In the hectic 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 on the scale of the universe. Maybe that's why young romantics dream of devoting themselves to space exploration and the study of stars. 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 in the degree of remoteness from the Sun, inaccessible for direct observation and therefore doubly attractive to researchers.
How it all began
Back in the middle of the XIX century, the solar system, according to scientists, contained only seven planets. Neighbors of the Earth, near and far, were studied using all the available achievements in the field of technology and computing. Many characteristics were initially described theoretically, and only then found practical confirmation. The situation with the calculation of the orbit of Uranus was somewhat different. Thomas John Hussey, an astronomer and priest, discovered a mismatch between the real trajectory of the planet's intended movement. There could be only one conclusion: there is an object that affects the orbit of Uranus. In fact, this was the first report on the planet Neptune.
After almost ten years (in 1843), two researchers simultaneously calculated in which orbit the planet could move, forcing the gas giant to squeeze. These were the Englishman John Adams and the Frenchman Urbane Jean Joseph Le Verrier. Independently of each other, but with different accuracy, they determined the path of movement of the body.
Detection and designation
Neptune was found in the night sky by the astronomer Johann Gottfried Halle, to whom Le Verrier arrived with his calculations. The French scientist, who later shared with Halle and Adams the fame of the discoverer, was mistaken in calculations only by a degree. Neptune officially appeared in scientific works on September 23, 1846.
Initially, the planet was proposed to be named after the two-faced Janus, but this designation did not take root. Astronomers were more inspired by comparing the new object with the king of the seas and oceans, as alien to the earth’s firmament as, apparently, the open planet. The name Neptune was proposed by Le Verrier and supported by V. Ya. Struve, who headed the Pulkovo Observatory. The name was given, it only remained to understand what the composition of the atmosphere of Neptune was, whether it was at all what was hidden in its bowels 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 the Earth in size: its diameter is almost 4 times larger, and its mass is 17 times. The considerable distance from the Sun leaves no doubt that the weather on the planet Neptune is also significantly different from the Earth. There is no and cannot be life. It's not even about the wind or some unusual phenomena. The atmosphere and surface of Neptune are almost the same structure. This is a characteristic feature of all gas giants, which include this planet.
Imaginary surface
The planet is significantly inferior in density to the Earth (1.64 g / cm³), so it’s not easy to step on its surface. Yes, and as such it is not. It was agreed to identify the surface level by pressure: a pliable and rather liquid-like “solid” is located in the lower layers of the atmosphere, where pressure equals one bar, and, in fact, is a part of it. Any message about the planet Neptune as a space object of a specific size is based on such a definition of the imaginary surface of a giant.
The parameters obtained taking into account this feature are as follows:
The ratio of these characteristics makes Neptune in form far from the circle. He, like the Blue Planet, is somewhat flattened from the poles.
The composition of the atmosphere of Neptune
The mixture of gases enveloping the planet is very different in content from the earth. The vast majority is hydrogen (80%), helium is in the second position. This inert gas makes a significant contribution to the atmosphere of Neptune - 19%. Methane is less than a percent, ammonia is also found here, but in a small amount.
Oddly enough, one percent of the methane in the composition strongly affects what kind of atmosphere Neptune has and what is the entire gas giant from the point of view of an external observer. This chemical compound makes up the clouds of the planet and does not reflect light waves corresponding to red. As a result, for spacecraft flying past , Neptune is colored in saturated blue. 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. Neptune stands out among them precisely for color. Due to such characteristics, it is called the ice planet. Frozen methane, by its existence adding weight to the comparison of Neptune with an iceberg, is also part of the mantle surrounding the core of the planet.
Internal structure
The core of the space object contains iron, nickel, compounds of magnesium and silicon. The mass of the core is approximately equal to the entire Earth. Moreover, unlike other elements of the internal structure, it has a density that is twice as high as the similar parameter of the Blue Planet.
The core is covered, as already mentioned, with the mantle. Its composition is largely similar to atmospheric: there are ammonia, methane, water. The mass of the layer is equal to fifteen earthly, while it is very hot (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 top of the structure. The smooth transformation of one element into another and the blurry boundaries between them are properties characteristic of all gas giants.
Research difficulties
Conclusions about the atmosphere of Neptune, which is characteristic of its structure, are made largely on the basis of data already obtained about Uranus, Jupiter and Saturn. The remoteness of the planet from the Earth greatly complicates its study.
In 1989, the Voyager 2 spacecraft flew near Neptune. It was the only meeting of the ice giant with the earthly messenger. Its fruitfulness, however, is obvious: it was this ship that provided most of the information about Neptune to science. In particular, Voyager 2 has discovered Big and Small dark spots. Both blackened areas were clearly visible against a 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 atmosphere and sweep around the planet at great speed.
Perpetual motion
Many parameters are determined by the presence of the atmosphere. Neptune is characterized not only by an unusual color, but also by the constant movement created by the wind. The speed with which clouds fly around the planet at the equator is more than a thousand kilometers per hour. At the same time, they move in the opposite direction with respect to the rotation of Neptune itself around the axis. At the same time, the planet turns around even faster: a complete turn 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 a peak on Neptune. This phenomenon has not yet been substantiated, as well as some temperature features of the planet.
Heat distribution
Weather on the planet Neptune is characterized by a gradual change in temperature depending on altitude. That layer of the atmosphere where the conditional surface is located is fully consistent with the second name of the cosmic body (ice planet). The temperature here drops to almost -200 ºC. If you move above the surface, then there will be a noticeable increase in heat up to 475º. Scientists still have not found a worthy explanation for such differences. Neptune is thought to have an internal heat source. Such a “heater” should produce twice as much energy as it comes to the planet from the Sun. The heat from this source, combined with the energy reaching here from our star, is probably the cause of strong winds.
However, neither sunlight, nor an internal “heater” can increase the temperature on the surface so that the change of seasons is noticeable here. And although other conditions for this are respected, it is impossible to distinguish winter from summer on Neptune.
Magnetosphere
Voyager 2 research has helped scientists learn a lot about Neptune's magnetic field. It is very different from the earth: the source is located not in the core, but in the mantle, due to which the magnetic axis of the planet is strongly shifted relative to its center.
One of the functions of the field is protection from the solar wind. The shape of the Neptune magnetosphere is very 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 inconsistency of the field voltage and the location of the magnetic lines. Such properties of the planet are also not yet fully explained by science.
Rings
At the end of the XIX century, when scientists were no longer looking for the answer to the question of whether there is an atmosphere on Neptune, they faced a different task. It was necessary to explain why, along the route of the eighth planet, the stars began to fade for the observer somewhat earlier than Neptune approached them.
It turned out to solve the problem 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, later named after one of the pioneers of Neptune - John Adams.
Further research found several more similar formations. It was they who covered the stars along the path of the planet. Today, astronomers consider Neptune to be the owner of six rings. There is another mystery 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 think that the force of the gravitational field of one of Neptune's satellites - Galatea, holds them in this position. Others cite a powerful counterargument: its dimensions are so small that it is unlikely that it would be able to cope with the task. Perhaps there are several more unknown satellites nearby helping Galatea.
In general, the planet’s rings are a spectacle inferior to the similar formations of Saturn in impressiveness and beauty. Not the last role in a somewhat lackluster appearance is played by the composition. The rings mainly contain blocks of methane ice, coated with silicon compounds, which absorb light well.
Satellites
Neptune is the owner (according to the latest data) of 13 satellites. Most of them are small in size. Outstanding parameters only in Triton, only slightly inferior in diameter to the moon. The composition of the atmosphere of Neptune and Triton is different: the satellite has a gas shell of a mixture of nitrogen and methane. These substances give a very interesting look to the planet: frozen nitrogen with inclusions of methane ice creates a riot of colors on the surface near the South Pole: yellow overflows combine with white and pink.
The fate of the handsome Triton, meanwhile, is not so rosy. Scientists predict him a collision with Neptune and its absorption. As a result, the eighth planet will become the owner of a new ring, in brightness comparable to the formations of Saturn and even ahead of them. The remaining moons of Neptune are significantly inferior to Triton, some of them do not even have a name yet.
The eighth planet of the solar system is largely consistent with its name, the choice of which was affected by the presence of the atmosphere - Neptune. Its composition contributes to the appearance of a characteristic blue color. Neptune rushes through an incomprehensible space, like the god of the seas. And similarly to the ocean depths, that part of the cosmos that begins beyond Neptune keeps a ton of secrets from man. Future scientists have yet to discover them.