In the bustle of days, the world for an ordinary person sometimes shrinks to the size of work and home. Meanwhile, if you look at the sky, you can see how insignificant it is. Perhaps that is why young romantics dream of devoting themselves to the conquest of space and the study of the stars. Scientists-astronomers do not forget for a second that, in addition to the Earth with its problems and joys, there are many other distant and mysterious objects. One of them is the planet Neptune, the eighth most distant from the Sun, inaccessible to direct observation and therefore doubly attractive to researchers.
How it all began
Back in the mid-19th century, the solar system, according to scientists, contained only seven planets. The Earth's neighbors, immediate and distant, have been studied using all available advances in technology and computing. Many characteristics were first described theoretically, and only then found practical confirmation. With the calculation of the orbit of Uranus, the situation was somewhat different. Thomas John Hussey, an astronomer and priest, discovered a discrepancy between the real trajectory of the planet and the expected one. There could be only one conclusion: there is an object influencing the orbit of Uranus. In fact, this was the first message about the planet Neptune.
Almost ten years later (in 1843), two researchers simultaneously calculated the orbit in which a planet could move, forcing the gas giant to make room. These were the Englishman John Adams and the Frenchman Urbain Jean Joseph Le Verrier. Independently of each other, but with varying accuracy, they determined the path of movement of the body.
Detection and designation
Neptune was found in the night sky by astronomer Johann Gottfried Halle, to whom Le Verrier came with his calculations. The French scientist, who later shared the glory of the discoverer with Galle and Adams, was wrong in his calculations by only a degree. Neptune officially appeared in scientific works on September 23, 1846.
Initially, it was proposed to name the planet, but this designation did not take root. Astronomers were more inspired by comparing the new object with the king of the seas and oceans, just as alien to the earth’s surface as, apparently, the discovered planet. The name of Neptune was proposed by Le Verrier and supported by V. Ya. Struve, who headed the name was given, all that remained was to understand what the composition of Neptune’s atmosphere was, whether it existed at all, what was hidden in its depths, and so on.
Compared to Earth
A lot of time has passed since the opening. Today we know much more about the eighth planet of the solar system. Neptune is significantly larger than Earth: its diameter is almost 4 times greater and its mass is 17 times greater. The significant distance from the Sun leaves no doubt that the weather on the planet Neptune is also noticeably different from that on Earth. There is no and cannot be life here. It's not even about the wind or any unusual phenomena. The atmosphere and surface of Neptune are practically the same structure. This is a characteristic feature of all gas giants, of which this planet is one.
Imaginary surface
The planet's density is significantly lower than that of Earth (1.64 g/cm³), making it difficult to step on its surface. Yes, and as such it does not exist. They agreed to identify the surface level by the magnitude of the pressure: the pliable and rather liquid-like “solid” is located in the lower levels where the pressure is equal to one bar, and, in fact, is part of it. Any message about the planet Neptune as a cosmic object of a specific size is based on this definition of the imaginary surface of the giant.
The parameters obtained taking into account this feature are as follows:
the diameter at the equator is 49.5 thousand km;
its size in the plane of the poles is almost 48.7 thousand km.
The ratio of these characteristics makes Neptune far from a circle in shape. It, like the Blue Planet, is somewhat flattened at the poles.
Composition of Neptune's atmosphere
The mixture of gases that envelops the planet is very different in content from that on Earth. The overwhelming majority is hydrogen (80%), the second position is occupied by helium. This inert gas makes a significant contribution to the composition of Neptune's atmosphere - 19%. Methane makes up less than a percent; ammonia is also found here, but in small quantities.
Oddly enough, one percent of methane in the composition greatly affects what kind of atmosphere Neptune has and what the entire gas giant is like from the point of view of an external observer. This chemical compound makes up the planet's clouds and does not reflect light waves corresponding to the color red. As a result, Neptune appears a deep blue to those passing by. This color is one of the mysteries of the planet. Scientists do not yet fully know what exactly leads to the absorption of the red part of the spectrum.
All gas giants have an atmosphere. It is the color that makes Neptune stand out among them. Due to such characteristics, it is called an ice planet. Frozen methane, which by its existence adds weight to the comparison of Neptune with an iceberg, is also part of the mantle surrounding the planet’s core.
Internal structure
The core of the space object contains iron, nickel, magnesium and silicon compounds. The core is approximately equal in mass to the entire Earth. Moreover, unlike other elements of the internal structure, it has a density that is twice that of the Blue Planet.
The core is covered, as already mentioned, by a mantle. Its composition is in many ways similar to the atmospheric one: ammonia, methane, and water are present here. The mass of the layer is equal to fifteen Earth times, while it is very heated (up to 5000 K). The mantle does not have a clear boundary, and the atmosphere of the planet Neptune smoothly flows into it. A mixture of helium and hydrogen makes up the upper part in the structure. The smooth transformation of one element into another and blurred boundaries between them are properties characteristic of all gas giants.
Research challenges
Conclusions about what kind of atmosphere Neptune has, which is characteristic of its structure, are made largely on the basis of data already obtained about Uranus, Jupiter and Saturn. The planet's distance from Earth makes it much more difficult to study.
In 1989, the Voyager 2 spacecraft flew near Neptune. This was the only meeting with an earthly messenger. Its fruitfulness, however, is obvious: most of the information about Neptune was provided to science by this ship. In particular, Voyager 2 discovered the Large and Small Dark Spots. Both blackened areas were clearly visible against the background of the blue atmosphere. Today it is not clear what the nature of these formations is, but it is assumed that these are vortex flows or cyclones. They appear in the upper layers of the atmosphere and sweep around the planet at great speed.
Perpetual motion
Many parameters are determined by the presence of atmosphere. Neptune is characterized not only by its unusual color, but also by the constant movement created by the wind. The speed at which clouds fly around the planet near the equator exceeds a thousand kilometers per hour. At the same time, they move in the opposite direction relative to the rotation of Neptune itself around its axis. At the same time, the planet turns even faster: a complete rotation takes only 16 hours and 7 minutes. For comparison: one revolution around the Sun takes almost 165 years.
Another mystery: the wind speed in the atmosphere of gas giants increases with distance from the Sun and reaches its peak on Neptune. This phenomenon has not yet been substantiated, as well as some temperature features of the planet.
Heat distribution
The weather on the planet Neptune is characterized by a gradual change in temperature depending on altitude. The layer of the atmosphere where the conventional surface is located fully corresponds to the second name (ice planet). The temperature here drops to almost -200 ºC. If you move higher from the surface, you will notice an increase in heat up to 475º. Scientists have not yet found a worthy explanation for such differences. Neptune is supposed to have an internal source of heat. Such a “heater” should generate twice as much energy as what comes to the planet from the Sun. The heat from this source, combined with the energy flowing here from our star, is likely the cause of the strong winds.
However, neither sunlight nor an internal “heater” can raise the temperature on the surface so that the change of seasons is noticeable here. And although other conditions for this are met, it is impossible to distinguish winter from summer on Neptune.
Magnetosphere
Voyager 2's research helped scientists learn a lot about Neptune's magnetic field. It is very different from Earth’s: the source is located not in the core, but in the mantle, due to which the planet’s magnetic axis is greatly shifted relative to its center.
One of the functions of the field is protection from solar wind. The shape of Neptune's magnetosphere is highly elongated: the protective lines in the part of the planet that is illuminated are located at a distance of 600 thousand km from the surface, and on the opposite side - more than 2 million km.
Voyager recorded the variability of field strength and the location of magnetic lines. Such properties of the planet have also not yet been fully explained by science.
Rings
At the end of the 19th century, when scientists were no longer looking for an answer to the question of whether there is an atmosphere on Neptune, another task arose before them. It was necessary to explain why, along the route of the eighth planet, the stars began to fade out for the observer somewhat earlier than Neptune approached them.
The problem was solved only after almost a century. In 1984, with the help of a powerful telescope, it was possible to examine the brightest ring of the planet, which was later named after one of the discoverers of Neptune, John Adams.
Further research discovered several more similar formations. They were the ones who blocked the stars on the planet's path. Today, astronomers consider Neptune to have six rings. There is another mystery hidden in them. The Adams ring consists of several arches located at some distance from each other. The reason for this placement is unclear. Some researchers are inclined to believe that the force of the gravitational field of one of Neptune’s satellites, Galatea, holds them in this position. Others provide a compelling counter-argument: its size is so small that it is unlikely that it would cope with the task. There may be several more unknown satellites nearby that are helping Galatea.
In general, the planet’s rings are a spectacle, inferior in impressiveness and beauty to similar formations of Saturn. The composition plays an important role in the somewhat dull appearance. The rings mostly contain blocks of methane ice coated with silicon compounds that absorb light well.
Satellites
Neptune has (according to the latest data) 13 satellites. Most of them are small in size. Only Triton has outstanding parameters, only slightly inferior in diameter to the Moon. The composition of the atmosphere of Neptune and Triton is different: the satellite has a gaseous envelope of a mixture of nitrogen and methane. These substances give a very interesting appearance to the planet: frozen nitrogen with inclusions of methane ice creates a real riot of colors on the surface in the area of the South Pole: tints of yellow combined with white and pink.
The fate of the handsome Triton, meanwhile, is not so rosy. Scientists predict that it will collide with Neptune and be absorbed by it. As a result, the eighth planet will become the owner of a new ring, comparable in brightness to the formations of Saturn and even ahead of them. The remaining satellites of Neptune are significantly inferior to Triton, some of them do not even have names yet.
The eighth planet of the solar system largely corresponds to its name, the choice of which was influenced by the presence of an atmosphere - Neptune. Its composition contributes to the appearance of the characteristic blue color. Neptune rushes through space incomprehensible to us, like the god of the seas. And similar to the ocean depths, that part of space that begins beyond Neptune keeps a lot of secrets from humans. Scientists of the future have yet to discover them.
Neptune is the eighth planet in the solar system, making it the most distant from the sun. It is possible that this gaseous, giant planet formed much closer to the Sun in the history of the Solar System before drifting away to its current position. Like Saturn, this planet has rings, but they are very faint and do not look as impressive.
Characteristics of the planet
- Equatorial diameter: 49,528 km
- Polar diameter: 48,682 km
- Mass: 1.02 × 10 26 kg (17 earth elements)
- Moons: 14 (Triton)
- Rings: 5
- Distance to orbit: 4,498,396,441 km (30.10 AU)
- Circulation period: 60,190 days (164.8 years)
- Effective temperature: -214°C
- Opening date: September 23, 1846
- Discovered: Urbain Lesterrier and Johann Halle
physical characteristics |
| Polar compression | 0.0171± 0.0013 |
|---|---|
| Equatorial radius | 24,764± 15 km |
| Polar radius | 24,341 ± 30 km |
| Surface area | 7.6408 10 9 km² |
| Volume | 6.254 10 13 km³ |
| Weight | 1.0243 10 26 kg |
| Average density | 1.638 g/cm³ |
| Acceleration of free fall at the equator | 11.15 m/s² |
| Second escape velocity | 23.5 km/s |
| Equatorial rotation speed | 2.68 km/s 9648 km/h |
| Rotation period | 0.6653 days 15 h 57 min 59 s |
| Axis tilt | 28.32° |
| Right ascension of the north pole | 19h 57m 20s |
| North pole declination | 42.950° |
| Albedo | 0.29 (Bond) 0.41 (geom.) |
| Apparent magnitude | 8.0-7.78 m |
| Angular diameter | 2.2″-2.4″ |
Orbit and rotation |
| Perihelion | 4,452,940,833 km 29.76607 a. e. |
|---|---|
| Aphelion | 4,553,946,490 km 30.44125 a. e. |
| Major axle shaft | 4,503,443,661 km 30.10366 a. e. |
| Eccentricitytorbits | 0,011214 |
| Sidereal period | 60,190.03 days 164.79 years |
| Synodic circulation period | 367.49 days |
| Orbital speed | 5.4349 km/s |
| Average anomaly | 267.7672° |
| Mood | 1.767975° |
| Longitude of the ascending node | 131.7943° |
| Periapsis argument | 265.6468° |
| Whose satellite | Sun |
| Satellites | 14 |
Facts about the planet Neptune
- Neptune was not known to anyone until 1846.
- The planet is not visible to the naked eye and was first discovered in 1846 using mathematical calculations. Named after the Roman god of the sea.
- The planet rotates quickly around its axis.
- Neptune is the smallest of the ice giants.
- Despite the fact that the planet is smaller in size than the gas giant Uranus, it has a large mass. Neptune's atmosphere consists mainly of hydrogen, helium and methane. The planet's inner core is believed to be rocky.
- Methane absorbs red light, which turns the planet blue. Images from space observatories show floating clouds in the atmosphere.
- Neptune has a very hurricane climate.
- Large storms swirl at speeds of 600 meters per second in the upper atmosphere. One of the largest observed storms was recorded in 1989. It was called the Great Dark Spot. This phenomenon continued for about five years.
- Neptune has very thin rings, presumably made of ice and fine dust and possibly carbon.
- It has 14 moons.
- The most interesting moon is Triton, an icy world that spews geysers of nitrogen ice. Most likely, Triton was captured by Neptune's gravitational pull a long time ago. This is probably the coldest world in the solar system.
- Only one space observatory, Voyager 2, was sent to the planet in 1989. He sent back the first close-up images of the planet. Later, Yubble also studied the planet.
Neptune's Mysterious Great Dark Spot
The Great Dark Spot is located in the southern part of the planet, and was discovered in 1989. It was an incredibly large rotating storm with winds of up to 1,500 mph, the strongest winds recorded in the solar system. How such powerful winds were discovered on a planet so far from the sun is still considered a mystery.
Data from the Voyager 2 spacecraft also showed that the Great Dark Spot is changing in size. When Neptune was viewed by the Hubble Space Telescope in 1994, the Great Dark Spot had disappeared, although a smaller dark spot had appeared in the northern hemisphere.
Known satellites of Neptune
Neptune has 13 known satellites, which were named after creatures from ancient Greek mythology. .
Gradation of Neptune's satellites by size |
| < 10 км | 10–30 km | 30–100 km | 101–300 km | 301–1000 km | >1000 km |
Neptune satellites table
| № | Name | Semimajor axis in km | Tilt in degrees | Circulation period in days | Diameter in km | Weight 10 19 kg | opening date |
|---|---|---|---|---|---|---|---|
| I | Triton | 354 800 | 156,834 | 5,877 | 2707 | 21000 | 1846 |
| II | Nereid | 5 513 400 | 7,232 | 360,14 | 340 | 3,1 | 1949 |
| III | Naiad | 48 227 | 4,746 | 0,294 | 67 | 0,019 | 1989 |
| IV | Thalassa | 50 075 | 0,209 | 0,311 | 81 | 0.035·10 | 1989 |
| V | Despina | 52 526 | 0,064 | 0,335 | 150 | 0,21 | 1989 |
| VI | Galatea | 61 953 | 0,062 | 0,429 | 175 | 0,21 | 1989 |
| VII | Larissa | 73 548 | 0,205 | 0,555 | 195 | 0,049 | 1981/ 1989 |
| XIV | Polyphemus | 105 300 | 0 | 0,96 | 18 | ? | 2013 |
| VIII | Proteus | 117 647 | 0,026 | 1,122 | 420 | 5,0 | 1989 |
| IX | Galimeda | 15 728 000 | 134,101 | 1879,71 | 48 | 0,009 | 2002 |
| X | Psamatha | 46 695 000 | 137,39 | 9115,9 | 28 | 0,0015 | 2003 |
| XI | Sao | 22 422 000 | 48,511 | 2914,0 | 44 | 0,0067 | 2002 |
| XII | Laomedea | 23 571 000 | 34,741 | 3167,85 | 42 | 0,0008 | 2002 |
| XIII | Not with | 48 387 000 | 132,585 | 9374 | 60 | 0,017 | 2002 |
Blue atmosphere of the planet Neptune
The eighth planet of the solar system has an incredibly dense atmosphere consisting of 74% hydrogen, 25% helium and approximately 1% methane. Particles of icy methane and other gases in the upper atmosphere give it a dark blue color. Neptune's bright blue-white features also help differentiate it from Uranus.
The atmosphere is divided into the lower troposphere and stratosphere, with the tropopause being the boundary between them. In the lower troposphere, temperatures decrease with altitude, but they increase with altitude in the stratosphere. Hydrocarbons form smog hazes that appear throughout the planet's upper atmosphere, and hydrocarbon snowflakes that form in Neptune's atmosphere are melted before they reach the surface due to high pressure.
Videos dedicated to Neptune
Since it is one of the planets that cannot be seen with the naked eye, Neptune was discovered relatively recently. Considering the distance to it, it was observed very close once - in 1989 by the Voyager 2 spacecraft. However, what we learned about this gas (and ice) giant at that time revealed many secrets and the history of its formation.
Opening and Naming:
The discovery of Neptune took place in the 19th century, although there is evidence that it occurred long before that. For example, Galileo Galilei's drawings of December 28, 1612 and January 27, 1613 contained plotted points that are now known to correspond to the location of Neptune on those dates. However, in both cases, Galileo mistook the planet for .
In 1821, French astronomer Alexis Bouvard published astronomical tables. Subsequent observations showed significant deviations from the tables that Bouvard provided, suggesting that an unknown celestial body was disturbing the orbit of Uranus through gravitational interaction.
The new Berlin Observatory on Linden Street, where the planet Neptune was experimentally discovered. Courtesy: Leibniz-Institute for Astrophysics Potsdam.
In 1843, English astronomer John Couch Adams began his work to study the orbit of Uranus using the data he had obtained and made several different estimates of the planet's orbit for the coming years. In 1845 - 1846, Urban Le Verrier, independently of Adams, carried out his own calculations, which he shared with Johann Gottfried Halle of the Berlin Observatory. Galle confirmed the presence of the planet using coordinates given by Le Verrier on September 23, 1846.
The announcement of the discovery was met with controversy, since Le Verrier and Adams also claimed to be the discoverers. Ultimately, an international consensus was reached in which Le Verrier and Adams were jointly recognized for their contributions to the discovery. However, a re-evaluation by historians of the relevant historical documents in 1998 led to the conclusion that Le Verrier was directly responsible for the discovery and deserved a larger share of the contribution to the discovery.
Claiming his rights to the discovery, Le Verrier proposed naming the planet after himself, but this met with stiff resistance outside France. He also proposed the name Neptune, which was eventually accepted by the international community. This was largely because it was consistent with the nomenclature of other planets, all of which were named after deities from Greco-Roman mythology.
Size, mass and orbit of Neptune:
With an average radius of 24.622 ± 19 km, Neptune is the fourth largest planet in the Solar System and is in . But with a mass of 1.0243 x 10 26 kg, which is 17 times the mass of Earth, it is the third most massive planet, ahead of Uranus. The planet has a very slight orbital eccentricity of 0.0086 and the orbital radius at perihelion is 29.81 astronomical units (4.459 x 10 9 km), and at aphelion 30.33 astronomical units (4.537 x 10 9 km).
Comparison of the sizes of Neptune and Earth. Credit: NASA
The planet Neptune takes 16 hours 6 minutes 36 seconds (0.6713 Earth days) to complete one revolution on its axis (one sidereal rotation), and 164.8 Earth years to complete one orbit around the Sun. This means that a day on Neptune lasts 67% of an Earth day, while a Neptunian year is equivalent to approximately 60,190 Earth days (or 89,666 Neptunian days).
Since Neptune's axial tilt (28.32°) is similar to the Earth's axial tilt (~23°) and (~25°), the planet experiences seasonal climate changes. Combined with its long orbital period, this means that Neptune's seasons last 40 Earth years. Also due to its axial tilt comparable to Earth's, the fact is that the variation in day length throughout the year is no more extreme than on Earth.
Neptune's orbit also has a strong influence on the region behind its orbit known as the Kuiper Belt (also called the "trans-Neptunian belt"). In much the same way it dominates, shaping its structure, as Neptune's gravity dominates the Kuiper Belt. During the existence of the Solar System, some regions of the Kuiper Belt were destabilized by the gravity of the planet Neptune, creating gaps in the structure of the Kuiper Belt.
Also within these empty regions are orbits containing objects with an age equal to . These resonances occur when Neptune's orbital period is an exact fraction of the object's orbital period, meaning that they complete part of the orbit during Neptune's full orbit. The most populous resonance in the Kuiper Belt, with over 200 objects, is the 2:3 resonance.
Objects in this resonance travel 2 orbits for every 3 orbits of Neptune and are called plutinos because the largest known is among them. Although Pluto regularly crosses Neptune's orbit, they can never collide due to the 2:3 resonance.
The planet Neptune has a number of known Trojan objects occupying the L4 and L5 Lagrange points - regions of gravitational stability in front of and behind Neptune in its orbit. Some Neptune Trojans have remarkably stable orbits, and were likely formed with Neptune rather than captured by it.
Composition of the planet Neptune:
Because of its smaller size and higher concentrations of volatiles compared to Jupiter and Saturn, the planet Neptune (much like Uranus) is often called an ice giant, a subclass of the giant planets. Just like Uranus, Neptune's internal structure can be roughly divided into different layers: a rocky core consisting of silicates and metals, a mantle containing water, ammonia and methane in the form of ice, and an atmosphere consisting of hydrogen, helium and methane gases.
Neptune's core is made of iron, nickel and silicates, and scientists believe it contains 1.2 times the mass of Earth. The pressure at the center of the core, according to scientists, is 7 Mbar (700 GPa), twice as high as at the center of the Earth, and temperatures at the center of the planet Pluto reach 5400 Kelvin. At a depth of 7,000 km, conditions may be such that methane is converted into diamond crystals that fall as rocks.
The mantle contains 10-15 Earth masses and is rich in water, ammonia and methane. This mixture is called ice, although it is actually a hot, dense liquid, and is sometimes called an "ammonia water ocean." Meanwhile, the atmosphere contains 5-10% of the planet's mass and extends 10-20% towards the core, where it reaches a pressure of about 10 GPa - 100,000 times the pressure of Earth's atmosphere.
Internal structure of the planet Neptune. Credit: NASA
Elevated concentrations of methane, ammonia and water were found in the lower atmosphere. Unlike Uranus, the planet Neptune has a larger ocean inside, while Uranus has a smaller mantle.
Atmosphere of the planet Neptune:
At high altitudes, Neptune's atmosphere is 80% hydrogen and 19% helium, with traces of methane. Like Uranus, absorption of red light by atmospheric methane is part of what gives Neptune its blue hue, although Neptune is darker and brighter. Since Neptune is similar to Uranus in terms of methane content in the atmosphere, scientists believe that some unknown atmospheric component contributes to a more intense color of Neptune.
Neptune's atmosphere is divided into two main regions: the lower troposphere, where the temperature decreases with altitude, and the stratosphere, where the pressure reaches 0.1 bar (10 kPa). The stratosphere is then replaced by the thermosphere with a pressure of 10 -5 - 10 -4 bar (1-10 Pa), which gradually turns into the exosphere.
Spectral analysis of Neptune suggests that its lower stratosphere is hazy due to the condensation of products of the interaction of ultraviolet radiation and methane (photolysis), which creates ethane and acetylene compounds. The stratosphere also contains trace amounts of carbon monoxide and cyanide, which are responsible for the fact that the stratosphere of the planet Neptune is warmer than the stratosphere of the planet Uranus.
A contrasting image in altered colors, emphasizing the features of Neptune's atmosphere, including wind speed. Credit: Erich Karkoschka.
For reasons that remain unclear, the planet's thermosphere has an unusually high temperature of about 750 Kelvin (476.85 °C). The planet is too far from the Sun for this heat to be generated by its ultraviolet radiation, which means another heating mechanism is involved, which could be the interaction of the atmosphere with ions in the planet's magnetic field or gravitational waves from inside the planet that dissipate into the atmosphere.
Since Neptune is not a solid body, its atmosphere is subject to differential rotation. The broad equatorial zone rotates with a period of about 18 hours, which is slower than the 16.1-hour rotation of the planet's magnetic field. On the contrary, the opposite trend is observed in the polar regions, where the rotation period is 12 hours.
This differential rotation is the most pronounced of any planet in the Solar System and results in strong latitudinal wind shears and destructive storms. Three of the most spectacular storms were spotted in 1989 by the Voyager 2 space probe and then named based on their appearance.
The first of these was a massive anticyclone measuring 13,000 x 6,600 km and resembling Jupiter's Great Red Spot. Called the Great Dark Spot, this storm was no longer detected 5 years later (November 2, 1994), when the Hubble Space Telescope looked at the planet. Instead, a new storm, very similar to the previous one, was discovered in the planet's northern hemisphere, suggesting that these storms have a shorter lifespan than storms on Jupiter.
Reconstruction of Voyager 2 images showing the Great Dark Spot (top left), Scooter (middle), and the Lesser Dark Spot (lower right). Credit: NASA/JPL.
Scooter is another storm, a group of white clouds located further south of the Great Dark Spot. The nickname first appeared during the months Voyager 2 spent near the planet in 1989, when it observed a group of clouds moving at speeds faster than the Great Dark Spot.
The Lesser Dark Spot, a southern cyclone, was the second most intense Neptune storm observed in 1989. Initially it was completely dark, but as Voyager 2 approached the planet, a bright core developed and could be seen in the highest resolution images.
Moons of the planet Neptune:
Neptune has 14 known natural satellites (moons), all but one are named after Greco-Roman sea deities (S/2004 N 1 is not currently named). These satellites are divided into two groups - regular and irregular satellites - based on their orbit and proximity to Neptune. Neptune's regular satellites are Naiad, Thalassa, Despina, Galatea, Larissa, S/2004 N 1 and Proteus. These satellites are the closest to the planet and move in circular orbits in the direction of motion around their Neptune axis and lie in the equatorial plane of the planet.
They extend from 48,227 km (Niad) to 117,646 km (Proteus) from Neptune, and all but the two outermost ones, S/2004 N 1 and Proteus, move in their orbits slower than the orbital period of 0.6713 Earth days. Based on observational data and estimated densities, these satellites range in size and mass from 96 x 60 x 52 km and 1.9 x 10^17 kg (Naiad) to 436 x 416 x 402 km and 50.35 x 10^ 17 kg (Proteus).
This composite image from the Hubble Space Telescope shows the location of the newly discovered moon, designated S/2004 N 1, in orbit around the giant planet Neptune, 4.8 billion kilometers from Earth. Credit: NASA, ESA, and M. Showalter (SETI Institute).
With the exception of Larissa and Proteus, which are the most round, all of Neptune's inner moons are elongated. Their spectrum indicates that they are composed of water ice contaminated with darker material, likely organic compounds. In this regard, Neptune's inner moons are very similar to the moons of Uranus.
Neptune's remaining moons are irregular moons, including Triton. They mainly move in inclined eccentric and often retrograde orbits (against the planet's rotation on its axis) away from Neptune. The only exception is Triton, which orbits closer to the planet and moves in a circular orbit, albeit retrograde and inclined.
In order of distance from the planet, the irregular satellites are Triton, Nereid, Halimeda, Sao, Laomedea, Neso and Psamapha - a group that includes retrograde and prograde (moving in the same direction as the attracting celestial body) objects. With the exception of Triton and Nereid, Neptune's irregular moons are similar to those of other giant planets and are believed to have been gravitationally captured in the past.
In terms of size and mass, the irregular satellites are similar, ranging from approximately 40 km in diameter and a mass of 4 x 10^16 kg (Psamapha) to 62 km and 16 x 10^16 kg (Halimeda). Triton and Nereid are unusual irregular moons and are therefore treated separately from Neptune's five other irregular moons. Four differences are noted between these two and other irregular satellites.
First of all, they are the two largest irregular satellites in the Solar System. Triton is almost an order of magnitude larger than all other known irregular satellites and contains more than 99.5% of the mass of all known satellites orbiting Neptune, including the planet's rings and 13 other known satellites.
Color mosaic image of Triton taken by Voyager 2 in 1989. Credit: NASA/JPL/USGS.
Secondly, they both have atypically small semi-major axes; Triton has an order of magnitude smaller in magnitude than other known irregular satellites. Third, they both have unusual orbital eccentricities: Nereid has one of the most eccentric orbits of any known irregular satellite, while Triton's orbit is almost circular. Finally, Nereid has the lowest orbital inclination of any known irregular satellite.
With an average diameter of about 2,700 km and a mass of 214,080 ± 520 x 10^17 kg, Triton is Neptune's largest moon, and the only one large enough to achieve hydrostatic equilibrium (that is, a spherical shape). Triton is located at a distance of 354,759 km from Neptune between the inner and outer satellites.
Triton moves in a retrograde quasi-circular orbit and is mainly composed of ices of nitrogen, methane, carbon dioxide and water. With a geometric albedo of over 70% and a Bond albedo of 90%, this satellite is one of the brightest objects in the Solar System. Its surface has a reddish tint, due to the interaction of ultraviolet radiation and methane, resulting in the creation of tholins (organic substances in the spectra of the icy bodies of our Solar System).
Characteristics of Neptune:(Items without links are under development)
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- Pluto and N.
- Uranus and N.
Neptune compared to our planet
To really understand how big Neptune is, in fact, it can be compared to another planet, for convenience, we can take our planet for these purposes.
Comparison of the sizes of Earth and Neptune
First, let's look at the sizes of the planets being compared. The diameter of the gas giant is about 49,500 km. This makes it the fourth largest planet in the solar system. Compared to our planet, it is 3.9 times larger.
Its mass is 1.02 x 10*26 kg. It turns out that it is 17 times larger in mass than our home planet.
What about volume? Its volume is 6.3 x 10 * 13 km 3. We could fit 57 planets like ours inside it and still have room left. Our day lasts 24 hours, and the day on the gas giant lasts 16 hours and 6 minutes. A year accordingly lasts 164.79 years.
Many parameters of our planets vary greatly, with the possible exception of one thing: the force of gravity.
The gravity on Neptune (assuming the planet has a hypothetical surface) is only 14% stronger than the gravity on Earth.
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Neptune was discovered based on theoretical calculations. The fact is that Uranus deviates from the calculated orbit, as if it is being attracted by another planet.
British mathematicians and astronomers John Couch Adams(1819-1892) and James Challis in 1845 made a calculation of the approximate location of the planet. At the same time, the French astronomer Urban Le Verrier(1811 - 1877), having made a calculation, convinced him to start searching for a new planet. Neptune was first seen by astronomers on September 23, 1846, not far from the positions that were independently predicted by the Englishman Adams and the Frenchman Le Verrier.
Neptune is significantly distant from the Sun.
General characteristics of the planet Neptune
The mass of the planet is 17 times the mass of the Earth. The radius of the planet is about four Earth radii. Density - The density of the Earth.
Rings have been discovered around Neptune. They are open (broken), that is, they consist of separate arches that are not interconnected. The rings of Uranus and Neptune are similar in appearance.
The structure of Neptune is probably almost the same as that of Uranus.
In contrast, , and Neptune may not have a clear internal stratification. But, most likely, Neptune has a small solid core, equal in mass to the Earth. Neptune's atmosphere is mostly hydrogen and helium with a small amount of methane (1%). Neptune's blue color results from the absorption of red light in the atmosphere by this gas - just like on Uranus.
The planet has a thunderous atmosphere, thin porous clouds consisting of frozen methane. The temperature of Neptune's atmosphere is higher than that of Uranus, therefore about 80% H 2
Rice. 1. Composition of Neptune's atmosphere
Neptune has its own internal heat source - it emits 2.7 times more energy than it receives from the Sun. The average surface temperature of the planet is 235 °C. Neptune experiences strong winds parallel to the planet's equator, large storms and whirlwinds. The planet has the fastest winds in the solar system, reaching 700 km/h. The winds blow on Neptune in a westerly direction, against the planet's rotation.
There are mountain ranges and cracks on the surface. In winter there is nitrogen snow, and in summer fountains break through the cracks.
The Voyager 2 probe discovered powerful cyclones on Neptune, in which wind speeds reach the speed of sound.
The planet's satellites are named Triton, Nereid, Naiad, Thalassa, Proteus, Despina, Galatea, Larissa. In 2002-2005 Five more satellites of Neptune were discovered. Each of the newly discovered ones has a diameter of 30-60 km.
Neptune's largest satellite is Triton. It was opened in 1846 by William Lassell. Triton is larger than the Moon. Almost all the mass of Neptune's satellite system is concentrated in Triton. It has a high density: 2 g/cm 3 .