Comets of the solar system message. Message about comets. Other celestial bodies

People watching a falling star in the sky may wonder, what is a comet? This word translated from Greek means “long-haired”. As it approaches the Sun, the asteroid begins to heat up and takes on an effective appearance: dust and gas begin to fly away from the surface of the comet, forming a beautiful, bright tail.

The appearance of comets

The appearance of comets is almost impossible to predict. Scientists and amateurs have been paying attention to them since ancient times. Large celestial bodies rarely fly past the Earth, and such a sight is fascinating and terrifying. History contains information about such bright bodies that sparkle through the clouds, eclipsing even the Moon with their glow. It was with the appearance of the first such body (in 1577) that the study of the movement of comets began. The first scientists were able to discover dozens of different asteroids: their approach to the orbit of Jupiter begins with the glow of their tail, and the closer the body is to our planet, the brighter it burns.

It is known that comets are bodies that move along certain trajectories. Usually it has an elongated shape, and is characterized by its position relative to the Sun.

The comet's orbit may be the most unusual. From time to time, some of them return to the Sun. Scientists say that such comets are periodic: they fly near planets after a certain period of time.

Comets

Since ancient times, people have called any luminous body a star, and those with tails behind them have been called comets. Later, astronomers discovered that comets are huge solid bodies consisting of large ice fragments mixed with dust and stones. They come from deep space and can either fly past or revolve around the Sun, periodically appearing in our sky. Such comets are known to move in elliptical orbits of varying sizes: some return once every twenty years, while others appear once every hundreds of years.

Periodic comets

Scientists know a lot of information about periodic comets. Their orbits and return times are calculated. The appearance of such bodies is not unexpected. Among them there are short-period and long-period.

Short-period comets include comets that can be seen in the sky several times in a lifetime. Others may not appear in the sky for centuries. One of the most famous short-period comets is Halley's Comet. It appears near the Earth once every 76 years. The length of this giant's tail reaches several million kilometers. It flies so far from us that it seems like a stripe in the sky. Her last visit was recorded in 1986.

Fall of comets

Scientists know of many cases of asteroids falling on planets, and not only on Earth. In 1992, the Shoemaker-Levy giant came very close to Jupiter and was torn into numerous pieces by its gravity. The fragments stretched out into a chain and then moved away from the planet’s orbit. Two years later, the chain of asteroids returned to Jupiter and fell on it.

According to some scientists, if an asteroid flies in the center of the solar system, then it will live for many thousands of years until it evaporates, flying once again near the Sun.

Comet, asteroid, meteorite

Scientists have identified the difference in the meaning of asteroids, comets, and meteorites. Ordinary people use these names to call any bodies seen in the sky and having tails, but this is not correct. From a scientific point of view, asteroids are huge blocks of stone floating in space in certain orbits.

Comets are similar to asteroids, but they have more ice and other elements. When approaching close to the Sun, comets develop a tail.

Meteorites are small rocks and other space debris, less than a kilogram in size. They are usually visible in the atmosphere as shooting stars.

Famous comets

The brightest comet of the twentieth century was Comet Hale-Bopp. It was discovered in 1995, and two years later it became visible in the sky with the naked eye. It could be observed in celestial space for more than a year. This is much longer than the radiance of other bodies.

In 2012, scientists discovered Comet ISON. According to forecasts, it should have become the brightest, but, approaching the Sun, it could not meet the expectations of astronomers. However, it was nicknamed in the media “the comet of the century.”

The most famous is Halley's Comet. She played an important role in the history of astronomy, including helping to deduce the law of gravity. The first scientist to describe celestial bodies was Galileo. His information was processed more than once, changes were made, new facts were added. Once Halley drew attention to a very unusual pattern of the appearance of three celestial bodies with an interval of 76 years and moving almost on the same trajectory. He concluded that these were not three different bodies, but one. Newton later used his calculations to construct a theory of gravity, which was called the theory of universal gravitation. Halley's Comet was last seen in the sky in 1986, and its next appearance will be in 2061.

In 2006, Robert McNaught discovered the celestial body of the same name. According to assumptions, it should not have glowed brightly, but as it approached the Sun, the comet began to quickly gain brightness. A year later, it began to glow brighter than Venus. Flying near the Earth, the celestial body created a real spectacle for earthlings: its tail curved in the sky.

The largest collection of amazing information about celestial bodies. Interesting facts about comets and asteroids will open you up to a whole new world that you never knew existed.

Translated from Greek, “comet” means “long-haired,” since ancient people associated a star with a long tail with hair blowing in the wind.

Comets are dirty ice

A comet's tail only forms when it is in close proximity to the Sun. Far from this celestial body, comets appear as icy, dark objects.

90% of a comet is ice, dirt and dust. In the center is a stone core. As it approaches the Sun, the ice melts, forming a dust cloud behind it. This is the tail we see.

Incredible amount

The smallest comets reach a core diameter of 16 km. The largest recorded is 40 km. The length of the tails can be very long. For example, comet Hyakutake's tail length was 580 million km.

A cluster of comets can number in the trillions. This is exactly what is found in the Oort Cloud, a cluster surrounding the Solar System. Within the solar system, astrologers count at least 4,000 comets.

Jupiter, as the largest planet in the solar system, is capable of changing the direction of comets by the force of its gravity. So, one day comet Shoemaker-Levy 9 crashed into the atmosphere of Jupiter.

Shapeless asteroids

Cosmic bodies form a spherical shape under the influence of their gravity. Asteroids are too small to form a sphere, so they look like ellipsoids or dumbbells.

Integrity of form is rare for an asteroid. More often it is a pile of compounds, which is held by its own gravity. The accumulations contain coal, stone, iron, and volcanic materials.

The diameter of the largest asteroid, Caecesere, is 950 km.

If an asteroid enters a planet's atmosphere, it is a meteor. If it falls to the ground, then it is a meteorite.

Is there a threat to us?

Asteroids pose a potential threat to the planet, but modern technology can easily prevent this.

To imagine how an asteroid falls onto the surface of the planet, you can look. Interesting fact - the Earth can be destroyed with just one meteor with a diameter of 1 km.

Artem Novichonok,
Researcher at the Petrozavodsk State University Observatory,
discoverer of two comets and several dozen asteroids
“Trinity Option” No. 21(165), October 21, 2014

Comets are one of the types of small bodies in the Solar System. They owe their name to the characteristic tails that “bloom” near the Sun. In Greek κομήτης means “hairy”, “having long hair”. Even the astronomical symbol for a comet (☄) has the shape of a disk, from which three lines extend, like hair.
The periods of revolution of comets around the Sun range over a wide range - from several years to several million years. Based on this, comets are divided into short- and long-period. The orbits of the latter are highly elongated, the minimum possible distance of the comet from the Sun can practically coincide with the surface of the star, and the maximum can be tens of thousands of astronomical units.
The main part of a comet is the nucleus. The size of the nuclei is relatively small - up to several tens of kilometers. The cores consist of a loose mixture of rocks, dust and fusible substances (frozen H 2 O, CO 2, CO, NH 3, etc.). Comet nuclei are very dark - they reflect only a few percent of the light falling on them.
As a comet approaches the Sun, the surface temperature of its core increases, causing ice of different compositions to sublimate. The coma (atmosphere) of the comet is formed, which, together with the nucleus, makes up the head of the comet. The size of the coma can reach several million kilometers.
When approaching the Sun, the comet also forms a tail, consisting of coma particles moving away from the nucleus. There are two types of tails: ion (gas) tails, which are always directed in the direction opposite to the Sun due to the action of the solar wind, and dust tails, “spreading” along the comet’s orbit with relatively small deviations. The length of a comet's tail can reach hundreds of millions of kilometers.
As a result of cometary activity, a fair amount of small celestial bodies - meteor particles - remain in the comet's orbit. If the comet's orbit is close enough to the Earth's orbit, a meteor shower can be observed - many meteors ("shooting stars") visible in a short period of time. During heavy meteor showers, thousands of meteors can be observed per hour.
Since comets are constantly losing matter, they cannot exist in the active phase for a long time and, over time, disintegrate into fragments, completely turn into interplanetary dust, or, having lost the supply of near-surface fusible substances, become inert asteroid-like objects.
Every year, dozens of comets are discovered coming to us from the outskirts of the solar system. Consequently, there (at distances up to 50–100 thousand AU) there is a large reservoir of cometary nuclei - the Oort cloud. It cannot be observed directly, but comets provide compelling evidence of its existence.
In the Middle Ages, comets caused fear among people and were considered harbingers of tragic events in the lives of nations (wars, epidemics) and royalty. And even the appearance of Comet Hale-Bopp in 1997 is notorious for the mass suicides of members of the Heaven's Gate sect.
Very bright comets appear infrequently. But they are certainly among the most beautiful and impressive objects in the sky. It is enough to mention, for example, the Great Comet of 1861, C/1995 O1 (Hale-Bopp), which was easily observed even in cities in the spring of 1997, or comet C/2006 P1 (McNaught), which was observed in January 2007, including in during the daytime, and at dusk it showed a huge fan-shaped tail.

Interesting facts about comets will help study small objects of the solar system. You will discover a lot of new and useful things, so many secrets are kept by the relative silence of the universe, which is in constant movement and development.

A comet is a cosmic body that exists within the Solar System, moving in orbit around the Sun. Comets appeared with the emergence of the solar system four and a half billion years ago..
The name is of Greek origin. “Comet” is a Greek word that means “long-tailed,” since this body was so anciently associated with people whose hair fluttered in a strong wind. The closest point of the orbit in relation to the Sun is perihelion, the farthest point is aphelion.
Comet - dirty snow. Chemical composition: water, methandrostenolone, frozen ammonia, dust, stones, space debris. The tail part appears when it is closest to the Sun. At a considerable distance it looks like a dark object, representing a clot of ice. The central part is represented by a stone core. It has a dark surface, its composition is precisely unknown.
As the comet approaches the Sun, it heats up and melts. Melting ice as it approaches the sun leads to the formation of a dust cloud, which creates a tail effect. When approaching the luminary, the body heats up, causing the process of sublimation. When ice is close to the surface, it heats up and creates a jet, erupting like a geyser.
There are many comets. The smallest of them has a core with a diameter of sixteen kilometers, the largest - forty. The size of the tail reaches enormous sizes. Hyakutake has a tail of five hundred and eighty million kilometers. In the “Oort Cloud” that envelops space, several trillion copies can be counted. There are about four thousand comets in total.
Jupiter can influence the movement of comets. The largest planet is able to influence the direction of movement of these celestial bodies. The planet's gravitational force is so strong that Shoemaker Levy 9 was destroyed when it hit the planet's atmosphere.
Under the influence of gravity, a tailed comet takes on the shape of a sphere.. The asteroid is quite small to form a sphere, resembling a dumbbell shape. Asteroids accumulate in piles, containing materials of various origins. The largest, Casetere, is nine hundred and fifty kilometers in diameter. An asteroid that enters the planetary atmosphere is called a meteor; when it falls to the ground, it is a meteorite.
Comet is a potential threat to earthlings. Our civilization could be destroyed by a meteor with a diameter of one kilometer. Continued research is needed to understand the nature of tailed insects and to design optimal methods of protection against them. Even in ancient times, these bodies were considered a sign that could bring disaster.
Halley's Comet periodically visits the Solar System. In 1910, Comet Halley passed close to the Earth, which enters the solar system every 76 years. Some enterprising businessmen used this fact to increase the number of sales of gas masks, comet remedies, and umbrellas.
Comets usually have two tails. The first, dust, can be observed with the naked eye. The second tail consists of gases, stretching up to three hundred and sixty miles. The ion tail is the result of the influence of the solar wind. The orbit of comets resembles an elliptical shape. As the body approaches the Sun, the icy component begins to heat up, causing evaporation. The gases and dust form a cloud called a coma, which moves behind the body. As it moves towards the star, dust and debris are blown off the body, forming a dust tail.
The farther from the Sun, the more the comet is an ordinary stone block. The gas tail becomes visible under the influence of solar radiation. As it moves away from the Sun, the body cools, leaving only an icy core.
Scientists suggest that comets brought water to Earth. Water could have come to the globe from a comet, as well as many organic substances. They were the means of the origin of life.
Some scientists believe that sixty-five million years ago a large asteroid may have touched the surface, causing the dinosaurs to become extinct.
Comets are subject to extinction or departure from the solar system. They leave the system or melt as they are repeatedly exposed to heat.
Only once a decade can we observe a comet in the sky. The comet's tail can be observed for several days or even weeks.

A comet in the sky is a rare guest. Many interesting facts are known about comets. From time immemorial, people have collected information about celestial bodies and sought to understand their nature, measure their sizes, and understand their structure. The stars appear as small dots, but millions of kilometers separate the curious observer on Earth from the distant star. Without astronomical knowledge, it is impossible to form even an approximate opinion about the size of the celestial body. You will be wrong by several orders of magnitude.

A comet in the sky seems huge next to other celestial bodies. But what are its real dimensions and what is it like?
Any comet consists of 3 parts: the nucleus, the coma and the tail.

Core.
The core is the solid part that contains most of the mass of the celestial body. The size of the core usually varies within a few kilometers. By earthly standards it is a big mountain, but by cosmic standards it is nothing.
Kernel composition:
1. Cosmic dust.
2. Frozen gases.
3. Other solids.

Coma.
Moving along an elliptical trajectory, the comet periodically approaches the Sun, the gases begin to expand and the comet becomes as we see it now. Coma - a cloud of gases around the comet's nucleus. The size of a coma can reach a million kilometers, this is comparable to the size of the Sun. Violent chemical processes occur inside the coma.
The coma and nucleus are the head of the comet, and there is also a tail.

Comet tail.
A cloud of gases, molten by the sun's temperature, begins to dissipate around the comet, and as it moves, this cloud takes the shape of a tail and trails behind it. In the sky we see the tail of a comet, the size of which reaches several solar diameters. The different shapes of comet tails are explained by different gas compositions. Different gases react differently to temperature and have different properties, chemical structures, and expand differently.

Interesting facts about comets, collected in one place:

The word "comet" originates from ancient Greece, meaning "long-haired". Since the Greeks considered them stars with flowing hair.
Jupiter, due to its enormous mass, can influence gravity and therefore change the direction of comets. Very often the trajectory of movement changes in an incomprehensible way, frightening scientists.
These celestial bodies can collide with both stars (the Sun) and planets. Researchers have recorded the collision of comet Shoemaker-Levy 9 with Jupiter.
Strange sounds emanate from the comet, reminiscent of singing. The reason for this phenomenon is the expansion of the gas cloud.
The comet has a specific smell. It can be simulated on Earth by combining together a mixture of various gases (mainly ammonia, methane, hydrogen).
In ancient times they were harbingers of wars and disasters.
Quite often you can observe two tails on a comet - dust and gas (can extend for hundreds of millions of kilometers, for example, the tail of Hyakutaki is 580 million km). This is due to gravity and the difference in the specific gravity of gases and dust.
90% of its mass is concentrated in the core, the length of which can reach 40 km (average - 16 km).
In deep space, a comet looks like an ordinary block of ice. The tail appears only when approaching the Sun.
Once every 10 years, a celestial body can be seen with the naked eye.
In 1910, Halley's tail hit the Earth.
The first to document the passage of Halley's Comet were the Chinese in 240 BC.
Scientists have determined that there are more than two million comets in the Solar System.
At the moment, 4 thousand bodies are registered.
In 2014, the first landing of an artificial apparatus on the nucleus of the comet Churyumov-Gerasimenko was carried out. It took 9 years to get closer.