Meteorites are the oldest known minerals (4.5 billion years old), so they should preserve traces of the processes that accompanied the formation of the planets. Until samples of lunar soil were brought to Earth, meteorites remained the only samples of extraterrestrial matter. Geologists, chemists, physicists and metallurgists have been collecting and studying meteorites for more than 200 years. From these studies the science of meteorites emerged. Although the first reports of meteorite falls appeared a long time ago, scientists were very skeptical about them. Various facts led them to finally believe in the existence of meteorites. In 1800–1803, several famous European chemists reported that the chemical composition of "meteor rocks" from different impact sites was similar, but different from the composition of earthly rocks. Finally, when in 1803 a terrible “rain of stones” broke out in Aigle (France), littering the ground with fragments and witnessed by many excited eyewitnesses, the French Academy of Sciences was forced to agree that these were indeed “stones from the sky.” It is now believed that meteorites are fragments of asteroids and comets.
Meteorites are divided into “fallen” and “found”. If a person saw a meteorite fall through the atmosphere and then actually found it on the ground (a rare event), then such a meteorite is called a "fallen". If it was found by chance and identified, which is typical for iron meteorites, then it is called “found.” Meteorites are named after the places where they were found. In some cases, not one, but several fragments are found. For example, after the 1912 meteor shower in Holbrook (Arizona), more than 20 thousand fragments were collected.
Meteorite fall.
Until a meteorite reaches the Earth, it is called a meteoroid. Meteoroids fly into the atmosphere at speeds from 11 to 30 km/s. At an altitude of about 100 km, due to friction with the air, the meteoroid begins to heat up; its surface becomes hot, and a layer several millimeters thick melts and evaporates. At this time it is visible as a bright meteor ( cm. METEOR). The molten and evaporated substance is continuously carried away by air pressure - this is called ablation. Sometimes, under the pressure of air, a meteor is crushed into many fragments. Passing through the atmosphere, it loses from 10 to 90% of its initial mass. However, the interior of the meteor usually remains cold, since it does not have time to warm up during the 10 seconds that the fall lasts. Overcoming air resistance, small meteorites significantly reduce their flight speed by the time they hit the ground and usually go deeper into the ground by no more than a meter, and sometimes they simply remain on the surface. Large meteorites are slowed down only slightly and upon impact produce an explosion with the formation of a crater, such as in Arizona or on the Moon. The largest meteorite found is the iron meteorite Goba (South Africa), whose weight is estimated at 60 tons. It was never moved from the place where it was found.
Every year, several meteorites are picked up immediately after their observed fall. In addition, more and more old meteorites are being discovered. In two places in the east of the state. In New Mexico, where the wind constantly blows away the soil, 90 meteorites were found. Hundreds of meteorites have been discovered on the surface of evaporating glaciers in Antarctica. Recently fallen meteorites are covered with a vitrified, sintered crust that is darker than the interior. Meteorites are of great scientific interest; Most major natural science museums and many universities have meteorite experts.
Types of meteorites.
There are meteorites made of various substances. Some are primarily composed of an iron-nickel alloy containing up to 40% nickel. Among the fallen meteorites, only 5.7% are iron, but in collections their share is much larger, since they are destroyed more slowly under the influence of water and wind, and they are also easier to detect by appearance. If you polish a section of an iron meteorite and lightly etch it with acid, you can often see a crystalline pattern of intersecting stripes formed by alloys with different nickel contents. This drawing is called “Widmanstätten figures” in honor of A. Widmanstätten (1754–1849), who was the first to observe them in 1808.
Stony meteorites are divided into two large groups: chondrites and achondrites. Chondrites are the most common, accounting for 84.8% of all fallen meteorites. They contain rounded millimeter-sized grains - chondrules; Some meteorites are composed almost entirely of chondrules. Chondrules have not been found in terrestrial rocks, but glassy grains of similar size have been found in lunar soil. Chemists have studied them carefully because the chemical composition of chondrules likely represents the primordial matter of the solar system. This standard composition is called the “cosmic abundance of elements.” In chondrites of a certain type, containing up to 3% carbon and 20% water, signs of biological matter were intensively searched, but no signs of living organisms were found in either these or other meteorites. Achondrites lack chondrules and resemble lunar rock in appearance.
Parent bodies of meteorites.
The study of the mineralogical, chemical and isotopic composition of meteorites has shown that they are fragments of larger objects in the Solar System. The maximum radius of these parent bodies is estimated at 200 km. The largest asteroids are approximately this size. The estimate is based on the cooling rate of the iron meteorite, at which two alloys with nickel are obtained, forming Widmanstätten figures. Rocky meteorites were likely dislodged from the surface of small, atmosphereless, cratered planets like the Moon. Cosmic radiation destroyed the surface of these meteorites in the same way as moon rocks. However, the chemical composition of meteorites and lunar samples is so different that it is quite obvious that the meteorites did not come from the Moon. Scientists were able to photograph two meteorites as they fell and calculate their orbits from the photographs: it turned out that these bodies came from the asteroid belt. Asteroids are likely the main sources of meteorites, although some may be particles from evaporated comets.
Short-term flashes that occur in the earth's atmosphere when rapidly moving tiny solid particles invade it are called meteors (sometimes meteors are incorrectly called “shooting stars”). Relatively large particles can cause a very bright flash. Flares whose brilliance exceeds magnitude 5* (this is greater than the maximum brilliance of Venus) are called fireballs. In interplanetary space, many particles of various sizes, the so-called meteoric bodies, move around the Sun. When meteoroids enter the Earth's atmosphere, they can be completely burned or destroyed due to friction. However, the largest of them do not burn completely, and their remains may fall to the surface of the Earth. They are called meteorites. The fall of a meteorite is accompanied by a bright fiery trail.
The search for meteorites on the Earth's surface is a task of exceptional scientific importance, since these are the only celestial bodies that can be studied in detail in laboratories, excluding, of course, those small samples of lunar soil that were delivered to Earth by astronauts and automatic vehicles. Even if your astronomical interests are not related to the study of meteors, you should still be aware of what information observation of these phenomena could bring.
Meteor sighting
Meteors can be seen on any clear night, and under favorable atmospheric conditions, 5-10 meteors per hour can be seen even with the naked eye. These are so-called sporadic meteors, associated with the invasion of individual particles into the earth's atmosphere. Because these particles revolve around the Sun in random orbits, they can randomly appear in the sky in the most unexpected places. In addition to individual particles, entire swarms of them move around the Sun. Many of them are generated by decaying or broken-up comets. Each meteor swarm revolves around the Sun with a constant period, and many of them meet the Earth at certain periods of time. During such periods, the number of meteors increases significantly, and then they talk about meteor showers. Both in outer space and when invading the earth's atmosphere, the particles of a meteor shower move approximately in parallel, but due to the perspective it appears that they are flying out of a limited region of the sky, which is called the radiant. Meteor showers are usually named after the constellations in which their corresponding radiants lie. Data on some of the most famous meteor showers are given in the table. Meteor showers are sometimes named after the comet they are associated with. Thus, the Byulids (or Andromenids) meteor shower got its name from the disintegrated comet Bizla, and the Jacobinids (or Draconids) - from the comets of Jacobini Zinner.
Meteor shower activity is characterized by the number of meteors observed per hour. The numbers given in the table characterize the flow activity that an experienced observer can register under favorable conditions in the direction of the zenith. It is quite obvious that the observed number of meteors depends on the general visibility conditions; moreover, due to the absorption of light in the atmosphere, meteors that flare closer to the horizon appear fainter. Moonlight creates a serious interference when observing meteors, especially during the periods 5-6 days before and after the new moon; For this reason, in some years it is not possible to observe some meteor showers at all. In addition, the intensity of the meteor shower: varies from year to year, and depending on the nature of the distribution of meteor particles in the swarm, these changes can be significant. A compact meteor swarm can generate meteor, or star, showers. An example is the Leonid meteor shower, which caused intense star showers in 1799, 1833 and 1866. (and possibly in earlier historical eras); but it practically disappeared in 1899 and 1932. It is assumed that its disappearance is due to the gravitational influence of Jupiter and Saturn on the orbit of this swarm. However, in 1966, the intensity of the stream turned out to be so high that about 150 thousand meteors were observed in 20 minutes. It was truly an incredible meteor shower. For example, such famous meteor showers as the Quadrantids, Perseids and Gemenids produce no more than 50 meteors per hour. The number of meteors also varies throughout the night. Before midnight, only those meteors are observed that are created by particles “catching up” with the Earth, and therefore the speed of their entry into the atmosphere is low. After midnight, the particles and the Earth move towards each other, and therefore their relative speed is equal to the sum of their speeds. Since the brightness of a meteor depends significantly on the speed of entry of the meteor particle into the atmosphere (the larger it is, the brighter and better visible the meteor is), the observed number of meteors increases after midnight.
Visual observations
Visual observations of meteors are best done in a group. In this case, each observer monitors his own section of the sky, and one person controls the time and records the results of observations. However, even one person can carry out quite interesting things! and valuable observations. Since meteors appear unexpectedly at random intervals, it is necessary to prepare for an observation cycle of 30 minutes each. After each 30-minute observation period, you need to take a short break. Sitting (or lying) motionless for even 30 minutes will quickly make you cold, so try to dress warmly. Don't forget to note the exact start and end times of your observations.
For observations, it is better to choose a section of the sky that is 45° away from the radiant and located as high as possible above the horizon. One person cannot observe the entire sky, so focus all your attention only on the area you have chosen. Prepare a few star charts ahead of time and wrap them in clear plastic (ultimately, you will only need one chart for the area of the sky you have chosen to observe). Before and after each period of continuous observation, estimate the magnitude of the brightest star in the observed portion of the sky. This will make it possible to judge the observation conditions and, if necessary, make corrections to the estimate of the speed of falling meteors.
Ideally, the following data should be noted for each meteor: time of occurrence, path length, type, brightness and various features. When observing very intense meteor showers, obtaining detailed information for each meteor is unrealistic. The information relating to the last three of these points is of greatest interest. We will discuss them in more detail below.
Path length. Revenging the path of a meteor is not difficult. When you see a meteor, string a piece of string along its path, or better yet, “mark” it with a straight stick, this will help you determine the meteor's path among the stars. Estimate the location of the beginning and end of the path and, if possible, note the position of at least one point in the middle of the path. For example: the trajectory began at a point lying at one-third of the distance between the stars y and a Leo, passed near Shva and ended at half the distance between S and y Virgo. Draw the meteor's path on a star chart. Difficulties may arise here, since the trajectory of the meteor appears straight only on star maps made in a special projection. Such maps are not easy to obtain and are difficult to use, since the image of the starry sky on them is highly distorted. On other maps, meteor trajectories are curved, but despite this, if you carefully and accurately plot the position of the starting and ending points of the trajectory, then, if necessary, you can calculate the entire trajectory and orbit of the meteor. When observing a meteor shower, it is enough to note only the constellation through which the meteor passed.
Meteor type. How to determine whether a given meteor is sporadic or whether it is associated with one or another meteor shower. This can be done by mentally tracing (or extending the direction of the pointing stick) the meteor trail “backwards”, seeing if it passes through the radiant of any meteor shower active that night. If the continuation of the meteor trail passes within 4 ° from the radiant, then you can be confident that the meteor belongs to a given shower. Mark the position of the radiant on your star chart. (You must remember that as the Earth moves through the shower of meteor particles, the radiant moves slowly among the stars. Data on the daily movement of the radiant can be found in the corresponding astronomical calendars.) Brightness meteors. By the brightness of a meteor, one can judge the size and speed of movement of the meteor particle. In contrast to estimating the brightness of variable stars, the accuracy of estimating the brightness of meteors is small. Thus, an uncertainty of 0.5 magnitude can be considered quite acceptable here. Such accuracy is not difficult to achieve by learning quickly compare the brightness of a meteor and stars in the observed area of the sky; it is enough to note that the brightness of the meteor lies somewhere between the brightness values of the two comparison stars. Do not try to remember the numerical values of the magnitudes of many stars; it is easier to remember their names (or mark them on a star map), and it is better to look at their magnitudes after observation. Try to choose comparison stars close to the meteor trail, so that the absorption of light equally affects both the meteor and the comparison stars. Certain difficulties may arise when assessing the brightness of bright meteors, since there may not be sufficiently bright stars in the observed area. In this case, it is recommended to visualize the brightness of Sirius (its magnitude is -1.4") or mentally compare the brightness of the meteor with the brightness of Jupiter or Venus (corresponding magnitudes -2.4" and -4.3™).
Special details. Some meteors leave behind a persistent bright trail that lasts for many seconds. When observing such meteors, it is necessary to note the duration of the trail's existence, changes in its shape and position. Since meteors with persistent trails are quite rare, any observations are of considerable interest. With bright meteors, it is sometimes possible to note the color and character of the flash at the end of its trajectory.
Telescopic observations
Observations of meteors can be carried out using telescopes and binoculars, but this requires considerable patience, since the observation area is limited to the small field of view of the telescope. Such observations make it possible to see very faint meteors, which provides information about very small meteoroid particles. It should be borne in mind that meteors may accidentally fall into the field of view of your telescope when observing other celestial objects - variable stars, galaxies, etc. In any case, try to record more details about the meteor's direction, brightness, color and speed, and if possible make a quick sketch of the telescope's field of view and meteor trail.
Bibliography
To prepare this work, materials from the site http://www.astro-azbuka.info were used
A meteor is a particle of dust or fragments of cosmic bodies (comets or asteroids), which, when entering the upper layers of the Earth's atmosphere from space, burn up, leaving behind a strip of light that we observe. A popular name for a meteor is a shooting star.
The Earth is constantly being bombarded by objects from space. They vary in size, from stones weighing several kilograms, to microscopic particles weighing less than a millionth of a gram. According to some experts, the Earth captures more than 200 million kg of various meteoric substances during the year. And about one million meteors flash every day. Only a tenth of their mass reaches the surface in the form of meteorites and micrometeorites. The rest burns up in the atmosphere, giving rise to meteor trails.
Meteoric matter usually enters the atmosphere at a speed of about 15 km/sec. Although, depending on the direction in relation to the movement of the Earth, the speed can range from 11 to 73 km/s. Medium-sized particles, heated by friction, evaporate, giving a flash of visible light at an altitude of about 120 km. Leaving a short-term trace of ionized gas and extinguishes to an altitude of about 70 km. The greater the mass of the meteor body, the brighter it flares. These traces, lasting 1015 minutes, can reflect radar signals. Therefore, radar techniques are used to detect meteors that are too faint to be observed visually (as well as meteors that appear in daylight).
No one observed this meteorite as it fell. Its cosmic nature has been established based on the study of matter. Such meteorites are called finds, and they make up about half of the world's meteorite collection. The other half of the fall, fresh meteorites picked up shortly after they hit Earth. These include the Peekskill meteorite, with which our story about space aliens began. Falls are of greater interest to specialists than finds: some astronomical information can be collected about them, and their substance is not altered by terrestrial factors.
It is customary to name meteorites based on the geographical names of places adjacent to the place where they fell or were found. Most often this is the name of the nearest populated area (for example, Peekskill), but prominent meteorites are given more general names. The two biggest falls of the 20th century. occurred on the territory of Russia: Tunguska and Sikhote-Alin.
Meteorites are divided into three large classes: iron, stony and stony-iron. Iron meteorites are composed primarily of nickel iron. A natural alloy of iron and nickel does not occur in terrestrial rocks, so the presence of nickel in pieces of iron indicates its cosmic (or industrial!) origin.
Nickel iron inclusions are found in most stony meteorites, which is why space rocks tend to be heavier than terrestrial rocks. Their main minerals are silicates (olivines and pyroxenes). A characteristic feature of the main type of stony meteorites, chondrites, is the presence of rounded chondrule formations inside them. Chondrites consist of the same substance as the rest of the meteorite, but stand out on its section in the form of individual grains. Their origin is not yet entirely clear.
The third class of stony-iron meteorites are pieces of nickel iron interspersed with grains of stony materials.
In general, meteorites consist of the same elements as terrestrial rocks, but combinations of these elements, i.e. minerals may also be those that are not found on Earth. This is due to the peculiarities of the formation of bodies that gave birth to meteorites.
Among the falls, rocky meteorites predominate. This means that there are more such pieces flying in space. As for the finds, iron meteorites predominate here: they are stronger, better preserved in terrestrial conditions, and stand out more sharply against the background of terrestrial rocks.
Meteorites are fragments of small asteroid planets that inhabit mainly the zone between the orbits of Mars and Jupiter. There are many asteroids, they collide, fragment, change each other’s orbits, so that some fragments, in their movement, sometimes cross the Earth’s orbit. These fragments give rise to meteorites.
It is very difficult to organize instrumental observations of meteorite falls, with the help of which their orbits can be calculated with satisfactory accuracy: the phenomenon itself is very rare and unpredictable. In several cases this was done, and all orbits turned out to be typically asteroidal.
Astronomers' interest in meteorites was primarily due to the fact that for a long time they remained the only examples of extraterrestrial matter. But even today, when the substance of other planets and their satellites becomes available for laboratory research, meteorites have not lost their importance. The substance that makes up the large bodies of the Solar System underwent a long transformation: it melted, was divided into fractions, and solidified again, forming minerals that no longer had anything in common with the substance from which everything was formed. Meteorites are fragments of small bodies that have not gone through such a complex history. One of the types of meteorites, carbonaceous chondrites, generally represent weakly altered primary matter of the Solar System. By studying it, experts will learn from what large bodies of the solar system were formed, including our planet Earth.
Meteor shower
The main part of meteoric matter in the Solar System revolves around the Sun in certain orbits. The orbital characteristics of meteor swarms can be calculated from observations of meteor trails. Using this method, it was shown that many meteor swarms have the same orbits as known comets. These particles can be distributed throughout the orbit or concentrated in separate clusters. In particular, a young meteor swarm can remain concentrated near the parent comet for a long time. When, while moving in orbit, the Earth crosses such a swarm, we observe a meteor shower in the sky. The perspective effect gives rise to the optical illusion that meteors, which are actually moving on parallel trajectories, appear to be emanating from a single point in the sky, which is commonly called the radiant. This illusion is the perspective effect. In reality, these meteors are generated by particles of matter entering the upper atmosphere along parallel trajectories. These are a great number of meteors observed over a limited period of time (usually a few hours or days). Many annual flows are known. Although only some of them generate meteor showers. The Earth very rarely encounters a particularly dense swarm of particles. And then an exceptionally strong shower could occur, with tens or hundreds of meteors every minute. Typically a good regular shower produces about 50 meteors per hour.
In addition to many regular meteor showers, sporadic meteors are also observed throughout the year. They can come from any direction.
Micrometeorite
This is a particle of meteorite material that is so small that it loses its energy even before it could ignite in the Earth's atmosphere. Micrometeorites fall to Earth as a shower of tiny dust particles. The amount of substance that falls on Earth annually in this form is estimated at 4 million kg. The particle size is usually less than 120 microns. Such particles can be collected during space experiments, and iron particles, due to their magnetic properties, can be detected on the surface of the Earth.
Origin of meteorites
The rarity and unpredictability of the appearance of meteorite material on Earth causes problems in its collection. Until now, meteorite collections have been enriched primarily by samples collected by random eyewitnesses of falls or simply curious people who paid attention to strange pieces of matter. As a rule, meteorites are melted on the outside, and their surface often bears a kind of frozen regmaglypt ripple. Only in places where heavy meteorite showers fall does a targeted search for samples bring results. True, recently places of natural concentration of meteorites have been discovered, the most significant of them in Antarctica.
If there is information about a very bright fireball that could result in a meteorite fall, you should try to collect observations of this fireball by random eyewitnesses over the largest possible area. It is necessary for eyewitnesses from the observation site to show the path of the car in the sky. It is advisable to measure the horizontal coordinates (azimuth and altitude) of some points on this path (start and end). In this case, the simplest instruments are used: a compass and an eclimeter, a tool for measuring angular height (this is essentially a protractor with a plumb line fixed at its zero point). When such measurements are made at several points, they can be used to construct the atmospheric trajectory of the fireball, and then look for a meteorite near the projection on the ground of its lower end.
Collecting information about fallen meteorites and searching for their samples are exciting tasks for astronomy enthusiasts, but the very formulation of such tasks is largely associated with some luck, luck that is important not to miss. But observations of meteorites can be carried out systematically and bring tangible scientific results. Of course, professional astronomers armed with modern equipment also do this kind of work. For example, they have radars at their disposal, with the help of which meteors can be observed even during the day. And yet, properly organized amateur observations, which also do not require complex technical means, still play a certain role in meteorite astronomy.
Meteorites: falls and finds
It must be said that the scientific world until the end of the 18th century. was skeptical about the very possibility of stones and pieces of iron falling from the sky. Reports of such facts were considered by scientists as manifestations of superstition, because at that time no celestial bodies were known, the fragments of which could
Each meteorite that falls to Earth increases the chances of finding answers to many questions about the origin of the Universe and the origin of life on Earth. These cosmic messengers several times led to the apocalypse on our planet. The threat of Armageddon from a collision with a heavenly stone arises every few decades. Below are 15 interesting facts about meteorites:
- Meteorites are considered only those cosmic bodies that have reached the surface of the Earth, and did not burn up in the layers of its atmosphere or fly back into outer space.
- According to rough calculations, about 5–6 tons of celestial bodies fall to Earth every day. And per year this figure is 2,000 tons. The weight of individual specimens ranges from several grams to hundreds of kilograms and even tens of tons.
- The largest crater (astrobleme) from a cosmic body falling to Earth is located in Antarctica and is called Wilkes Earth Crater. Its diameter is 500 km. The meteorite that formed this crater is believed to have fallen 250 million years ago and caused the Permian-Triassic extinction event of 96% of marine and 70% of terrestrial life on our planet. This crater was discovered in 1962. The second largest astrobleme is located in Canada on the shores of Hudson Bay. Its diameter is 440 km.
- The largest and oldest scientifically proven astrobleme with a funnel diameter of 300 km is located in South Africa. The city of Vredefort is located in the crater, which gave its name to the crater. The fall of the celestial body occurred 4 billion years ago.
- The most famous meteorite crater is the Arizona one.. It is located in the USA in the state of Arizona. This crater has a diameter of 1200 meters and a depth of 230, with the edges protruding upward by 46 meters. The Arizona astrobleme was formed 50,000 years ago from the fall of a cosmic body with a diameter of 50 meters, weighing 300,000 tons and flying at a speed of 50,000 km/h. Compared to the atomic bomb dropped on Hiroshima, the explosion in Arizona was 8,000 times more powerful.
- In the 18th century, the Paris Academy of Sciences considered meteorites to be stones of terrestrial origin that are formed from lightning.
- Due to the enormous speed (11 – 72 km/s) of meteorites with which they enter the Earth’s atmosphere, the cosmic body is destroyed (burned and blown away by a flow of atmospheric gases). Therefore, an insignificant part of them reaches the surface. From a multi-ton block, several kilograms may remain.
- When a meteorite breaks into pieces in flight, a meteorite shower can form.. Particularly large celestial bodies can cause catastrophic consequences with meteor showers.
- The largest cosmic body found is the Goba meteorite. It fell to Earth 80,000 years ago in Namibia. The low speed of the fall allowed a large part to survive. Its weight is 66 tons, and its volume is 9 cubic meters. It consists of 84% iron and 16% nickel with an admixture of cobalt. According to assumptions, the initial mass of the meteorite body upon contact with the Earth's surface was 90 tons. But impact, time, vandals and explorers left only 60 tons.
- The Goba meteorite is the largest piece of naturally occurring iron on Earth..
- All cosmic bodies that fell to Earth are divided into three groups according to their composition: iron (6% of falls), stone (93% of cases) and iron-stone.
- Stone meteorites contain traces of organic compounds of unearthly origin. Therefore, there is a theory according to which life was brought to Earth from space.
- Even rocky meteorites are magnetic. This is explained by the presence of nickel iron in their structure
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- There are known cases of cosmic bodies hitting people and the death of a person from the consequences of a shock wave caused by the fall of a cosmic body.
- In 1969, the oldest meteorite in the solar system, the Allende meteorite, fell and shattered in Mexico.. Of the estimated 5 tons, it was possible to collect 3. Among other things, Allende is the largest carbonaceous meteorite found on Earth.
In addition to the planets, many other celestial bodies move around the Sun, the sizes of which are sometimes only 5-10 km. They often find themselves in the path of the Earth. Flying into our planet at high speed, they heat up. In this case, we see meteors flying across the sky. Rocks that fall to Earth are called meteorites. They always fell to Earth. Their fall was described by ancient scientists and Chinese chroniclers, Slavic monks and. New research methods have shown that some of the stone meteorites found fell on our planet over 10 thousand years ago.
The fall of meteorites is accompanied by the appearance of fireballs in the sky - fireballs. These are meteorites with a shell of hot objects surrounding them. The bolide sweeps across the sky, illuminating the area for tens and even hundreds of kilometers.
Meteorites, attracted to the Earth, are heated by friction with the air as they pass through the atmosphere. Some of them burn out before reaching the Earth. The larger the meteors, the less their atmosphere slows them down and the faster they fall to the ground. But such meteorites, fortunately, rarely fall. The only strong, explosive meteorite fall that occurred in human memory happened in 1908 in Podkamennaya Tunguska. As it later turned out, the fiery body fell among the nomads engaged in hunting and reindeer herding. Fires broke out in many places, huts shook and shook, glass flew out of windows, plaster fell off the ceilings. All this was accompanied by a deafening roar, heard over a radius of thousands of kilometers.
Meteorites have also been found in other countries.