Comets of the solar system. Study of Comet Churyumov-Gerasimenko What does the comet's trajectory look like?

20.11.202327.05.2017

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What is a comet?

If we examine the meaning of the word "comet", we come to its ancient Greek equivalent. Literally it means “with long hair.” Thus, the name was given in view of the structure of this Comet, which has a “head” and a long “tail” - a kind of “hair”. The head of a comet consists of a nucleus and perinuclear substances. The loose core may contain water, as well as gases such as methane, ammonia and carbon dioxide. The comet Churyumov-Gerasimenko, discovered on October 23, 1969, has the same structure.

How the comet was previously represented

In ancient times, our ancestors revered her and invented various superstitions. Even now there are those who associate the appearance of comets with something ghostly and mysterious. Such people may think that they are wanderers from another world of souls. Where did this come from? Perhaps the whole point is that the appearance of these heavenly creatures ever coincided with some unkind incident.

However, as time passed, the idea of what small and large comets were changed. For example, a scientist like Aristotle, studying their nature, decided that it was a luminous gas. After a while, another philosopher named Seneca, who lived in Rome, suggested that comets are bodies in the sky moving in their orbits. However, real progress in their study was achieved only after the creation of the telescope. When Newton discovered the law of gravity, things took off.

Current ideas about comets

Today, scientists have already established that comets consist of a solid core (from 1 to 20 km in thickness). What does the comet's nucleus consist of? From a mixture of frozen water and cosmic dust. In 1986, photographs of one of the comets were taken. It became clear that its fiery tail is an emission of a stream of gas and dust, which we can observe from the earth's surface. For what reason does this “fiery” emission occur? If an asteroid flies very close to the Sun, then its surface heats up, which leads to the release of dust and gas. Solar energy exerts pressure on the solid material that makes up the comet. As a result, a fiery tail of dust is formed. This debris and dust is part of the trail that we see in the sky when we observe the movement of comets.

What determines the shape of a comet's tail?

The post on comets below will help you better understand what comets are and how they work. They come in different varieties, with tails of all sorts of shapes. It's all about the natural composition of the particles that make up this or that tail. Very small particles quickly fly away from the Sun, and larger ones, on the contrary, tend to the star. What is the reason? It turns out that the former move away, pushed by solar energy, while the latter are affected by the gravitational force of the Sun. As a result of these physical laws, we get comets whose tails are curved in different ways. Those tails that are largely composed of gases will be directed away from the star, while corpuscular tails (consisting mainly of dust), on the contrary, will tend to the Sun. What can you say about the density of a comet's tail? Cloud tails can typically measure millions of kilometers, in some cases hundreds of millions. This means that, unlike the body of a comet, its tail consists largely of discharged particles, having practically no density. When an asteroid approaches the Sun, the comet's tail can bifurcate and acquire a complex structure.

The speed of particle movement in a comet's tail

Measuring the speed of movement in a comet's tail is not so easy, since we cannot see individual particles. However, there are cases when the speed of movement of matter in the tail can be determined. Sometimes gas clouds can condense there. From their movement, the approximate speed can be calculated. So, the forces moving the comet are so great that the speed can be 100 times greater than the gravity of the Sun.

How much does a comet weigh?

The entire mass of comets largely depends on the weight of the comet's head, or more precisely, its nucleus. Presumably, the small comet could weigh only a few tons. Whereas, according to forecasts, large asteroids can reach a weight of 1,000,000,000,000 tons.

What are meteors

Sometimes one of the comets passes through the Earth's orbit, leaving a trail of debris in its wake. When our planet passes by the place where the comet was, these debris and cosmic dust remaining from it enter the atmosphere at great speed. This speed reaches more than 70 kilometers per second. When the comet's fragments burn up in the atmosphere, we see a beautiful trail. This phenomenon is called meteors (or meteorites).

Age of comets

Fresh asteroids of enormous size can survive in space for trillions of years. However, comets, like any other one, cannot exist forever. The more often they approach the Sun, the more they lose the solid and gaseous substances that make up their composition. “Young” comets can lose a lot of weight until a kind of protective crust forms on their surface, which prevents further evaporation and burning out. However, the “young” comet ages, and the nucleus becomes decrepit and loses its weight and size. Thus, the surface crust acquires many wrinkles, cracks and breaks. Gas streams, burning, push the body of the comet forward and forward, giving speed to this traveler.

Halley's Comet

Another comet, the structure is the same as the comet Churyumov - Gerasimenko, is an asteroid, discovered. He realized that comets have long elliptical orbits along which they move at large intervals of time. He compared comets that were observed from the earth in 1531, 1607 and 1682. It turned out that it was the same comet, which moved along its trajectory after a period of time equal to approximately 75 years. In the end, she was named after the scientist himself.

Comets in the Solar System

We are in the solar system. At least 1000 comets have been found near us. They are divided into two families, and they, in turn, are divided into classes. To classify comets, scientists take into account their characteristics: the time it takes them to travel the entire path in their orbit, as well as the period from orbit. If we take Halley's Comet mentioned earlier as an example, it completes a full revolution around the sun in less than 200 years. It belongs to periodic comets. However, there are those that cover the entire path in much shorter periods of time - the so-called short-period comets. We can be sure that in our solar system there are a huge number of periodic comets, the orbits of which pass around our star. Such celestial bodies can move so far from the center of our system that they leave Uranus, Neptune and Pluto behind. Sometimes they can come very close to planets, causing their orbits to change. An example is

Comet Information: Long Period

The trajectory of long-period comets is very different from short-period comets. They go around the Sun from all sides. For example, Heyakutake and Hale-Bopp. The latter looked very spectacular when they approached our planet for the last time. Scientists have calculated that the next time they can be seen from Earth will be thousands of years later. A lot of comets with a long period of movement can be found at the edge of our solar system. Back in the mid-20th century, a Dutch astronomer suggested the existence of a cluster of comets. Over time, the existence of a cometary cloud was proven, which is known today as the “Oort Cloud” and was named after the scientist who discovered it. How many comets are there in the Oort Cloud? According to some assumptions, at least a trillion. The period of movement of some of these comets can be several light years. In this case, the comet will cover its entire path in 10,000,000 years!

Fragments of Comet Shoemaker-Levy 9

Reports of comets from all over the world help in their research. Astronomers could observe a very interesting and impressive vision in 1994. More than 20 fragments remaining from Comet Shoemaker-Levy 9 collided with Jupiter at crazy speed (approximately 200,000 kilometers per hour). Asteroids flew into the planet's atmosphere with flashes and huge explosions. The hot gas caused the formation of very large fire spheres. The temperature to which the chemical elements were heated was several times higher than the temperature recorded on the surface of the Sun. After which a very high column of gas could be seen through telescopes. Its height reached enormous dimensions - 3200 kilometers.

Comet Biela - a double comet

As we have already learned, there is plenty of evidence that comets break up over time. Because of this, they lose their brightness and beauty. There is only one example of such a case that can be considered - Biela's comet. It was first discovered in 1772. However, it was subsequently noticed more than once again in 1815, then in 1826 and in 1832. When it was observed in 1845, it turned out that the comet looked much larger than before. Six months later it turned out that it was not one, but two comets that were walking next to each other. What happened? Astronomers have determined that a year ago the Biela asteroid split in two. This is the last time scientists have recorded the appearance of this miracle comet. One part of it was much brighter than the other. She was never seen again. However, over time, a meteor shower, the orbit of which exactly coincided with the orbit of Comet Biela, caught the eye more than once. This incident proved that comets are capable of disintegrating over time.

What happens during a collision

For our planet, a meeting with these celestial bodies does not bode well. A large piece of comet or meteorite, approximately 100 meters in size, exploded high in the atmosphere in June 1908. As a result of this disaster, many reindeer died and two thousand kilometers of taiga were destroyed. What would happen if such a rock exploded over a large city such as New York or Moscow? This would cost the lives of millions of people. What would happen if a comet with a diameter of several kilometers hit the Earth? As mentioned above, in mid-July 1994 it was “bombarded” with debris from comet Shoemaker-Levy 9. Millions of scientists watched what was happening. How would such a collision end for our planet?

Comets and the Earth - ideas of scientists

Information about comets known to scientists sows fear in their hearts. Astronomers and analysts paint terrible pictures in their minds with horror - a collision with a comet. When an asteroid enters the atmosphere, it will cause destruction within the cosmic body. It will explode with a deafening sound, and on Earth you can see a column of meteorite debris - dust and stones. The sky will be covered in a fiery red glow. There will be no vegetation left on Earth, since all forests, fields and meadows will be destroyed due to the explosion and fragments. Due to the fact that the atmosphere will become impenetrable to sunlight, it will become sharply cold, and plants will not be able to carry out photosynthesis. This will disrupt the feeding cycles of marine life. Being without food for a long time, many of them will die. All of the above events will also affect natural cycles. Widespread acid rain will have a detrimental effect on the ozone layer, making it impossible to breathe on our planet. What will happen if a comet falls into one of the oceans? Then this can lead to disastrous environmental disasters: the formation of tornadoes and tsunamis. The only difference will be that these cataclysms will be on a much larger scale than those that we could experience in several thousand years of human history. Huge waves of hundreds or thousands of meters will sweep away everything in their path. There will be nothing left of towns and cities.

"No need to worry"

Other scientists, on the contrary, say that there is no need to worry about such cataclysms. According to them, if the Earth comes close to a celestial asteroid, this will only lead to illumination of the sky and meteor shower. Should we worry about the future of our planet? Is it likely that we will ever be met by a flying comet?

Comet fall. Should you be afraid?

Can you trust everything that scientists present? Do not forget that all the information about comets recorded above is just theoretical assumptions that cannot be verified. Of course, such fantasies can sow panic in the hearts of people, but the likelihood that something similar will ever happen on Earth is negligible. Scientists who study our solar system are amazed at how well thought out everything is in its design. It is difficult for meteorites and comets to reach our planet because it is protected by a giant shield. The planet Jupiter, due to its size, has enormous gravity. Therefore, it often protects our Earth from passing asteroids and comet remnants. The location of our planet leads many to believe that the entire device was thought out and designed in advance. And if this is so, and you are not a zealous atheist, then you can sleep peacefully, because the Creator will undoubtedly preserve the Earth for the purpose for which he created it.

Names of the most famous

Reports about comets from various scientists from all over the world make up a huge database of information about cosmic bodies. Among the particularly well-known are several. For example, comet Churyumov - Gerasimenko. In addition, in this article we could get acquainted with comet Fumeaker-Levy 9 and comets Encke and Halley. In addition to them, comet Sadulayev is known not only to sky researchers, but also to amateurs. In this article, we tried to provide the most complete and verified information about comets, their structure and contact with other celestial bodies. However, just as it is impossible to embrace all the expanses of space, it will not be possible to describe or list all currently known comets. Brief information about the comets of the Solar System is presented in the illustration below.

Sky exploration

The knowledge of scientists, of course, does not stand still. What we know now was not known to us some 100 or even 10 years ago. We can be sure that man's tireless desire to explore the vastness of space will continue to push him to try to understand the structure of celestial bodies: meteorites, comets, asteroids, planets, stars and other more powerful objects. We have now penetrated into such vastness of space that contemplating its immensity and unknowability is awe-inspiring. Many agree that all this could not have appeared on its own and without a purpose. Such a complex design must have an intention. However, many questions related to the structure of space remain unanswered. It seems that the more we learn, the more reasons we have to explore further. In fact, the more information we acquire, the more we understand that we do not know our Solar System, our Galaxy, and even more so the Universe. However, all this does not stop astronomers, and they continue to struggle with the mysteries of existence. Each comet flying nearby is of particular interest to them.

Computer program “Space Engine”

Fortunately, today not only astronomers can explore the Universe, but also ordinary people whose curiosity prompts them to do so. Not long ago, a program for computers called “Space Engine” was released. It is supported by most modern mid-range computers. It can be downloaded and installed completely free of charge using an Internet search. Thanks to this program, information about comets will also be very interesting for children. It presents a model of the entire Universe, including all comets and celestial bodies that are known to modern scientists today. To find a space object of interest to us, for example, a comet, we can use the oriented search built into the system. For example, you need comet Churyumov - Gerasimenko. In order to find it, you need to enter its serial number 67 R. If you are interested in another object, for example, comet Sadulayev. Then you can try entering its name in Latin or entering its special number. Thanks to this program you can learn more about space comets.

The outer space around us is constantly in motion. Following the movement of galactic objects, such as galaxies and clusters of stars, other space objects, including astroid and comets, also move along a clearly defined trajectory. Some of them have been observed by people for thousands of years. Along with the permanent objects in our sky, the Moon and planets, our sky is often visited by comets. Since their appearance, humanity has been able to observe comets more than once, attributing a wide variety of interpretations and explanations to these celestial bodies. For a long time, scientists could not give clear explanations when observing the astrophysical phenomena that accompany the flight of such a swift and bright celestial body.

Characteristics of comets and their differences from each other

Despite the fact that comets are a fairly common phenomenon in space, not everyone is lucky enough to see a flying comet. The thing is that, by cosmic standards, the flight of this cosmic body is a frequent occurrence. If we compare the period of revolution of such a body, focusing on earthly time, this is a rather long period of time.

Comets are small celestial bodies moving in outer space towards the main star of the solar system, our Sun. Descriptions of flights of such objects observed from Earth suggest that they are all part of the solar system, once participating in its formation. In other words, each comet is the remains of cosmic material used in the formation of planets. Almost all known comets today are part of our star system. Like planets, these objects are subject to the same laws of physics. However, their movement in space has its own differences and features.

The main difference between comets and other space objects is the shape of their orbits. If the planets move in the right direction, in circular orbits and lie in the same plane, then the comet rushes through space in a completely different way. This bright star, suddenly appearing in the sky, can move in the right or in the opposite direction, along an eccentric (elongated) orbit. This movement affects the speed of the comet, which is the highest among all known planets and space objects of our Solar System, second only to our main star.

The speed of Comet Halley when passing near the Earth is 70 km/s.

The plane of the comet's orbit does not coincide with the ecliptic plane of our system. Each celestial guest has its own orbit and, accordingly, its own period of revolution. It is this fact that underlies the classification of comets according to their orbital period. There are two types of comets:

short-period with a circulation period from two to five years to a couple of hundred years;
long-period comets that orbit with a period of two or three hundred years to a million years.

The first include celestial bodies that move fairly quickly in their orbit. It is customary among astronomers to designate such comets with the prefixes P/. On average, the orbital period of short-period comets is less than 200 years. This is the most common type of comet found in our near-Earth space and flying within the field of view of our telescopes. The most famous Comet, Halley, completes its run around the Sun in 76 years. Other comets visit our solar system much less frequently, and we rarely witness their appearance. Their orbital period is hundreds, thousands and millions of years. Long-period comets are designated in astronomy by the prefix C/.

It is believed that short-period comets became hostages to the gravitational force of the large planets of the solar system, which managed to snatch these celestial guests from the tight embrace of deep space in the Kuiper belt region. Long-period comets are larger celestial bodies that come to us from the far reaches of the Oort cloud. It is this region of space that is home to all comets, which regularly visit their star. Over millions of years, with each subsequent visit to the solar system, the size of long-period comets decreases. As a result, such a comet can become a short-period comet, shortening its cosmic life.

During observations of space, all comets known to this day have been recorded. The trajectories of these celestial bodies, the time of their next appearance within the solar system were calculated, and the approximate sizes were established. One of them even showed us his death.

The fall of the short-period comet Shoemaker-Levy 9 onto Jupiter in July 1994 was the most striking event in the history of astronomical observations of near-Earth space. A comet near Jupiter broke into fragments. The largest of them measured more than two kilometers. The fall of the celestial guest on Jupiter lasted for a week, from July 17 to July 22, 1994.

It is theoretically possible for the Earth to collide with a comet, but of the number of celestial bodies that we know today, not one of them intersects with the flight path of our planet during its journey. There remains the threat of a long-period comet appearing on the path of our Earth, which is still beyond the reach of detection means. In such a situation, a collision between the Earth and a comet could result in a catastrophe on a global scale.

In total, more than 400 short-period comets are known that regularly visit us. A large number of long-period comets come to us from distant, outer space, being born in 20-100 thousand AU. from our star. In the 20th century alone, more than 200 such celestial bodies were recorded. It was almost impossible to observe such distant space objects through a telescope. Thanks to the Hubble telescope, images of corners of space appeared, in which it was possible to detect the flight of a long-period comet. This distant object looks like a nebula with a tail millions of kilometers long.

Composition of the comet, its structure and main features

The main part of this celestial body is the comet's nucleus. It is in the nucleus that the bulk of the comet is concentrated, which varies from several hundred thousand tons to a million. In terms of their composition, the celestial beauties are icy comets, and therefore, upon close examination, they appear as dirty ice lumps of large sizes. In terms of its composition, an icy comet is a conglomerate of solid fragments of various sizes, held together by cosmic ice. As a rule, the ice of a comet's nucleus is water ice mixed with ammonia and carbon dioxide. Solid fragments consist of meteoric material and can be comparable in size to dust particles or, conversely, measure several kilometers in size.

In the scientific world, it is generally accepted that comets are cosmic deliverers of water and organic compounds in outer space. By studying the spectrum of the celestial traveler's core and the gas composition of its tail, the icy nature of these comic objects became clear.

The processes that accompany the flight of a comet in outer space are interesting. For most of their journey, being at a great distance from the star of our solar system, these celestial wanderers are not visible. Highly elongated elliptical orbits contribute to this. As the comet approaches the Sun, it heats up, which triggers the process of sublimation of space ice, which forms the basis of the comet's nucleus. In plain language, the icy base of the cometary nucleus, bypassing the melting stage, begins to actively evaporate. Instead of dust and ice, the solar wind breaks down water molecules and forms a coma around the comet's nucleus. This is a kind of crown of the celestial traveler, a zone consisting of hydrogen molecules. A coma can be enormous in size, stretching over hundreds of thousands or millions of kilometers.

As the space object approaches the Sun, the speed of the comet rapidly increases, and not only centrifugal forces and gravity begin to act. Under the influence of the Sun's attraction and non-gravitational processes, evaporating particles of cometary matter form the comet's tail. The closer the object is to the Sun, the more intense, larger and brighter the comet's tail, consisting of tenuous plasma. This part of the comet is the most noticeable and visible from Earth is considered by astronomers to be one of the most striking astrophysical phenomena.

Flying close enough to the Earth, the comet allows us to examine its entire structure in detail. Behind the head of a celestial body there is always a trail of dust, gas and meteoric matter, which most often ends up on our planet in the form of meteors.

The history of comets whose flight was observed from Earth

Various space objects constantly fly near our planet, illuminating the sky with their presence. With their appearance, comets often caused unreasonable fear and horror in people. Ancient oracles and stargazers associated the appearance of a comet with the beginning of dangerous periods in life, with the onset of cataclysms on a planetary scale. Despite the fact that the comet's tail is only a millionth of the mass of the celestial body, it is the brightest part of the space object, producing 0.99% of the light in the visible spectrum.

The first comet that was discovered through a telescope was the Great Comet of 1680, better known as Newton's Comet. Thanks to the appearance of this object, the scientist was able to obtain confirmation of his theories regarding Kepler's laws.

During observations of the celestial sphere, humanity managed to create a list of the most frequent space guests who regularly visit our solar system. High on this list is definitely Halley's Comet, a celebrity that has graced us with its presence for the thirtieth time. This celestial body was observed by Aristotle. The closest comet got its name thanks to the efforts of the astronomer Halley in 1682, who calculated its orbit and next appearance in the sky. Our companion flies within our visibility zone with regularity for 75-76 years. A characteristic feature of our guest is that, despite the bright trail in the night sky, the comet's nucleus has an almost dark surface, resembling an ordinary piece of coal.

In second place in popularity and celebrity is Comet Encke. This celestial body has one of the shortest orbital periods, which is equal to 3.29 Earth years. Thanks to this guest, we can regularly observe the Taurids meteor shower in the night sky.

Other most famous recent comets, which blessed us with their appearance, also have enormous orbital periods. In 2011, Comet Lovejoy was discovered, which managed to fly in close proximity to the Sun and at the same time remain unharmed. This comet is a long-period comet, with an orbital period of 13,500 years. From the moment of its discovery, this celestial guest will remain in the region of the solar system until 2050, after which it will leave the confines of near space for many 9000 years.

The most striking event of the beginning of the new millennium, literally and figuratively, was Comet McNaught, discovered in 2006. This celestial body could be observed even with the naked eye. The next visit to our solar system by this bright beauty is scheduled in 90 thousand years.

The next comet that may visit our sky in the near future will probably be 185P/Petru. It will become noticeable starting January 27, 2019. In the night sky, this luminary will correspond to the brightness of 11th magnitude.

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