Interesting facts about the sun, comets and asteroids. What is the difference between a comet and an asteroid? Heavenly peace and earthly peace
Since ancient times, people have sought to uncover the secrets that the sky holds. Since the first telescope was created, scientists have been gradually collecting grains of knowledge that are hidden in the boundless expanses of space. It's time to find out where the messengers from space - comets and meteorites - came from.
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.
The largest known meteorite occurred about 65 million years ago. It had a diameter of several kilometers and tore apart a crater with a diameter of 180 kilometers. The impact sent so much dust into the air that the sun darkened for hundreds of years. All over the world, plants and animals became extinct - this was the end of the dinosaurs.
Luckily, such large meteorites are very rare, so we don't need to worry. Also, unlike dinosaurs, we can observe the sky with telescopes and detect such large asteroids long before impact. While the shooting star burns after a few seconds, another phenomenon remains visible for a long time: tailed comets linger for days or weeks in the sky. For them, people usually attributed many attributes as divine signs, preachers of misfortune or harbingers of joyful events.
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.
But the truth is somewhat less impressive. Astronomers also call comets "dirty snowballs." They come from the outer solar system, far from solar energy. It's so cold there that the water instantly freezes to ice. This creates pieces of ice chunks and dust-proof snowballs.
What are asteroids made of?
The comet also moves far away from the Sun - until it veers away from the collision and heads towards the inner solar system. He gets closer to the sun and eventually gets more light and warmth. This causes the frozen surface to thaw and even evaporate. This creates a blanket of water vapor and dust around the comet.
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.
At the same time, the comet receives "solar wind" - tiny particles that fly towards the sun at high speed. They fell into the comet's steam envelope. As a result, the comet's vapor envelope is blown away, forming an elongated sun cloud. When this cloud is struck by sunlight, it appears as a streak of light - the tail of a comet.
The comet flies around the sun and then leaves again. When it is away from the sun, thawing and evaporation stop. The tail disappears and the comet paints like a dirty snowball across the vastness of the outer solar system. Depending on the comet's train, it takes many decades or even centuries until it returns to the sun.
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 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.
A disaster of unimaginable proportions: almost 15 million years ago, a gigantic explosion hit southern Germany. This was over a hundred thousand atomic bombs together, killing every creature within a radius of at least a hundred kilometers. At that time, people did not exist, but all animals and plants were killed or buried by a huge pressure wave. You even heard an explosion on the other side of the earth.
The impact of this fault caused the eighth earthquake and tore a 24-kilometer crater on the surface of the earth. The scenery around the impact crater was completely destroyed: 150 cubic kilometers of rock were thrown into the air and flew partly 450 kilometers to what is now the Czech Republic. Fortunately, impacts from such heavy meteorites are very rare, occurring only once every few million years.
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 density? comet 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.
This crater also dates back to a meteorite impact, but this crater was only 150 meters high. Two meteorite rattles so close to each other - could it be a coincidence? No, say scientists who examined the crater rocks: both craters were created at the same time. Either a small part of the meteorite was broken on its way to the ground and separated, or the asteroid long ago had a small companion that fell to the ground with it.
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.
What is our solar system and how did it come to be?
The Earth is not alone in space: for a long time, people have observed the sun, moon and stars in the sky. First they discovered that some stars were moving. These wandering stars were observed and their paths followed. But for a long time their movements were not understood - until five hundred years ago, a man named Nicholas Copernicus solved the riddle: the earth and the "wandering stars" are indeed planets, all of which orbit the sun at different distances.
Today we know eight planets. 
It is the planet closest to the Sun. These four inner planets have a rocky, rocky surface and are still relatively close to the sun—just a few hundred million kilometers. They are made of gas and are much larger than the inner planets.
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).
Jupiter and Saturn are about ten times larger than Earth, which is why they are called giants. Finally, there are asteroids, comets and dust clouds that also surround the sun. The gravity of the sun holds all these celestial bodies together and makes them fly in a circle like a long line. Everything is called the solar system. Moons are also part of this, but are held back by the planet's attractiveness.
But why does the sun have planets? It all depends on how the sun appeared: a cloud of gas and dust, collected by its own gravity, became a star. But not all of the material in this cloud was “locked up” in the star—about one percent remained. And when the sun began to glow, the radiation pushed the rest of the matter out again.
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.
Light gases were pushed far out, while heavier particles of dust and rock remained close to the sun. Planets were formed from these dust and gas clouds over time. This is why the solar system has gas planets, planetary rockets - including our earth - and a sun in the middle. It contains 99% of the mass of the solar system and holds everything together with its gravity.
Since its inception, the earth has changed significantly: mountains, seas and continents have appeared and disappeared, animal and plant species have spread and become extinct. Most of these changes happened very slowly, over many millions of years. But from time to time, dramatic events occurred: over the course of several thousand years, environmental conditions changed dramatically.
Halley's Comet
Another comet, the structure is the same as the comet Churyumov - Gerasimenko, is an asteroid discovered by Edmund Halley. He realized that comets have long elliptical orbits in which they move at large intervals. 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.
For scientists who study Earth's history, these radical changes are like a new chapter in a book: they divide Earth's history into different sections called eons. In the beginning, 4.5 billion years ago, the earth was completely uninhabited. It emerged as a hot ball of glowing molten rock surrounded by hot, corrosive and poisonous gases. This sounds like a description of hell - and from the Greek word "Hades" comes also the name of this time: Hadaicum. This ended about four billion years ago with the first major change: the earth was so cooled that the surface became hard - the earth gained a crust.
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 is great amount periodic comets whose orbits 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 Encke.
The earth cooled further so that liquid water could collect on the crust: seas appeared. And in these seas, life began about 3.8 billion years ago, but initially only in the form of simple bacteria. The Greek word for origin or beginning in the name of this time is: archaic. An important climate change about 2.5 billion years ago marked the transition to the next era: primitive creatures began to influence the environment. They produced oxygen, which until now has almost disappeared from the atmosphere.
Comet Information: Long Period
Trajectory of movement long-period comets very different from short-period ones. 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 on 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? 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!
Early single-celled life forms became more complex over time, forming cell nuclei. Later, some began to cooperate in strong alliances - eventually the first multicellular organisms appeared. However, they still did not have hard shells or skeletons, so almost no fossils remain from this time. This period before the formation of fossils should have its own name: the Proterozoic.
The Proterozoic ended with an explosion of life 550 million years ago: in a short time, a wide variety of species arose from primitive life forms. These species were much more complex, and some also had hard shells, which were first preserved as fossils. Therefore, for scientists, the history of life becomes so real from this moment. And according to the Greek term “visible” this era is also: Phanerozoic.
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.
This age of life lasts 550 million years to this day. However, the development of life was uneven: after the explosive spread of life, two devastating mass deaths occurred. 
The oldest era of the Phanerozoic began 550 million years ago with the massive formation of new species. They are called the ancient or Paleozoic era. The first life occurred only in the oceans. Then plants colonized the earth, and later also moved animal world: First, amphibians evolved, which were already a little on land, and finally also reptiles, which became independent of water and conquered the earth.
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.
The earth erupted about 251 million years ago with the largest mass death of all time. More than 90 percent of all animal and plant species have become extinct, especially in the seas. The reason is still not clear. Scientists suspect an Ice Age, possibly the result of a meteorite, is to blame.
When the surviving animal and plant species had to become accustomed to their new environment, the Mesozoic or Mesozoic era broke out. This is especially the age of the dinosaurs: the huge lizards evolved and dominated life for almost 200 million years. But the center of the Earth also ended with an abrupt event: about 65 million years ago, big meteorite. Once the dust and ash were released into the air, the sky darkened and the climate changed for a long time. Dinosaurs and many other species died.
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 people died reindeer and two thousand kilometers of taiga were destroyed. What would happen if such a block burst over big 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 flies into the atmosphere, it will cause irreversible destruction processes inside 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 nutritional cycles. sea creatures. 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 happens if the comet will fall to 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 celestial asteroid, then 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 form 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 known this moment 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 comet that interests us, for example, 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.
On warm summer nights it is pleasant to walk under the starry sky, look at the wonderful constellations on it, and make wishes at the sight of a falling star. Or was it a comet passing by? Or maybe a meteorite? There are probably more astronomy experts among romantics and lovers than among planetarium visitors.
Mysterious space
Questions that constantly arise during contemplation require answers, and celestial mysteries require solutions and scientific explanations. For example, what is the difference between an asteroid and a meteorite? Not every schoolchild (or even adult) will be able to answer this question right away. But let's start in order.
Asteroids
To understand the difference between an asteroid and a meteorite, you need to define the concept of “asteroid”. This word from ancient Greek is translated as “star-like”, since these celestial bodies, when observed through a telescope, resemble stars rather than planets. Until 2006, asteroids were often called minor planets. Indeed, the movement of asteroids in general is no different from planetary movement, because it also occurs around the Sun. Asteroids differ from ordinary planets in their small size. For example, the most large asteroid Ceres is only 770 km across.
Where are these star-like space inhabitants? Most asteroids move along long-studied orbits in the space between Jupiter and Mars. But some small planets still cross the orbit of Mars (such as the asteroid Icarus) and other planets, and sometimes even come closer to the Sun than Mercury.
Meteorites
Unlike asteroids, meteorites are not inhabitants of space, but its messengers. Each earthling can see a meteorite with his own eyes and touch it with his own hands. A large number of them are kept in museums and private collections, but it must be said that meteorites look rather inconspicuous. Most of them are gray or brownish-black pieces of stone and iron.
So, we managed to figure out how an asteroid differs from a meteorite. But what can unite them? Meteorites are believed to be fragments of small asteroids. Stones flying in space collide with each other, and their fragments sometimes reach the surface of the Earth.
The most famous meteorite in Russia is the Tunguska meteorite, which fell in the remote taiga on June 30, 1908. In the recent past, namely in February 2013, attracted everyone's attention Chelyabinsk meteorite, whose numerous fragments were found in the area of Lake Chebarkul in the Chelyabinsk region.
Thanks to meteorites, unique guests from space, scientists, and with them all the inhabitants of the Earth, have an excellent opportunity to learn about the composition of celestial bodies and get an idea of the origin of the universe.
Meteora
The words “meteor” and “meteorite” come from the same Greek root, meaning “heavenly”. We know what a meteorite is, and how it differs from a meteor is not difficult to understand.
A meteor is not a specific celestial object, but an atmospheric phenomenon that looks like It occurs when fragments of comets and asteroids burn up in the Earth's atmosphere.
A meteor is a shooting star. It may appear to observers, fly back into outer space, or burn up in the Earth's atmosphere.
It is also not difficult to understand how meteors differ from asteroids and meteorites. The last two celestial objects are concretely tangible (even if theoretically in the case of an asteroid), and the meteor is a glow resulting from the combustion of cosmic fragments.
Comets
An equally wonderful celestial body that an earthly observer can admire is a comet. How do comets differ from asteroids and meteorites?
The word “comet” is also of ancient Greek origin and is literally translated as “hairy”, “shaggy”. Comets come from the outer solar system, and therefore have a different composition than asteroids that formed near the Sun.
Besides the difference in composition, there is a more obvious difference in the structure of these celestial bodies. When approaching the Sun, a comet, unlike an asteroid, exhibits a hazy coma shell and a tail consisting of gas and dust. As the comet heats up, its volatile substances are actively released and evaporated, turning it into a beautiful luminous celestial object.
In addition, asteroids move in orbits, and their movement in outer space resembles the smooth and measured movement of ordinary planets. Unlike asteroids, a comet is more extreme in its movements. Its orbit is highly elongated. The comet either approaches the Sun closely or moves away from it to a considerable distance.
A comet differs from a meteorite in that it is in motion. A meteorite is the result of a collision celestial body with the earth's surface.
Heavenly peace and earthly peace
It must be said that watching the night sky is doubly pleasant when its unearthly inhabitants are well known and understandable to you. What a pleasure it is to tell your interlocutor about the world of stars and unusual events in outer space!
And the point is not even in the question of how an asteroid differs from a meteorite, but in the awareness of the close connection and deep interaction between the earthly and cosmic worlds, which must be established as actively as the relationship between one person and another.