What do meteors and meteorites have in common? Major meteor showers. Stars and constellations
Explanatory note.
intellectual game “There on unknown planets” for students in grades 5-9.
MKOU "Yazykovskaya secondary school" is a small school. Therefore, students in grades 5-9 are invited to conduct extracurricular activities.
Brief summary of the work: the work was carried out according to the principle of the television program “Own Game”. The game allows you to repeat the material studied on the topic “Space” and promotes the development of cognitive interest in the subject. Rules of the game: questions are played on a specific topic and are arranged according to difficulty level from 10 points to 50. 2 teams take part in the round. The game is played on five themes. Points are added up for a correct answer, and deducted for an incorrect answer. If a team answers incorrectly, the other team has 20 seconds to think about the answer.
Predicting the maximum of known meteor swamps is inappropriate and unreliable. Why is this so when we know that the mother's body is drunk? Young meteor swarms are active for a few hours at most, while older meteor swarms are active for several weeks. Young swarms are also much more active than older ones, whose currents, with gravitational and other disturbances, spread and “tingle.” The meteor current can be completely measured after a certain period of time.
Meteors that do not belong to the meteor grove are called sporadic meteors or crooked spores. These are meteors that may be fragments of asteroid sirens or the rest of an old meteor shower, but at a very low frequency, it mixes with the sporadic backgrounds.
On the second slide of the presentation there is a table for choosing a topic and the “cost” of the question. By selecting a question (for example, “planets” for “40”) and clicking on “ 40 ", go to the corresponding slide. After the player answers and demonstrates the illustrated correct answer, we return back to the table along the arrow.
Game “There on Unknown Planets”
The Czech Republic has a number of important primates in meteor surveys. According to the 10 snows from the fireball, four meteorites with a total weight of 5.6 kg were found under the leadership of Zatek Sepleh and registered as a meteorite in astronomy. The discovery of the Pribram meteorite was important primarily because the meteorite was “fresh.” It was not contaminated or even evaded like old and oxidized meteorites, so it was possible to determine its exact original chemical composition.
Later, some "competitive" Czechoslovakian fire brigade became a meteorite site in Antarctica in the Allan Hills area. The meteorites here are not fresh, but they are perfectly preserved. Today there are meteorite collections that have the same chemical composition as rocks from Mars or rocks from some asteroids.
Goals:
Introduce students to the history of space exploration and the first astronauts, cosmonauts Tula region, expand your horizons by popularizing knowledge about achievements in the field of astronautics.
Develop cognitive and creative activity. To instill an interest in the study of space and the history of astronautics.
Foster a sense of patriotism and citizenship.
A meteorite is a meteor that landed on the surface of the Earth. However, meteorites affect the surfaces of other planets, moons, and asteroids or comets. A meteor that can "change" on the meteorite can create a small or larger ridge on the surface of the impactor. Depending on the mass and speed of the impact space projectile.
In the case of really large bodies, the impact of a meteorite can have fatal consequences. One theory is that the right meteorite caused the extinction of the dinosaurs. Relatively well-preserved rocks can be found, for example, in the United States of Arizona.
Equipment: computer, multimedia projector, interactive whiteboard, presentation «There on unknown planets."
Progress of the event
Teacher.
Years, decades, centuries will pass, people will forget the dates of wars and revolutions, but this day will always be remembered, and I think that this particular day, April 12, in the near future will become a red holiday date for all future centuries. After all, it was from this day – April 12, 1961 – that man began space exploration.
We don't have to go to the United States to see the benefits of meters. He stays in the evening when the Moon will shine in the hands of an ordinary bastard and shuffle him to this strange satellite Earth. All the dolls on its surface, called terraces, were dug only by such space projectiles - meteorites. In these cases, however, there is no longer a house of memorable origin. The largest of them even created a lunar swamp, these dark surfaces on the surface of the Moon.
Types of meteorites by chemical composition
The chemical composition of such aircraft and terrestrial planets. Gaseous chondrites - charcoal chondrites are a chemical composition similar to type C achondrite asteroids - similar to Earth's induction; meteorites believed to originate from the Moon or Mars. Sidity is usually iron and nickel. . Individual meteorite groups still perform many subgroups, but this is beyond the scope of this review.
Ah, this day is the twelfth of April,
How he swept through people's hearts!
It seemed as if the world had involuntarily become kinder,
I was shocked by my victory.
What kind of universal music he thundered,
That holiday, in the colorful flames of banners,
When the unknown son of the land of Smolensk
Was adopted by the Earth-planet.
Student 1.
Perhaps each of us has already seen the phenomenon of light, which we call the starry sky. The elders can remember another sign of this heavenly phenomenon, namely: the flight, the tears of St. John the Baptist. Laurel, or perhaps the most common name, "shooting star". It is basically a small body, a few millimeters in size, passing through our solar system at relatively high speeds. Typically this can be tens of kilometers per second. We call it a meteoroid.
They moved such a body through the atmosphere, colliding with molecules in the air. It is heated to such a high temperature until it vaporizes and ignites. Small bodies pass through the atmosphere through the entire atmosphere. Large bodies evaporate only partially, and their remains fall to the surface. We call these bodies meteorites.
Since ancient times, the mysterious world of planets and stars has attracted the attention of people, attracting them with its mystery and beauty.
According to ancient wisdom:
Two things amaze us most of all - the stars above our heads and the conscience within us...
Student 2.
Previously, a long time ago, when people were just beginning to recognize the Earth, they imagined it as an inverted bowl, which rests on three giant elephants, standing importantly on the shell of a huge turtle. This miracle turtle swims in the sea-ocean, and the whole world is covered with a crystal dome of the sky with many sparkling stars.
There are nights throughout the year in which more meteors can be seen in the sky than normal nights. This is due to the fact that the Earth crosses the path of several comets and asteroids, in which meteoroids occur in large quantities. We're talking about meteor swarms. Watching the swarm, we see that the meteors fly out from one point, the so-called radiant one. The frequency of meteors can reach even high values under certain conditions, so we cannot calculate it. At that time, we observe tens of hundreds of meteors in the sky at the same time.
This phenomenon was called a meteor shower. Meteor shower is relatively a rare occurrence, but it allows photographers to have a unique photographic image. You can read in the literature that getting a good meteor image is not a problem for the amateur. During the Great Meteor Swarm, you can aim your camera at the sky, open the screen, focus and expose. Unfortunately, this statement is not really consistent. The methods for capturing meteors may seem simple, but chances are the picture will soon be caught by a satellite or aircraft flying over a clear meteor.
Student 3.
Several thousand years have passed since then. Many generations of kind and smart people have grown up on our Earth. They built ships and, having completed round the world travel, learned that the Earth is a ball. And astronomers have proven that the Earth flies in space, revolving around the Sun, making one revolution around its axis per year.
Teacher
Meteor photography is affected by a number of conditions, including light pollution in the sky or the nature of the phenomenon itself. The passage of a body through the atmosphere takes a fraction of a second, and in extreme cases, several seconds. To capture meteors, it is best to focus on the maximum frequencies of each meteor swarm. Data on the activity of meteor swarms can be found, for example, in the Astronomical Yearbook. Very beautiful meteor images can be made with long exposures and a wide angle lens.
If we have a wide field of view and expose an area near radiant, the meteors will be drawn as lines that point from one point. Relevant meteor swarms include the Leonid meteor swarm, which has a very short and sharp maximum.
But man has always been attracted by space.
“Humanity will not remain forever on Earth, but in pursuit of light and space, it will first timidly penetrate beyond the atmosphere, and then conquer the entire solar space.”
Konstantin Eduardovich Tsiolkovsky
And now... Start! (video clip)Teacher And now I invite 2 teams to take part in the game “There on Unknown Planets”. The game is played according to the principle of the television program “Own Game”.
To get a simple meteor photo, basic equipment is all you need. The highest demands are placed on the quality of the lens and camera mechanics. The camera must be able to exchange lenses of different focal lengths and, of course, be able to set long exposures. Caution should be exercised with electronically controlled cameras which, when exposed for long periods of time, will cause the batteries to drain quickly during the winter months. In addition to the battery problem, you may have trouble turning off auto exposure, aperture, or shutter speed modes.
Themes:
Russian cosmonauts, Solar system, space exploration, planets, stars and constellations
Space exploration. 1. Who is the founder of astronautics? Answer: Konstantin Eduardovich Tsiolkovsky
2. Who was called the Chief Designer in our country? Answer: Sergei Pavlovich Korolev
3. In honor of what event is Cosmonautics Day celebrated? Answer: in honor of the flight of Yuri Gagarin (04/12/1961)
Each camera body should also be a trigger wire, which prevents hand shake from being transmitted to the camera when the camera shutter is pressed. Another indispensable tool is a rigid photophonic tripod and fairly sensitive photographic material. At the same time, it is recommended to use a heated lens to the lens, which prevents it from getting wet.
However, Retail should not interfere in the field of view. If we have a digital SLR camera, long exposures can be replaced by a series of shots with shorter exposures and stacked on them. The photo was taken with a full-frame camera that displays the entire night sky, including the Milky Way.
4. What was the name of the first manned spacecraft? Answer: East
5. When was the first satellite launched? Answer: October 4, 1957
Sun, Earth and Moon
1. How many stars are there solar system? Answer: one - the Sun 2. In what phase of the Moon is it possible to observe a Solar Eclipse? Answer: on the new moon. 3. How long will a match burn on the Moon? Answer: it won’t burn, there is no oxygen. 4. Is it possible to navigate on the Moon using a compass? Answer: no, the Moon does not have its own magnetic field 5. What does the sky look like on the Moon? Answer: black
From the above it is quite clear that the passage of a meteorite through the atmosphere is relatively fast. And not every meteor is bright enough to be captured by photographic emulsion. Exceptionally, we can observe a meteor passage with a magnitude greater than -4 mag. We call such a meteorite a fireball.
Firefighting is often accompanied by other light effects, such as its explosion and subsequent separation into several components, or a light trail left by the atmosphere. To capture a meteor on photographic emulsion, it is necessary to use the most sensitive film with a very light lens combination, since the meteor passage takes a tenth of a second. Exposure time is limited by observation conditions at the site and can range from five to ten minutes. To show the widest field of view, wide-angle lenses or lenses are used.
2. The first female cosmonaut Answer: Valentina Tereshkova 3. He was the second to go into space after Gagarin. Answer: German Titov 4. Commander of the Soyuz-11 crew, which made the first docking with the Salyut orbital station Answer: Grigory Dobrovolsky 5. He designed the Soyuz spacecraft, the Mir orbital station. And in 1964, he made the first group flight into space on the Voskhod-1 spacecraft. Answer: Konstantin Feoktistov
As a last resort, we can use the lens to image the entire sky. Another way to help with viewing the entire sky is to place the camera above a convex spherical mirror. Using longer flashes is not suitable because we cannot capture all of the meteor light unless we capture the area directly in the radiant one.
The meteor trail captured by photographic material is quite long. However, in the first tests we will find that the success rate of capturing a meteor trail improves when using a focal length lens that is not too short, since a lens with a shorter focal length is usually lower than the primary lens and the incident light is reduced with the same aperture take off.
Planets 1. How many satellites does Mars have? Answer: two - Phobos and Deimos. 2. Which planet has virtually no atmosphere? Answer: on Mercury 3. Which planet rotates “lying on its side”? Answer: Uranus. 4. What is the difference between a meteor and a meteorite? Answer: a meteor is the phenomenon of the passage of a cosmic body through the earth’s atmosphere, a meteorite is a cosmic body that has reached the surface of the Earth. 5. What is an asteroid? Answer: small planet.
Very wide-angle lenses are less bright, with a luminosity of about 2.8 at best, instead of 1.8 or 1.4 as is the case with basic 50mm lenses. We will have the most success using a lens with a focal length of 28 to 50mm and a lens brightness of 1.8 to 1. Another way to help with the lack of light is to use a focal length reducer or use a multi-camera unit with relatively high brightness and a smaller field vision and create a photographic mosaic from several cameras.
However, the higher the sensitivity of the photographic material, the larger the grain size. Therefore, it is not practical to preserve the quality of the film. The problem with every photographic material is the exposure time, because no manufacturer calculates the exposure for several minutes. Another disadvantage of individual photographic materials of different brands with the same sensitivity is the different behavior at different exposure lengths. The duration of exposure is determined primarily by viewing conditions and light pollution.
Stars and constellations
1. A star that indicates the direction north. Answer: Polar
2. Deneb – α constellation... Answer: Cygnus
3. The constellation in which the variable star Algol is located. Answer: Perseus
4. The star is a red giant located in the constellation Taurus. Answer: Aldebaran
5. The star, from the Latin translation of whose name the word “vacation” comes. Answer: Sirius
In places where there are excellent viewing conditions, we can also use a 30-minute exposure. We can see the qualities of the observing conditions after creating photographic material, which must be sufficiently dark. Meteor photography is probably the only area of photography where the Schwarzschild phenomenon is useful. Allows long exposure without overexposed background while maintaining the high sensitivity needed to capture meteors.
Fixed tripod or parallax
The easiest way to capture high-quality meteor images is to use a solid tripod. Photos taken from a solid tripod with a longer exposure capture the meteor as a line against a starry background. Unfortunately, this star background displays the star image as part of the circles. The length of the circle parts depends on the length of the exposure. Therefore, a problem may arise when identifying the meteor path coordinates. If we use parallax or simple clockwork for photography, we will avoid the problem of determining the meteorite coordinates of the meteor's flight, since the stars will appear as points.
Teacher: So, the game is over. April 12, 1961 is the day of the flight of the world's first cosmonaut, Russian citizen Yuri Gagarin. April 12 has become a major national holiday in honor of cosmonauts, designers, engineers, office workers and workers who create rockets, spaceships and artificial Earth satellites.
Heroes will rush to the stars again,
And they will live from century to century.
He is the First
Like first love
And in memory
And in the human heart.
Teacher: In the meantime, the jury is summing up the results, we will listen to the guys who prepared reports about the cosmonauts of the Tula region.
1st student:
Khrunov Evgeniy Vasilievich.
16th cosmonaut of the USSR/Russia, 38th cosmonaut of the world.
Born 09.10.1933 in the village of Prudy, Volovsky district, Tula region. In 1953 he graduated from the military aviation school. After graduating from the Bataysk Military Aviation School in 1959, he served in the aviation units of the Soviet Army. In the cosmonaut corps since 1969 (first set). In 1968 he graduated from the Air Force Engineering Academy. Made 1 flight into space.
1st flight: 01/15-17/1969 as a research engineer (launch on the Soyuz-5 spacecraft, the Soyuz-5 spacecraft docked with the Soyuz-4 spacecraft, E.V. Khrunov and A.S. Eliseev went through outer space to spacecraft "Soyuz-4", time in outer space - 37 minutes, return on the spacecraft "Soyuz-4").
2nd student:
Zaletin
Sergey Viktorovich
. Colonel of the Air Force, 392nd cosmonaut of the world, 92nd cosmonaut of Russia.
Born on April 21, 1962 in Shchekino, Tula region, Russia. In 1983 he graduated from Borisoglebsk VVAUL named after. V.P. Chkalov, and in 1994 – the State Academy of Oil and Gas with a master’s degree in environmental management.
In 1983–1990 served as a pilot, senior pilot and air wing commander of the 9th Air Division of the Moscow Military District Air Force.
On August 8, 1990, Sergei Zaletin was enrolled in the cosmonaut corps of the Air Force Cosmonaut Center. In 1990–1992 completed the OKP course, and on March 11, 1992, he was awarded the qualifications of a test cosmonaut.
In 1992–1997 he trained in a group under the Mir program. In 1997–1998 was trained as a commander of the backup crew of EO-26 at the Mir Orbital Complex, and from March 1999 to March 2000. – as commander of the main crew of EO-28.
S. Zaletin made his first space flight from April 4 to June 16, 2000 as the commander of the Soyuz TM-30 spacecraft and the Mir spacecraft under the EO-28 program.
From May to October 2001, Sergei trained as commander of the ISS-EP2 backup crew. On December 10, 2001, he began training as a member of the ISS-EP4 prime crew. This is his second space flight.
Pilot-cosmonaut of the Russian Federation, Hero of the Russian Federation Sergei Zaletin is a military pilot of the 1st class and a cosmonaut of the 2nd class. Has a total flight time of more than 1,350 hours on five types of aircraft.
Sergei is married to Elena Mikhailovna. They have a son, Sergei, born in 1984.
3rd student:
Polyakov Valery Vladimirovich (1942) made his first space flight from August 29, 1988 to April 27, 1989 as the first cosmonaut-researcher of the Soyuz TM-6 spacecraft. And on May 5, 1989, for carrying out a long-term space flight, he was awarded the qualification of an instructor-cosmonaut-researcher of the 2nd class, and later the title of Hero of the Soviet Union (1989), with the presentation of the Order of Lenin and the Gold Star medal. He was also awarded the title of Hero of the Republic of Afghanistan with the Order of the Sun of Freedom (1988, DRA), and was awarded the Order of Officer of the Legion of Honor (1989, France). V.V. Polyakov is a member of the International Association of Space Explorers, a full member of the International Academy of Astronautics, a member of the Main Medical Commission for the Examination of Cosmonauts. Valery Vladimirovich defended his Doctor of Medical Sciences degree and has over 50 publications in domestic and foreign publications devoted to the problems of space biology and medicine.
Teacher: And now the word from the counting commission.
Results of the event:
How was the lesson useful?
What did you like?
What are you thinking about?
What do you remember?
What else would you like to know about?
How many of you would like to fly into space?
Teacher.
"Living and believing is wonderful,
Unprecedented paths lie before us,
Astronauts claim
and dreamers
That there will be apple trees on Mars
blossom….".
Everyone sings the song “And apple trees will bloom on Mars.”
Rewarding.
A meteor is a particle of dust or debris. 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 substances during the year. meteoric matter. 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 Earth's movement, 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, which last 10–15 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 are falls, “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.
Meteorites are usually named after geographical names places adjacent to the place of fall or discovery. Most often this is the name of the nearest settlement(e.g. Peekskill), but prominent meteorites are given more general names. The two most major falls XX 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 round formations inside them - chondrules. 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 - 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 planets - asteroids that mainly inhabit 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 debris small bodies who have not gone through such a complex history. Some 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 “ripple” - regmaglypts. 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 for possible larger 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, fragments of which could fall to Earth. For example, the first asteroids - small planets - were discovered only at the beginning of the 19th century.
The first scientific work to claim cosmic origin meteorites, appeared in 1794. Its author, the German physicist Ernst Chladni, was able to give a unified explanation for three mysterious phenomena: fireballs flying across the sky, melted pieces of iron and stone falling to Earth after the flights and discoveries of strange melted iron blocks in different places Earth. According to Chladni, all this is connected with the arrival of cosmic matter on Earth.
By the way, one of these unusual iron blocks was a multi-pound “kritsa”, taken by Russian academician Peter Simon Pallas from Siberia and which laid the foundation for the national collection of meteorites in Russia. This iron block with grains of the mineral olivine included in it received the name “Pallas iron” and subsequently gave the name to a whole class of stony-iron meteorites - pallastites.
Antarctica
Although meteorites fall all over the globe, they most often end up in the oceans and sink to the bottom. But there are huge barren plains on Earth, in eastern Antarctica blue ice. On these plains there are occasional pieces of rock.
Research of meteorite impact sites
A bright streak in the sky, recorded almost at dusk on August 13, 1999, is not a meteor flash, but a “sunbeam” from a satellite. This satellite, Iridium-52, is one of the Iridium family of digital communications satellites. The "flares" are caused by sunlight reflecting off smooth antennae.
One in 100,000 meteorites that fall to Earth is destructive. Over the past 200 years of observations, 23 meteorites hit homes in the United States, and 4 meteorites in the former USSR.
1511 Genoa (Italy). During solar eclipse there was a meteor shower. As a result, several fishermen and a priest were killed. 1684 Tobolsk (Russia). The dome of the church was pierced as a result of a meteorite falling. 1836 Brazil. A sheep is killed by a meteorite. 1911 Egypt. Fallen meteorite the dog was killed.
On November 12, 1982, in Wethersfield (Connecticut, USA), Robert and Wanda Donahue were sitting in front of the TV in the evening when a blow was heard in the hallway and the sound of crumbling plaster was heard. The elderly couple discovered a hole the size of a human head in the roof and ceiling of the house, and in the kitchen, under the table, a stone meteorite with a diameter of 13 cm and a mass of 2.7 kg. The scientists who arrived on call were not too lazy to even look into the vacuum cleaner with which the owners carried out the cleaning before the arrival of the guests. and found several meteorite fragments there. The meteorite ended up in the collection and was named “Donahue”.
On October 9, 1992, at 8 o'clock in the evening, a stone meteorite weighing 12.3 kg fell in Peekskill (New York, USA) onto the trunk of a car parked in the yard and the impact split into several parts, severely denting the trunk. The young owner of the car ran out to hear the noise. The meteorite was still warm. She informed the nearest university. A few hours later, scientists, collectors, museum staff, the press, representatives of Sotheby's auction, etc. gathered at the house. Scientists confirmed that it was a stone meteorite (chondrite) and the owner received $70,000 for it. So the stone falling from the sky was fortunate.
Chicxulub Crater
A large terrestrial impact crater on the northern coast of the Yucatan Peninsula in Mexico, now largely hidden by sedimentary rocks. It is believed to be associated with an impact event that occurred 65 million years ago, which apparently caused the mass extinction of living creatures, including dinosaurs.
Goba meteorite
The largest known meteorite in the world. Its dimensions are 3x3x1 m. It belongs to the type of iron meteorite and weighs approximately 55,000 kg. It is still at the crash site in Namibia, where it was discovered in 1928. The meteorite is covered with a layer of rusty, eroded material; taking into account erosion, the initial mass of the meteorite should exceed 73,000 kg.
Sikhote-Alin rain
A large meteor shower that fell on February 12, 1947 eastern Siberia. The largest meteorite found weighed 1,745 kg, but it is estimated that thousands of fragments fell to the surface of the Earth, weighing up to 100 tons. Most of them were not found.
Anihito
Most big meteorite from those in museums around the world. This iron meteorite was found by Robert Peary in Greenland in 1897. Weight - 31 tons. Exhibited at the Hayden Planetarium in New York.
Interesting stories
October 9, 1992 America lived in anticipation of Columbus Day: the 500th anniversary of the discovery of the New World by the great navigator was approaching. 18-year-old Michelle Knapp from the small town of Peekskill (New York) was watching TV in the evening. Suddenly she heard a loud noise on the street. The girl got scared and called the police, who found that this time the “intruder” was a space wanderer: next to the Napps’ damaged car lay a melted stone weighing almost 9 kg.
This case is the exception rather than the rule: stones or pieces of iron falling from the sky - they are called meteorites - behave surprisingly peacefully towards people. Only two cases have been reliably recorded
Town of Peekskill
When the Peekskill meteorite flew over the United States in 1992, 16 people managed to film it before it crashed into a car. This spectacular car crossed air space several US states in 40 seconds of his flight until he landed in Peekskill, a suburb of New York.
The most famous meteorite falls
While Colby Navarro was working at the computer, a boulder from outer space crashed through the roof of the house, hit the printer, hit the wall and remained lying next to the catalog box. This happened around midnight on March 26 in the town of Forest Park, Illinois (USA) near Chicago.
Meteorite in Chicago
meteorites hitting people (both without serious consequences), the material damage they caused is also negligible. There is no mysticism in this “friendliness”: a meteorite fall is a rare phenomenon and can happen with equal probability anywhere on the globe. And people still don’t take up much space on their planet. So the heavenly wanderers fall into the oceans, which account for more than 2/3 earth's surface, to vast deserts, forests, polar regions - in full accordance with the laws of mathematical statistics. Therefore, any of us not only practically does not risk being hit by a meteorite, but even has very little chance of seeing it fall.
However, there is no need to despair. Everyone can observe the arrival of cosmic matter on Earth. It is enough to spend at least an hour on a clear night peering into the starry sky, and you will probably notice a fiery line cutting through the sky. This is a falling “star”, or meteor. Sometimes there are a lot of them - whole star showers. But no matter how many of them fly by, the appearance of the starry sky will not change: falling stars have nothing to do with real stars.
In the outer space surrounding our planet, many solid bodies of various sizes move - from dust grains to blocks with diameters of tens and hundreds of meters. The larger the body size, the less common they are. Therefore, dust grains collide with the Earth every day and hourly, and blocks - once every hundreds and even thousands of years.
The effects accompanying these collisions are also completely different. A small body weighing a fraction of a gram, invading the earth’s atmosphere at enormous speed (tens of kilometers per second), heats up from friction with the air and burns up completely at an altitude of 80–100 km. An observer on Earth sees a meteor at this moment. If, however, a larger piece flies into the atmosphere, for example the size of a fist, and, moreover, not with the most high speed, – the atmosphere can act as a brake and extinguish the cosmic velocity before the piece burns out completely. Then its remainder will fall to the surface of the Earth. This is a meteorite. The fall of a meteorite is accompanied by a fireball flying across the sky and thunderous sounds. Few people have ever observed such phenomena. Finally, when the mass of the flying body is even greater, the atmosphere can no longer extinguish all its speed, and it crashes into the surface of the Earth, leaving a cosmic scar on it - a meteorite crater or crater.
If you look at the Moon through a telescope, you will see that its entire surface is literally pitted with such craters - traces of meteorite bombardment to which the Moon was subjected in the past. The Earth also received cosmic impacts in the past (see the article “Asteroid Threat”). Their traces in the form of meteorite craters (sometimes called astroblemes - “star wounds”) remained on the surface of our planet. The most famous of them, the crater in Arizona, is more than 1 km across and was formed 50 thousand years ago. The dry desert climate ensured its good preservation. External traces of other cosmic scars have been largely erased by subsequent geological processes. One of the largest such formations known today is located in northern Siberia. This is the Popigai meteorite crater with a diameter of 100 km.