune’s atmosphere also contains methane, it has a very different color. Neptune is, instead, a much more vivid blue color. This has led scientists to conclude that there must be an unknown component of Neptune’s atmosphere that causes its vibrant color.
Interestingly, Neptune is the windiest planet in our solar system. Despite Neptune’s distance from the Sun and general low energy input from the Sun, Neptune’s wind is super strong. The wind on Neptune can get up to three times stronger than Jupiter’s and a whopping nine times more potent than Earth’s wind. These insanely windy conditions sweep clouds of frozen methane across the planet at over 1,200 miles (2,000 kilometers) per hour. To put this into perspective, the most powerful wind on Earth would only be able to reach a speed of around 250 miles (400 kilometers) per hour.
Much like the Great Red Spot found on Jupiter, Neptune has its storm, which has been called the Great Dark Spot. This storm, which is oval and discovered not that long ago in 1989, is so massive that it could contain the entirety of Earth. The storm, located initially in Neptune’s Southern Hemisphere, has since disappeared, but the planet is not storm-free as various new ones have appeared in different areas.
Potential for life
The one question that people always want to know when discussing the solar system is, ‘Could there be life on other planets?’ For some of the planets in our solar system, the atmosphere is such that humans could survive there, although they might be a bit uncomfortable. Neptune, however, is not one of these planets.
As far as we know, Neptune’s environment is incompatible with human life. This results from various factors, including the planet’s temperature, pressure, and materials. These features of Neptune would be much too extreme and volatile for humans to adapt to, making human life impossible on earth.
The Pluto problem
Since its discovery in 1930, Pluto has been regarded as one of the planets in our Solar System. However, in 2006, this all changed. The International Astronomical Union altered its definition of a planet; consequently, Pluto’s status was demoted to that of a dwarf planet. This gave way to Neptune becoming the farthest planet from the Sun.
Pluto’s orbit
It would be reasonable to assume that Pluto was the farthest planet from the Sun for the 76 years between its discovery and its demotion to a dwarf planet. However, a unique aspect of Pluto’s orbit meant this wasn’t the case.
On the 21st of January 1979, Pluto moved inside Neptune’s orbit, officially making Neptune the farthest planet from the Sun. Then, in February 1999, Pluto moved again beyond Neptune’s orbit. This meant that Pluto, then, became the most distant planet from the Sun. Pluto crosses this line, moving in and out of Neptune’s orbit for 20 years out of its 249-year-long revolution around the Sun. Pluto’s strange movement in the Solar System is its elliptical orbit. This orbit takes Pluto closer to the Sun than Neptune for 20 years out of its revolution around the Sun. This means that, at its closest distance to the Sun, Pluto is more intimate than Neptune.
Periodic comets
Planets are not the only thing in our Solar System; there is a range of other objects in space, including periodic comets. Likewise, there are lots of periodic comets that are known to have orbits within the planetary system. The most famous of these is probably Halley’s comet.
Where do comets come from?
Astronomers theorize that there is a belt of icy objects beyond Neptune, where several dark comets orbit the Sun in the realm of Pluto. From time to time, gravity pushes these objects into orbits, which brings them closer to the Sun. These become what are known as short-period comets. These comets take under 200 years to orbit around the Sun and are much more predictable than long-period comets. Many long-period comets come from the Oort Cloud, a cloud of millions of objects in circular orbits around the Sun. These long-period Oort Cloud comets take much longer to orbit the Sun than short-period comets. Long-period comets can take up to 30 million years to complete just one revolution around the Sun.
What is a comet?
Each comet contains something called a nucleus. This nucleus is a small, frozen section in a comet, typically just a few kilometers long. Inside the nucleus are icy chunks and frozen gases, which are embedded with pieces of dust.
Something interesting about comets is that they get warmer as they get closer to the Sun and also develop an atmosphere. The heat of the Sun is enough to cause the ice within comets to change into gases. This causes the atmosphere to grow in size. As a result, a comet’s atmosphere can reach enormous heights, spanning hundreds of thousands of kilometers. What’s more, the pressure of the sunlight and high-speed solar particles can blow the dust and gas from the comet’s atmosphere away from the Sun. This process can cause a comet’s signature ‘tail’ to form. In reality, comets have two tails, a dust tail, and a gas tail.
The majority of comets travel at a safe distance from the Sun. However, there are several comets, widely known as sungrazers, that crash directly into the Sun or get so close that they break apart and evaporate.
Does Neptune have rings?
Neptune does have a ring system, but it is not as visible as the rings of Saturn. Neptune has six rings made of ice particles; some are reddish. The rings were first discovered in 1968, and the Voyager 2 probe took pictures of them when it passed Neptune on its journey to the edge of the Solar System. Unfortunately, Neptune’s rings seem more unstable than Saturn’s rings, and it is thought that they may eventually disappear.
Does Neptune have any moons?
Neptune has 14 moons, but many are small and not spherical. The largest moon of Neptune is Triton, which is the only one that is a sphere. The rest are all small asteroid-like moons, some of which orbit within Neptune’s rings.
Triton is the only moon in the Solar System that orbits its parent planet in the opposite direction to the planet’s spin. This is known as a ‘retrograde’ orbit. This fact has led scientists to believe that Triton was not formed with Neptune and was caught in its orbit.
When was Neptune discovered?
Technically, the astronomer, Galileo, is responsible for the discovery of Neptune. Some of the earliest-ever recorded observations made through a telescope belong to Galileo. These observations, recorded between the end of 1612 and the beginning of 1613, have been found to show records of the planet Neptune. While he recorded it, Galileo did not know it was a planet at the time. Instead, he is believed to have mistaken it for a fixed star. For this reason, he is not officially recognized as the person who discovered Neptune.
It was not until 1821 that French astronomer Alexis Bouvard first hinted at the existence of another planet beyond Uranus, as he published his records of Uranus’ orbit that showed an unusual movement that suggested that there was another planet even further away.
A British astronomer John Couch Adams studied Bouvard’s work and estimated that the other planet was affecting Uranus’ orbit. Then, using only mathematics, another French astronomer called Urbain Le Verrier predicted the location of Neptune.
The actual discovery of Neptune, then, is accredited to Urbain Le Verrier, John Couch Adams, and Johann Galle in September 1846.
At first, Le Verrier wanted to name the planet Le Verrier after himself. Finally, however, the planet was named Neptune, after the Roman god of the sea. This was in keeping with the names of all the other planets in the Solar System, which are named after Greek or Roman gods.
Is Neptune’s gravity the same as Earth’s gravity?
Neptune’s gravity is 110% of the gravity on Earth. This means that something that weighs 10 kg on Earth will weigh 11 kg on Neptune. Even though Neptune is so much larger than Earth, its gravity is very similar. Neptune is a gas giant, while Earth is a rocky planet.
Can we breathe on Neptune?
Humans need oxygen to breathe, and there is almost no oxygen in Neptune’s atmosphere. Neptune’s atmosphere is mostly hydrogen, with some helium and a small amount of methane. This means that Humans would not be able to breathe on Neptune.
Are there storms on Neptune?
As a gas giant, Neptune has powerful winds, and it is one of the stormiest planets in the Solar System. Using the Hubble Space Telescope, scientists have discovered many dark spots on Neptune’s surface, similar to the Great Red Spot found on Jupiter.
These spots are enormous storms, some of which continue for many years. The wind speed near these storms has been measured as between 700 and 1200 miles per hour (ca. 1,931 km/h).
