Gas giants Neptune and Uranus. Temperature on the planets of the solar system Temperature of the planet Neptune
Neptune is the eighth planet in our solar system. Scientists discovered it very first on the basis of constant observations of the sky and deep mathematical research. Urbain Joseph Le Verrier, after lengthy discussions, shared his observations with the Berlin Observatory, where they were studied by Johann Gottfried Galle. It was there that on September 23, 1846, Neptune was discovered. Seventeen days later, his satellite, Triton, was also found.
The planet Neptune is located at a distance of 4.5 billion km from the Sun. For 165 years, it passes its orbit. It cannot be seen with the naked eye, as it is located at a significant distance from the Earth.
In the atmosphere of Neptune, the strongest winds reign, according to some scientists, they can reach speeds of 2100 km / h. In 1989, during the flyby of the Voyager 2 spacecraft in the southern hemisphere of the planet, the Great Dark Spot, exactly the same as the Great Red Spot on the planet Jupiter, was revealed. In the upper atmosphere, the temperature of Neptune is close to 220 degrees Celsius. The temperature at the center of Neptune ranges from 5400°K to 7000-7100°C, which corresponds to the temperature on the surface of the Sun and the internal temperature of most planets. Neptune has a fragmented and faint ring system that was discovered back in the 1960s but officially confirmed in 1989 by Voyager 2.
History of the discovery of the planet Neptune
On December 28, 1612, Galileo Galilei explored Neptune, and then on January 29, 1613. But in both cases, he mistook Neptune for a fixed star that conjoined Jupiter in the sky. That is why the discovery of Neptune was not appropriated by Galileo.
In December 1612, during the first observation, Neptune is at the point of standing, and on the day of observation, he switched to backward movement. Retrograde movement is traced when our planet overtakes the outer planet on its axis. Since Neptune was close to the station, its movement was too weak, and Galileo could not see it with his small telescope.
Alexis Bouvard in 1821 demonstrated astronomical tables of the orbit of the planet Uranus. Later observations showed strong deviations from the tables he created. Given this circumstance, the scientist suggested that an unknown body perturbs the orbit of Uranus with its gravity. He sent his calculations to the Astronomer Royal, Sir George Airy, who asked Cook for clarification. He had already begun drafting an answer, but for some reason did not send it and did not insist on working on this issue.
In 1845-1846, Urbain Le Verrier, independently of Adams, quickly carried out his calculations, but his compatriots did not share his enthusiasm. After reviewing Le Verrier's first estimate of Neptune's longitude and its similarity to Adams' estimate, Airy was able to convince James Chiles, director of the Cambridge Observatory, to begin the search, which lasted from August to September. Twice Chiles actually observed Neptune, but as a result of the fact that he postponed the processing of the results to a later date, he failed to identify the planet in a timely manner.
At this time, Le Verrier convinced the astronomer Johann Gottfried Galle, who works at the Berlin Observatory, to start looking. An observatory student, Heinrich d'Arré, suggested to Galle that he compare a map of the sky drawn in the region of Le Verrier's predicted location with the view of the sky at the moment in order to observe the movement of the planet relative to the fixed stars. On the first night, the planet was discovered after approximately 1 hour of searching. Johann Encke, together with the director of the observatory, continued to observe that part of the sky where the planet was located for 2 nights, as a result of which they discovered its movement relative to the stars and were able to make sure that this was actually a new planet. On September 23, 1846, Neptune was discovered. It is within 1° of Le Verrier's coordinates and approximately 12° of the coordinates predicted by Adams.
Immediately after the discovery, a dispute followed between the French and the British for the right to consider the discovery of the planet as their own. As a result, they reached a consensus and decided to consider Le Verrier and Adams as co-discoverers. In 1998, the “Neptune papers” were once again found, which were illegally appropriated by astronomer Olin J. Eggen and kept with him for thirty years. After his death, they were found in his possession. Some historians, after reviewing the documents, believe that Adams does not deserve equal rights with Le Verrier to discover the planet. In principle, this has been questioned before, for example, since 1966 by Dennis Rawlins. In Dio magazine, he published an article demanding that Adams' equal rights to discovery be recognized as theft. “Yes, Adams did some calculations, but he was somewhat unsure where Neptune was,” Nicholas Kollestrum said in 2003.
Origin of the name Neptune
For a certain time after the discovery, the planet Neptune was designated as the "planet of Le Verrier" or as "the outer planet from Uranus." Halle was the first to propose the idea of an official name, suggesting the name "Janus". Chiles in England suggested the name "Ocean".
Le Verrier, claiming that he had the right to give a name, proposed to call it Neptune, mistakenly believing that this name was recognized by the French bureau of longitudes. The scientist tried to name the planet in October after his own name "Leverrier" and was supported by the director of the observatory, but this initiative ran into resistance outside of France. Almanacs quickly returned the name Herschel (after William Herschel, the discoverer) for Uranus and Le Verrier for the new planet.
But, despite this, Vasily Struve, director of the Pulkovo Observatory, will stop at the name "Neptune". He announced his decision at the congress of the Imperial Academy of Sciences on December 29, 1846, which took place in St. Petersburg. This name received support beyond the borders of Russia and very soon became the accepted international name for the planet.
physical characteristics
Neptune has a mass of 1.0243 × 1026 kg and acts as an intermediate link between the large gas giants and the Earth. Its weight is seventeen times that of the Earth and 1/19 of the mass of Jupiter. As for the equatorial radius of Neptune, it corresponds to 24,764 km, which is almost four times the earth's. Uranus and Neptune are often classified as gas giants ("ice giants") due to their high concentrations of volatiles and their smaller size.
Internal structure
It is immediately worth noting that the internal structure of the planet Neptune is similar to the structure of Uranus. The atmosphere is approximately 10-20% of the total mass of the planet, the distance from the surface to the atmosphere is 10-20% of the distance from the surface of the planet to the core. The pressure near the core can be 10 GPa. Concentrations of ammonia, methane and water are found in the lower atmosphere.
This hotter and darker area gradually condenses into a superheated liquid mantle, the temperature of which reaches 2000 - 5000 K. The weight of the planet's mantle exceeds the Earth's by ten to fifteen times, according to various estimates, it is rich in ammonia, water, methane and other compounds. This matter, according to generally accepted terminology, is called icy, even though it is a dense and very hot liquid. This liquid, which has a high electrical conductivity, is often called the ocean of aqueous ammonia. Methane at a depth of 7 thousand km decomposes into diamond crystals, "falling" on the core. Scientists have hypothesized that there is a whole ocean of "diamond liquid". The core of the planet is composed of nickel, iron and silicates and weighs 1.2 times more than our planet. In the center, the pressure reaches 7 megabars, which is millions of times greater than that of the Earth. In the center, the temperature reaches 5400 K.
Atmosphere of Neptune
Scientists have discovered helium and a waterfall in the upper atmosphere. At this height, they are 19% and 80%. In addition, traces of methane are traced. Methane absorption bands are traced at wavelengths exceeding 600 nm in the infrared and red parts of the spectrum. As with Uranus, methane's absorption of red light is a key factor in giving Neptune's blue hue, although the bright azure differs from Uranus's mild aquamarine. Since the percentage of methane in the atmosphere is not much different from that of Uranus, scientists hypothesize that there is some unknown component of the atmosphere that contributes to the blue color. The atmosphere is divided into two main regions, namely the lower troposphere, in which there is a decrease in temperature with height, and the stratosphere, where another pattern is observed - the temperature increases with height. The tropopause boundary (located between them) is located at a pressure level of 0.1 bar. At a pressure level below 10-4 - 10-5 microbars, the stratosphere is replaced by the thermosphere. Gradually, the thermosphere passes into the exosphere. Models of the troposphere allow us to assume that, taking into account the height, it consists of clouds of approximate compositions. In the pressure zone below 1 bar there are clouds of the upper level, where the temperature is conducive to methane condensation.
Clouds of hydrogen sulfide and ammonia form at pressures between 1 and 5 bar. At higher pressure clouds can be composed of ammonium sulfide, ammonia, water, and hydrogen sulfide. Deeper, at a pressure of about 50 bar, clouds of water ice can form, in the case of a temperature of 0 °C. Scientists suggest that this zone may contain clouds of hydrogen sulfide and ammonia. In addition, it is possible that clouds of hydrogen sulfide and ammonia can be found in this zone.
For such a low temperature, Neptune is too far from the Sun for it to warm up the thermosphere with UV radiation. It is possible that this phenomenon is a consequence of atmospheric interaction with ions located in the planet's magnetic field. Another theory says that the main heating mechanism is gravity waves from the inner regions of Neptune, which subsequently dissipate in the atmosphere. The thermosphere includes traces of carbon monoxide and water that got there from external sources (dust and meteorites).
Climate of Neptune
It is from the differences between Uranus and Neptune - the level of meteorological activity. Voyager 2, which flew near uranium in 1986, recorded weak atmospheric activity. Neptune, in contrast to Uranus, showed clear weather changes when the survey was taken in 1989.
The weather on the planet is distinguished by a serious dynamic system of storms. Moreover, the wind speed can sometimes reach about 600 m/s (supersonic speed). In the course of tracking the movement of clouds, a change in wind speed was noticed. Eastward from 20 m/s; on the western - to 325 m / s. As for the upper cloud layer, here the wind speed also varies: along the equator from 400 m/s; at the poles - up to 250 m/s. At the same time, most winds give a direction that is opposite to the rotation of Neptune around its axis. The diagram of the winds shows that their direction at high latitudes coincides with the direction of rotation of the planet, and at low latitudes it is completely opposite to it. The difference in the direction of the winds, as scientists believe, is a consequence of the “screen effect” and is not associated with deep atmospheric processes. The content of ethane, methane and acetylene in the atmosphere in the equatorial region is tens or even hundreds of times higher than the content of these substances in the region of the poles. Such an observation gives reason to believe that upwelling exists at Neptune's equator and closer to the poles. In 2007, scientists noticed that the upper troposphere at the planet's south pole was 10°C warmer than the rest of Neptune, which averages -200°C. Moreover, such a difference is quite enough for methane in other areas of the upper atmosphere to be in a frozen form, gradually leaking into space at the south pole.
Due to seasonal changes, the cloud bands in the planet's southern hemisphere have increased in albedo and size. This trend was traced back in 1980, according to experts, it will last until 2020 with the onset of a new season on the planet, which changes every forty years.
Moons of Neptune
Currently, Neptune has thirteen known moons. The largest of them weighs more than 99.5% of the total mass of all satellites on the planet. This is Triton, which was discovered by William Lassell seventeen days after the discovery of the planet itself. Triton, unlike other large satellites in our solar system, has a retrograde orbit. It is possible that it was captured by Neptune's gravity, and may have been a dwarf planet in the past. It is at a small distance from Neptune to be fixed in synchronous rotation. Triton, due to tidal acceleration, slowly spirals towards the planet and as a result, when the Roche limit is reached, it will be destroyed. As a result, a ring is formed that will be more powerful than the rings of Saturn. It is assumed that this will happen after a period of 10 to 100 million years.
Triton is one of 3 satellites that have an atmosphere (along with Titan and Io). The possibility of the existence of a liquid ocean under the ice crust of Triton, similar to the ocean of Europa, is pointed out.
The next discovered satellite of Neptune was Nereid. It has an irregular shape and is one of the highest orbital eccentricities.
Between July and September 1989, six more new satellites were discovered. Among them, it is worth noting Proteus, which has an irregular shape and high density.
The four inner moons are Thalassa, Naiad, Galatea and Despina. Their orbits are so close to the planet that they are within its rings. Larissa, following them, was first discovered in 1981.
Between 2002 and 2003, five more irregular moons of Neptune were discovered. Since Neptune was considered the Roman god of the seas, his moons were named after other sea creatures.
Watching Neptune
It's no secret that Neptune is not visible from Earth to the naked eye. The dwarf planet Ceres, the Galilean moons of Jupiter, and the asteroids 2 Pallas, 4 Vesta, 3 Juno, 7 Iris, and 6 Hebe appear brighter in the sky. To observe the planet, you need a telescope with a magnification of 200x and a diameter of at least 200-250 mm. In this case, you can see the planet as a small bluish disk, reminiscent of Uranus.
Every 367 days, for an earthly observer, the planet Neptune enters into an apparent retrograde motion, forming certain imaginary loops against the background of other stars during each opposition.
Observation of the planet in the radio wave range shows that Neptune is a source of irregular flashes and continuous radiation. Both phenomena are explained by a rotating magnetic field. In the infrared part of the spectrum, Neptune's storms are well traced. You can set their size and shape, as well as accurately track their movement.
NASA plans to launch the Neptune Orbiter to Neptune in 2016. To date, no exact launch dates have been officially announced; this device is not included in the plan for exploring the solar system.
The eighth from the planet is the gas giant - Neptune. The planet is named after the Roman god of the seas and oceans. Neptune is the fourth planet in diameter and third in mass. It has a mass 17 times that of .
Neptune was first discovered by Galileo in 1612 and 1613, and immortalized in his drawings. Since Neptune was in close proximity to during the observation, Galileo considered it to be a star.
In 1812, Alexis Bouvard, a French astronomer known for discovering eight comets and creating astronomical tables, calculated the orbit of Uranus. He stated that there is some celestial body that affects the orbit. In 1843, John Adams calculated the orbit of a proposed eighth planet using parameters from an anomaly in the orbit of Uranus.
Urbain Le Verrier, a French mathematician and astronomer, was actively engaged in the search for the eighth planet. The search for a new eighth planet was carried out by the German observatory and Johann Halle, who used a reflector. He came up with the idea of comparing a real sky map with the image seen through a telescope and focusing on objects moving against the background of fixed stars.
Neptune has a mass 17 times that of the Earth. The radius of the planet is 24,764 km, which is four times the radius of the Earth.
Neptune is similar in composition to Uranus.
The atmosphere makes up 5 to 10% of the total mass of the planet, and has a pressure of 10 GPa. In the lower part of the atmosphere, a concentrated solution of ammonia, hydrogen and water was found. The gas gradually goes into a supercritical state (a state in which the pressure and temperature are much higher than the pressure and temperature of the substance's critical point), forming a liquid or ice crust at temperatures between 2,000 and 5,000 degrees Kelvin. This crust contains large amounts of water, ammonia and methane and has a high electrical conductivity. It is believed that diamond crystals are formed at a depth of about 7000 km of methane decomposition.
The composition of the core may include iron, nickel and silicon under a pressure of 7 mbar.
The atmosphere of the planet consists of 80% hydrogen and 19% helium. A small amount of methane was also found. The bluish color of the planet gives the absorption of the red spectrum by methane.
The atmosphere itself is divided into two zones: the troposphere (where the temperature decreases with height) and the stratosphere (where it happens the other way around). These two zones are separated by the tropopause.
There may be clouds in the atmosphere, the chemical composition of which changes with height, the clouds are composed of ammonia and hydrogen sulfide, hydrogen sulfide and water.
Neptune has a dipole magnetic field.
The planet is surrounded by rings, but different from those of Saturn. They are composed of ice particles, silicates and hydrocarbons.
Three main rings can be distinguished: the Adams ring (located 63,000 km from Neptune), the Le Verrier ring (53,000 km), and the Halle ring (42,000 km).
The weather on Neptune is variable, winds blowing on the surface, at a speed of 600 m / s. These winds blow in the opposite direction of the planet's rotation. In 1989, Voyager 2 discovered the Great Dark Spot, an enormous anticyclone (13,000 km x 6,600 km). After a few years the stain disappeared.
Neptune is surrounded by 13 moons. The largest of them, Triton (in Greek mythology was the son of Poseidon), discovered in 1846 by William Lassell.
In all of history, only the Voyager 2 spacecraft has been near Neptune. The signal went from it to the Earth for 246 minutes.
Information about the planet Neptune
| open | John Cooch Adams |
| opening date |
September 23, 1846 |
| Average distance from the Sun |
4,498,396,441 km |
| Minimum distance from the Sun (perihelion) |
4,459,753,056 km |
| Maximum distance from the Sun (apohelion) |
4,537,039,826 km |
| Period of revolution around the sun |
164.79132 Earth years, 60,190.03 Earth days |
| Orbit circumference |
28,263,736,967 km |
| Average orbital speed |
19566 km/h |
| Average planet radius |
24,622 km |
| Equator length |
154,704.6 km |
| Volume |
62,525,703,987,421 km3 |
| Weight |
102 410 000 000 000 000 000 000 000 kg |
| Density |
1.638 g/cm3 |
| total area |
7,618,272,763 km2 |
| Surface gravity (free fall acceleration) |
11.15 m/s 2 |
| Second space velocity |
84 816 km/h |
| Sidereal rotation period (day length) |
0.671 Earth days, 16.11000 hours |
| average temperature |
-214°C |
| Composition of the atmosphere |
Hydrogen, helium, methane |
When astronomer Johann Gottfried Galle did find the planet in 1846, both mathematicians chalked it up to the discovery. And then they fought for a long time, finding out who was the first to make the discovery, and they still haven’t decided (for them). Astronomers decided to equally share the merits of the discoverers between Le Verrier and Adams.
- The strongest winds in the solar system are on Neptune
Think a hurricane is scary? Imagine a hurricane with winds that accelerate to 2100 km/h. As you can probably imagine, scientists are wondering how clouds can move so fast on a cold, icy planet like Neptune. It is believed that cold temperatures and the flow of liquid gases in the planet's atmosphere can reduce friction so that the winds gain significant speed.
- Neptune is the coldest planet in the solar system
In the upper layers of the clouds, the temperature on Neptune can drop to -221.45 degrees Celsius. This is more than half the freezing point of water, and an unprotected person will turn to ice in no time. On Pluto, of course, it is even colder (temperatures drop to -240 degrees Celsius). But Pluto isn't a planet anymore, remember?
- Neptune has rings
When people think of ring systems, Saturn often comes to mind helpfully. It may surprise you, but Neptune also has a ring system. True, it should not be compared with the bright and wide rings of Saturn. Neptune has five rings, and each is named after the astronomers who made important discoveries about Neptune: Galle, Le Verrier, Lassell, Arago, and Adams.
These rings are at least 20% dust (in some, its content reaches 70%) micron sizes, similar to the particles that make up the rings of Jupiter. The remaining materials of the ring are represented by small stones. The planet's rings are difficult to see because they are dark (probably due to the presence of organic components that have changed under the influence of cosmic radiation. They are similar to the rings of Uranus, but very different from the ice rings around Saturn.
It is believed that the rings of Neptune are relatively young - much younger than the solar system and much younger than the rings of Uranus. Under the theory that Triton was a Kuiper belt object captured by Neptune's gravity, it is believed that they (the rings) were the result of a collision of the planet's original moons.
- Neptune likely caught its elder moon Triton
Neptune's largest moon Triton moves around Neptune in a retrograde orbit. This means that its orbit around the planet lies backwards compared to other moons of Neptune. This is considered a sign that Neptune apparently captured Triton - that is, the moon did not form in place, like the rest of Neptune's moons. Triton is locked in synchronous rotation with Neptune and is slowly spiraling towards the planet.
At some point, billions of years from now, Triton will likely be torn apart by Neptune's gravitational forces and become a beautiful ring around the planet. This ring will be attracted and fall to the planet. It is a pity that this will not happen soon, because the spectacle will certainly be beautiful.
- Neptune has only been seen up close once.
The only spacecraft that has ever visited Neptune was NASA's Voyager 2, which visited the planet during its . Voyager 2 flew past Neptune on August 25, 1989, passing less than 3,000 kilometers from the planet's north pole. It was the closest approach to an object that Voyager 2 had made since launching from Earth.
During its flyby Voyager 2 studied the atmosphere of Neptune, its rings, magnetosphere and got acquainted with Triton. Voyager 2 also took a look at Neptune's Great Dark Spot, a rotating storm system that has disappeared, according to Hubble Space Telescope observations. It was originally thought to be a large cloud, but information gathered by Voyager has shed light on the true nature of this phenomenon.
- There are no plans to visit Neptune again
The beautiful photographs of Neptune taken by Voyager 2 will be the only ones we have for a long time, since no one plans to fly to the Neptune system again. However, NASA considered a possible Flagship mission, which was supposed to take place in the late 2020s and early 2030s.
Another NASA proposal was Argo, a spacecraft that was planned to be launched in 2019 to visit Jupiter, Saturn, Neptune and the Kuiper belt object. The focus of the Argo was to be Neptune and its moon Triton, which the device was supposed to explore sometime in 2029. But so far it hasn't.
Summing up and recalling all of the above, it can be noted with surprise that Neptune may well be one of the most interesting planets (in terms of the number of awards), not counting, of course, the Earth. Perhaps future missions that will be sent to the outer edges of the solar system will show even more interesting things.
It will be no secret to anyone that the Earth is the only habitable planet in our solar system. All planets, except the Earth, are distinguished by the absence of a breathable atmosphere, and many of them are also too hot or vice versa - frozen worlds.
The planets of our solar system with respect to scale, in the lower left part of the picture - the orbits of the planets / NASA image
The “habitable zone” exists in every star system that has a planet; it is a certain conditional area, while being in which the existence of water in the liquid phase is possible on the planets. In this connection, on such planets or their satellites, conditions arise that are suitable for the appearance of life similar to the earth.
So, hot and cold worlds in our solar system! What exactly do we know about the temperatures of their surfaces and what actually affects these temperatures?
Photo of Mercury obtained from the American automatic interplanetary station Messenger / photo NASA Of the eight planets in the Solar System, Mercury is the closest to the Sun, so we would expect it to be the "hottest" on our list. However, since it has no atmosphere and rotates around its axis very slowly, the temperature on its surface fluctuates over fairly wide ranges.
Slow rotation around the axis leads to the fact that the side of Mercury facing the Sun heats up to 427 ° C. Meanwhile, on the opposite side, temperatures drop to -173°C, so Mercury's average temperature will be 67°C.
Venus is an incredibly hot and hostile world, due to a combination of its dense atmosphere and proximity to the Sun / NASA image / JPL Venus, the second closest planet to the Sun, also boasts high surface temperatures of up to 470°C. Such a temperature on the surface of Venus is due to the greenhouse effect, slow rotation around the axis, as well as proximity to the Sun. Due to the dense atmosphere, daily temperature fluctuations are insignificant, despite being on the very border of the habitable zone, life on Venus in our understanding is impossible.
Greenhouse gases and the density of Venus's atmosphere have created the strongest greenhouse effect, much of the sun's heat is retained by the planet's atmosphere, and the surface is a barren and molten landscape. On the surface of Venus there are thousands of ancient volcanoes that erupted lava in the past, hundreds of craters, the planet's crust is very thin, it is weakened by high temperatures and does little to prevent lava eruptions outward. An extremely inhospitable place by any measure!
Earth is the third planet from the Sun and is still the only inhabited planet known to us. The average temperature of the Earth's surface is 7.2 °C and it varies depending on a number of factors. A significant influence on the temperatures of the northern and southern hemispheres of the planet has an axial tilt, which means that at certain times of the year one of the hemispheres receives more light from the Sun, while the other hemisphere, on the contrary, less.
But despite all this, there are also extreme places on Earth, for example, in Antarctica, a record low temperature of -91.2 ° C was recorded, and in Death Valley, located in the Mojave Desert region, USA, a positive temperature of 56.7 °C
The thin atmosphere of Mars, visible on the horizon, is too weak to keep the planet warm / NASA image The average temperature on the surface of Mars is -55 ° C, but temperature fluctuations also occur on the Red Planet. At the equator, temperatures reach 20 °C, while at the poles the thermometer drops to -153 °C. But on average, Mars is much colder than Earth, due to its thin atmosphere that can't hold heat from the Sun, and because it's on the outer edge of the habitable zone.
Jupiter is a gas giant and the largest planet in the solar system / photo NASA / JPL / University Jupiter is a gas giant and the largest planet in the solar system. It doesn't have a surface and so we can't measure its temperature, but measurements taken in Jupiter's upper atmosphere showed a temperature of around -145°C, as we get closer to the planet's center we see an increase in temperature due to atmospheric pressure.
At a point where Jupiter's atmospheric pressure is ten times greater than on Earth, the temperature reaches 21 ° C, which we consider comfortable, and at the core of the planet the temperature reaches up to 35,700 ° C - hotter than at the surface of the Sun.
Saturn and its rings, photo transmitted by the Cassini spacecraft / NASA / JPL / Space Science Institute / Gordan Ugarkovic Saturn is the second largest planet after Jupiter, a cold gas giant, with an average temperature of -178 ° C. Due to the tilt of Saturn's axis, the southern and northern hemispheres heat up differently, resulting in seasonal temperature fluctuations and powerful winds on the planet. Like Jupiter, the temperature in the upper atmosphere of Saturn is quite low, but closer to the center of the planet, the temperature rises. It is assumed that in the core of the planet the temperature reaches 11,700 °C.
Image of Uranus obtained from the spacecraft Voyager 2 in 1986 / photo NASA / JPL / Voyager Uranus - unlike the gas giants of Jupiter and Saturn, which consist mainly of hydrogen and helium, there is no metallic hydrogen in the bowels of Uranus, as well as Neptune similar to it, but ice is present in large quantities, in high-temperature modifications, which is why these two the planets were singled out in a separate class - "Ice giants". The temperature of Uranus at a pressure of 0.1 bar is -224 °C, which makes it the coldest planet in the solar system, Uranus even colder than Neptune, which is farther from the Sun.
Image of Neptune obtained from the Voyager 2 spacecraft / photo NASA / JPL / Voyager The temperature of Neptune's upper atmosphere drops to -218 ° C, the planet is the second coldest place in our solar system. But like all gas giants, Neptune has a hot core, the temperature of which is about 7000 ° C. The weather on the planet is destructive, storms and winds reach supersonic speeds, most of the winds on Neptune blow in the direction opposite to the rotation of the planet, the general wind pattern shows, that at high latitudes the direction of the winds coincides with the rotation of the planet, and at low latitudes it is opposite to it.
In summary, our solar system is going from extreme to extreme, from extreme cold to unbearably hot, and in general there are only a few places that are sufficiently habitable to support life. And of all places, Earth is the only planet most suitable for sustaining permanent life.
Although, of course, the word "giant" will be a little strongly said in relation to Neptune, the planets, although very large by cosmic standards, are nevertheless significantly inferior in size to other giant planets of ours:, Saturn and. Speaking of Uranus, this planet, although larger than Neptune, is still 18% larger than Uranus in terms of mass. In general, this planet, named because of its blue color in honor of the ancient god of the seas, Neptune can be considered the smallest of the giant planets and at the same time the most massive - the density of Neptune is many times stronger than that of other planets. But compared to that Neptune, that our Earth is tiny, if you imagine that our Sun is the size of a door, then the Earth is the size of a coin, and Neptune is the same size as a big baseball.
History of the discovery of the planet Neptune
The history of the discovery of Neptune is unique in its kind, since it is the first planet in our solar system that was discovered purely theoretically, thanks to mathematical calculations, and only then it was seen through a telescope. It was like this: back in 1846, the French astronomer Alexis Bouvard observed the movement of the planet Uranus through a telescope and noticed strange deviations in its orbit. The anomaly in the motion of the planet, in his opinion, could be caused by the strong gravitational influence of some other large celestial body. Alexis' German colleague, astronomer Johann Galle, made the necessary mathematical calculations to determine the location of this previously unknown planet, and they turned out to be correct - our Neptune was soon discovered at the supposed location of the unknown "planet X".
Although long before that, the great planet Neptune was observed in a telescope. True, in his astronomical notes he noted it as a star, not a planet, so the discovery was not credited to him.
Neptune is the most distant planet in the solar system
“But how?”, you probably ask. In fact, everything is not as simple as it seems at first glance. Since its discovery in 1846, Neptune has rightfully been considered the most distant planet from the Sun. But in 1930, a small Pluto was discovered, which is even further away. But here there is one caveat, the orbit of Pluto is strongly elongated along an ellipse in such a way that at certain moments of its movement, Pluto is closer to the Sun than Neptune. The last time such an astronomical phenomenon occurred from 1978 to 1999 - for 20 years Neptune again had the title of full-fledged "the most distant planet from the Sun."
Some astronomers, in order to get rid of these confusions, even proposed to “demote” Pluto from the title of a planet, they say, it’s just a small celestial body flying in orbit, or to assign the status of a “dwarf planet”, however, disputes on this subject are still ongoing.
Features of the planet Neptune
Neptune has its bright blue appearance due to the strong density of clouds in the planet's atmosphere, these clouds conceal chemical compounds that are still completely unknown to our science, which, when absorbed by sunlight, turn blue. One year on Neptune is equal to our 165 years, it is during this time that Neptune completes its full cycle in orbit around the Sun. But the day on Neptune is not as long as a year, they are even shorter than our earthly ones, since they last only 16 hours.
Temperature of Neptune
Since the sun's rays reach the distant "blue giant" in a very small amount, it is natural that it is very, very cold on its surface - the average surface temperature there is -221 degrees Celsius, which is two times lower than the freezing point of water. In a word, if you were on Neptune, then in the blink of an eye you would turn into an ice.
Surface of Neptune
The surface of Neptune consists of ammonia and methane ice, but the core of the planet may well turn out to be stone, but this is still just a hypothesis. It is curious that the force of gravity on Neptune is very similar to the earth, it is only 17% more than ours, and despite the fact that Neptune is 17 times larger than the Earth. Despite this, we are unlikely to be able to walk around Neptune in the near future, see the previous paragraph about the ice. And besides, the strongest winds blow on the surface of Neptune, the speed of which can reach up to 2400 kilometers per hour (!), perhaps, on no other planet in our solar system there are such strong winds as here.
Size of Neptune
As mentioned above, it is 17 times larger than our Earth. The picture below shows a comparison of the sizes of our planets.
Atmosphere of Neptune
The composition of the atmosphere of Neptune is similar to the atmospheres of most similar giant planets: atoms and helium mainly prevail there, and ammonia, frozen water, methane and other chemical elements are also present in small quantities. But unlike other large planets, Neptune's atmosphere contains a lot of ice, due to its remote position.
Rings of the planet Neptune
Surely when you hear about the rings of the planets, Saturn immediately comes to mind, but in fact he is far from the only owner of the rings. Rings, albeit not as large and beautiful as those, our Neptune also has. Altogether, Neptune has five rings named after the astronomers who discovered them: Gallé, Le Verrier, Lassell, Arago, and Adams.
The rings of Neptune are composed of small pebbles and cosmic dust (many micron-sized particles), they are somewhat similar in structure to the rings of Jupiter and are quite difficult to notice, as they are black in color. Scientists believe that the rings of Neptune are relatively young, at least they are much younger than the rings of its neighbor Uranus.
Moons of Neptune
Neptune, like any decent giant planet, has its own satellites and not one, but thirteen, named after the smaller sea gods of the ancient pantheon.
Particularly interesting is the Triton satellite, discovered, among other things, thanks to ... beer. The fact is that the English astronomer William Lasing, who actually discovered Triton, made a big fortune by brewing and selling beer, which subsequently allowed him to invest a lot of money and time in his favorite hobby - astronomy (especially to equip a high-quality observatory is not cheap).
But what is interesting and unique about Triton? The fact is that this is the only known satellite in our solar system that revolves around the planet in the opposite direction relative to the rotation of the planet itself. In scientific terminology, this is called "rotation in a retrograde orbit." Scientists suggest that Triton was not a satellite at all before, but an independent dwarf planet (like Pluto), which by fate fell into the sphere of influence of Neptune's gravity, in fact captured by the "blue giant". But the matter did not end there: Neptune's gravity pulls Triton closer and closer, and after a few million light years, gravitational forces can tear the satellite apart.
How long is the flight to Neptune
For a long time. This is, in short, with modern technology, of course. After all, the distance from Neptune to the Sun is 4.5 billion kilometers, and the distance from Earth to Neptune is 4.3 billion kilometers, respectively. The only satellite sent from Earth to Neptune, Voyager 2, launched in 1977, flew to its destination only in 1989, where it photographed the "great dark spot" on the surface of Neptune and observed a series of powerful storms in the planet's atmosphere.
Planet Neptune video
And at the end of our article, we offer you an interesting video about the planet Neptune.
