MOSCOW, February 14 – RIA Novosti. A year ago, on February 15, 2013, residents of the southern Urals witnessed space catastrophe- the fall of an asteroid, which was the first such event in history to cause serious damage to people.
In the first moments, residents of the region spoke about the explosion of an “unknown object” and strange flashes. Scientists spent a whole year studying this event, what they managed to find out at this point - read the RIA Novosti review.
What was it?
A rather ordinary cosmic body fell in the Chelyabinsk region. Events of this magnitude occur once every 100 years, and according to some data, more often, up to five times a century. Scientists believe that bodies approximately ten meters in size (about half the size of the Chelyabinsk body) enter the Earth's atmosphere about once a year, but this happens most often over the oceans or over sparsely populated regions. Such bodies explode and burn on high altitude without causing any harm.
The size of the Chelyabinsk asteroid before the fall was about 19.8 meters, and its mass was from 7 thousand to 13 thousand tons. According to scientists, a total of 4 to 6 tons fell to the ground, that is, about 0.05% of the original mass. Of this amount, no more than 1 ton has been collected at the moment, taking into account the largest fragment weighing 654 kilograms, raised from the bottom of Lake Chebarkul.
Geochemical analysis showed that the Chelyabinsk space object belongs to the type of ordinary chondrites of class LL5. Chondrites are one of the most common types of stony meteorites; about 87% of all meteorites found belong to this type. They are distinguished by the presence in the thickness of rounded grains of millimeter size - chondrules, which consist of partially melted substance.
Expert: the largest fragment of the Chelyabinsk meteorite weighs 654 kgThe exact weight of the largest fragment of the Chelyabinsk meteorite, which was recovered from the bottom of Lake Chebarkul in mid-October 2013, was 654 kg, the director of the company that carried out the operation to lift the meteorite told reporters.Data from infrasound stations indicate that the power of the explosion that occurred during the sharp deceleration of the Chelyabinsk asteroid at an altitude of about 90 kilometers ranged from 470 to 570 kilotons of TNT - this is 20-30 times more powerful than the nuclear explosion in Hiroshima, but more than ten times less than the power of the explosion at the time of the Tunguska disaster (from 10 to 50 megatons).
What made this fall unique was the place and time. This is the first time in history that a large meteorite has fallen in a densely populated area, so never before has a meteorite fallen caused such serious damage - 1.6 thousand people turned to doctors, 112 were hospitalized, windows were broken in 7.3 thousand buildings.
Thanks to this, scientists have obtained a huge amount of data about the event - it is the best documented meteorite fall. As it turned out later, one of the video cameras even captured the moment the largest fragment fell into Lake Chebarkul.
Where did this come from?
Scientists answered this question almost immediately: from the main asteroid belt of the Solar System, the region between the orbits of Mars and Jupiter, where the trajectories of many small bodies pass. The orbits of some of them, in particular, the Apollo and Aten group asteroids, are elongated and can cross the Earth’s orbit.
Thanks to the fact that the flight of the Chelyabinsk bolide was recorded on many videos and photographs, including satellite ones, astronomers could fairly accurately restore its trajectory, and then try to continue this line back, beyond the atmosphere, to build the orbit of this body.
Attempts were made to restore the trajectory of the Chelyabinsk body before the collision with the Earth. different groups astronomers. Their calculations showed that the semimajor axis of the Chelyabinsk asteroid’s orbit was about 1.76 astronomical units (the average radius of the Earth’s orbit), perihelion (the point of the orbit closest to the Sun) was at a distance of 0.74 units, aphelion (the most distant point) - at 2 ,6 units.
With this data in hand, scientists tried to find the Chelyabinsk asteroid in catalogs of previously discovered small bodies. It is known that many already discovered asteroids are “lost” again after some time, and some of them are discovered twice. Scientists did not rule out that the Chelyabinsk object belonged to such “lost” bodies.
His relatives
Although an exact match could not be found, scientists have found several possible “relatives” of the “Chelyabinsk resident.” Jiri Borovichka's team from the Astronomical Institute of the Czech Academy of Sciences calculated the trajectory of the Chelyabinsk body and found that it is very similar to the orbit of the 2.2-kilometer asteroid 86039 (1999 NC43). In particular, the semimajor axis of the orbit of both bodies is 1.72 and 1.75 astronomical units, the perihelion distance is 0.738 and 0.74.
Spanish astronomers Carlos and Raul de la Fuente Marcos (Carlos de la Fuente Marcos, Raul de la Fuente Marcos) analyzed all variants of the orbits of the Chelyabinsk cosmic body and found another possible progenitor of the Chelyabinsk superbolide - asteroid 2011 EO40. In their opinion, the Chelyabinsk asteroid broke away from it about 20-40 thousand years ago. The meteorite, later named "Chelyabinsk", fell on February 15, 2013. Scientists still cannot figure out why some meteorite fragments are completely dark, while others are light inside.
Fragments of the Chelyabinsk cosmic body that fell to earth “told” scientists the story of its life. It turned out that the Chelyabinsk asteroid is the same age as the Solar System. Analysis of lead and uranium isotope ratios showed that its age is about 4.45 billion years.
However, approximately 290 million years ago, the Chelyabinsk asteroid experienced a major catastrophe - a collision with another cosmic body. This is evidenced by dark veins in its thickness - traces of melting of the substance during a powerful impact.
However, scientists believe that this was a very “fast” process. The traces of cosmic particles - the tracks of iron nuclei - did not have time to melt, which means that the “accident” itself lasted no more than a few minutes, stated specialists from the Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences.
At the same time, it is possible that traces of melting could have appeared during the asteroid’s too close approach to the Sun, according to scientists from the Institute of Geology and Mineralogy (IGM) SB RAS.
Exactly five years ago, on February 15, 2013, residents Chelyabinsk region saw a bright flash in the sky. Many mistook it for a fallen plane or satellite and did not immediately recognize that a meteorite had exploded over the region. It split into dozens of fragments, the search for which is still ongoing. Leading researcher at the Department of Lunar and Planetary Research at the Sternberg State Astronomical Institute, Vladimir Busarev, told MIR 24 about why the Chelyabinsk meteorite miraculously survived and how to behave if you suddenly find a fragment of a cosmic body.
- Every year thousands of meteorites fall to Earth. Why did Chelyabinsk turn out to be so popular?
This is the first time we have observed a case where an ordinary chondrite fell to Earth, and in such a large volume. The weight of the fragments that reached the Earth exceeded 650 kilograms. This is a fairly rare type of meteorite, which is why it is considered a find. It is also important that the Chelyabinsk meteorite was found relatively quickly - six months after the fall, and began to be studied immediately. Stones that have lain for some time on the surface of the Earth have less value. They have definitely undergone changes that are characteristic only of terrestrial conditions, but not of cosmic matter. Thus, on the largest fragment of a meteorite that fell into Lake Chebarkul, living microorganisms of terrestrial origin were discovered. But it cannot be said that this prevented research.
- How did these bacteria get there?
The largest fragment of the meteorite lay at the bottom of the lake for six months. It turned out that it had pores through which it was saturated with earthly water, and along with it bacteria penetrated the surface of the fragment. However, we cannot say that the origin of microorganisms is extraterrestrial, because we are dealing with a substance that was contaminated under terrestrial conditions. The Chelyabinsk meteorite has no signs of extraterrestrial life. This can be said with complete certainty, even though not all the fragments have yet been recovered from the bottom of the lake.
- Colleagues from the Ural University presented you with a sample of the Chelyabinsk meteorite. Tell us about it.
It is small, weighing several tens of grams. We studied it in laboratory conditions. We looked at its reflective characteristics and composition of the substance. We were convinced that it was a stone meteorite, it consists of the so-called ordinary chondrite. The iron content in it is small, no more than 20 percent. These types of stony meteorites are quite rare. They have poor "survivability" because they are less able to survive passage through the earth's atmosphere. That is, they are very fragile. In general, all known meteorites have been studied by us only a quarter. Therefore, there is great interest space projects for the delivery of samples from the Moon or Mars. Only original cosmic matter can give full information about the origin of a particular planet of the solar system or an asteroid.
- Was it because of this fragility that the explosion occurred?
Yes, from the fragments of the Chelyabinsk meteorite it is clear that its body is not monolithic, it cracked while flying towards the Earth. If the body had been monolithic, perhaps the explosion would not have occurred, and a fragment of a larger mass would have fallen onto the earth's surface. Eyewitnesses said they heard a series of explosions, but in fact there was only one explosion. The sound simply had a whole spectrum of waves. The acoustic effect was like thunder: at first the sound was weak, then it intensified. People thought there were several explosions. The fact is that meteorite fragments entered the atmosphere at supersonic speed, and there were many of these fragments. This explains the unusual sound effects.
- Why was the meteorite called Chelyabinsk and not Chebarkul?
Initially they wanted to call it Chebarkul. But the fact is that only the largest fragment of a meteorite fell in Chebarkul. The substance, a fragment of which is the Chelyabinsk meteorite, scattered beyond this settlement over a fairly large area. Therefore, the scientific community decided to emphasize in the title that the fall of the cosmic body occurred in the Chelyabinsk region and did not concern only Chebarkul.
- What is known about the cosmic body from which the Chelyabinsk meteorite broke off?
It is approximately 4.5 billion years old. About 300 million years ago it collided with other cosmic bodies. A strong collision led to fragmentation and the formation of a secondary body, which, in turn, was also fragmented. The fact of the collision is confirmed by jadeite - a mineral greenish color, which is part of the Chelyabinsk meteorite. It is formed only when high temperatures and pressure, is a bit like jade, a mineral used to make jewelry.
Particularly enterprising residents of Chelyabinsk have repeatedly tried to sell fragments of the famous meteorite. How do you feel about this behavior?
Scientists, in principle, have a negative attitude towards this type of fraud and urge all people who find meteorites to donate them for research. Thus, fragments of the Chelyabinsk meteorite must first be given to the Chelyabinsk State University. Also in Moscow, at the Vernadsky Institute of Geochemistry and Analytical Chemistry, there is a committee on meteorites. We must understand that scientists always have the opportunity to obtain some valuable information about meteorites. Any such finds are of scientific interest to us, and the state is ready to pay for them.
- Which of the meteorites that fell in Russia is considered the most mysterious?
Perhaps Tunguska. There was no debris left from it, so no one knows exactly what this meteorite was. I can assume that it was a meteorite of a primitive icy composition. The sudden heating in the Earth's atmosphere led to a thermal explosion. If you remember, this explosion was accompanied by a powerful glow. It was as strong as a nuclear explosion. There is still an assumption that it was not a meteorite, but nuclear explosion. But this is not so, because no products of thermonuclear reactions were found at the site. You can learn more about the Tunguska meteorite, but to do this you need to study a large area in the permafrost of the impenetrable taiga using highly sensitive equipment. This is quite difficult to organize. In addition, if any isotopes are discovered there, they need to be studied immediately on the spot. Transporting them is very difficult. If we could conduct a long-term expedition, we would learn something new about the Tunguska meteorite.
At the time of entry into the Earth's atmosphere, the Chelyabinsk meteorite weighed 13 thousand tons and was the size of a seven-story building. Among the meteorites that fell in Russia, it became the largest after Tunguska. Scientists have determined that the meteorite entered the atmosphere at a speed of 19 kilometers per second. Some of the fragments, approaching the Earth, collapsed and burned in the atmosphere. The shock wave knocked out glass in many buildings and destroyed the cladding. About a thousand people received injuries of varying severity. The material damage to the region from the meteorite fall exceeded a billion rubles. The largest meteorite fragment became an exhibit at the State Historical Museum Southern Urals. Everyone can touch it.
Most often, meteorites fall in Antarctica. According to experts, there are about 700 thousand of them scattered on the mainland. The largest meteorite is called Goba, it was discovered in Namibia in 1920. Its weight exceeds 60 tons.
I deliberately paused so as not to create myths and mysteries without more or less reliable facts. Now that such facts already exist, it is time to systematize the information.
Where did the meteorite fall?
So, on the morning of February 15, 2013, at 9.20 local time (at 7.20 Moscow time), a meteoroid entered the Earth’s surface at a very acute angle - that is, a celestial body smaller in size than an asteroid. If such a body reaches the surface of the planet, it is called a meteorite, and if it burns up in dense layers of the atmosphere, it is called a meteor. In this case, the meteoroid exploded in the air at an altitude of approximately 15 to 25 km and its numerous fragments reached the Earth. The largest fragment supposedly fell into Lake Chebarkul, which is located a kilometer from the city of the same name in the Chelyabinsk region (78 km west of Chelyabinsk). The weight of this fragment is believed to be between 200 and 500 kg. In addition, the very next day, enthusiasts of the Ural Federal meteorite expedition began collecting small fragments of the heavenly guest. The total amount of collected fragments is currently about 3 kg. In addition to the vicinity of Lake Chebarkul, fragments were found in the southern suburbs of Chelyabinsk - Pervomaisky, Yemanzhelinka, Deputatsky. Scientists also suggest the possibility of finding fragments also in the area of the village of Shchapino and the village of Travniki.
Consequences of a meteorite fall
The explosion of a meteoroid in the atmosphere caused numerous destructions in Chelyabinsk and its surroundings. Fortunately, there were no deaths, but many people suffered from glass broken by the shock wave. More than 1,600 people received various injuries, of which 69 were so serious that they required hospitalization. At the moment, all the victims have already been discharged from hospitals.
Most of the damage was caused by broken glass (the windows of about 3,000 houses were damaged to one degree or another), but at the Chelyabinsk Zinc Plant the damage was more serious - the roof was destroyed and some walls of the buildings were damaged. In the very first information that began to arrive immediately after the disaster, this particular plant was called the site of the meteorite fall. But now we can say with confidence that the destruction was caused by a shock wave from an explosion equivalent to 100-200 kilotons of TNT. For comparison, the energy of the first atomic bomb, exploded over Hiroshima, was no more than 18 kilotons.
The diameter of the meteoroid at the time of the explosion was approximately 17 m, its weight was about 10 tons, and its speed was 18 km/s.
Immediately after the disaster, they began to calculate the damage, which multiplied exponentially. There were anecdotal situations where people themselves broke the windows in their homes after hearing about compensation for victims of the explosion.
In addition, offers for the sale of meteorite fragments immediately began to appear on the Internet, and the total weight of these “finds” exceeded not only the weight of the one already found at that time, but also the entire meteorite.
Previously, it was proposed to name the meteorite “Chebarkul”, but later settled on the name “Chelyabinsk”.
After the fall of the Tunguska meteorite in 1908 on the territory of our country, only once did we encounter a phenomenon of this magnitude - in 1947 in the Primorsky Territory on Far East A meteorite fell in the Sikhote-Alin mountains total mass about 23 tons. Based on the name of the area, it was called Sikhote-Alinsky.
A compilation of videos filmed by eyewitnesses.
Meteorites have fallen to the ground many times: one fell quite recently - we are talking, of course, about the famous Chelyabinsk meteorite. There are others, no less famous and much larger, the consequences of whose fall were sometimes devastating.
1. Tunguska meteorite
On June 17, 1908, at seven o'clock local time, an air explosion with a power of about 50 megatons occurred in the area of the Podkamennaya Tunguska River - this power corresponds to the explosion of a hydrogen bomb. The explosion and the subsequent blast wave were recorded by observatories all over the world, huge trees on an area of 2000 km² from the supposed epicenter were uprooted, and not a single intact glass was left in the houses of residents. After this, for several more days the sky and clouds in this area glowed, including at night.
Local residents said that shortly before the explosion they saw a huge fireball flying across the sky. Unfortunately, given the year of the incident, not a single photograph of the ball was taken.
None of the numerous research expeditions discovered any celestial body that could serve as a basis for the ball. Moreover, the first expedition arrived in the Tunguska region 19 years after the event described - in 1927.
The event is attributed to the fall of a large meteorite to Earth, which later became known as the Tunguska meteorite, but scientists were unable to detect fragments of the celestial body or at least the matter remaining from its fall. However, in this place an accumulation of microscopic silicate and magnetite balls was recorded, which could not have arisen in this area for natural reasons, so they are attributed to cosmic origin.
It is still unknown exactly what caused the explosion: there is no official hypothesis, but the meteorite nature of the phenomenon still seems most likely.
2. Meteorite Tsarev
In December 1922, residents of the Astrakhan province were able to observe a stone falling from the sky: eyewitnesses said that the fireball was enormous in size and made a deafening noise in flight. Afterwards there was an explosion, and from the sky (again according to eyewitnesses) a rain of stones began to fall - the next day, farmers living in that area found fragments of stones of a strange shape and appearance in their fields.
The rumor about the incident quickly spread throughout Russia: expeditions arrived in the Astrakhan province, but for some reason they did not find any traces of the meteorite fall. They were found only 50 years later when plowing the fields of the Leninsky state farm - a total of 82 chondritic meteorites were found, and the fragments were scattered over an area of 25 km2. The largest fragment weighs 284 kg (now it can be seen in the Moscow Fersman Museum), the smallest is only 50 grams, and the composition of the samples clearly indicates their extraterrestrial origin.
The total weight of the found debris is estimated at 1225 kg, while the fall of such a large celestial body did not cause significant damage.
3. Goba
The largest intact meteorite in the world is the Goba meteorite: it is located in Namibia and is a block weighing about 60 tons and a volume of 9 m³, consisting of 84% iron and 16% nickel with a small admixture of cobalt. The surface of the meteorite is iron without any impurities: there is no other single piece of natural iron of such size on Earth.
Only dinosaurs could have observed Goba's fall to Earth: he fell on our planet in prehistoric times and was buried underground for a long time, until in 1920 it was discovered by a local farmer while plowing a field. Now the site has been given the status of a national monument, and anyone can see it for a small fee.
It is believed that the meteorite weighed 90 tons when it fell, but over the millennia of being on the planet, erosion, vandalism and Scientific research caused its mass to decrease to 60 tons. Unfortunately, the unique object continues to “lose weight” - many tourists consider it their duty to steal a piece as a souvenir.
4. Sikhote-Alin meteorite
On February 12, 1947, a huge block fell in the Ussuri taiga - the event could be observed by residents of the village of Beitsukhe in the Primorsky Territory: as always happens in the case of a meteorite fall, witnesses spoke of a huge fireball, the appearance and explosion of which was followed by a rain of iron fragments, fell over an area of 35 km². The meteorite did not cause significant damage, but it made a number of craters in the ground, one of which was six meters deep.
It is assumed that the mass of the meteorite at the time of entry into the Earth's atmosphere ranged from 60 to 100 tons: the largest of the fragments found weighs 23 tons and is considered one of the ten largest meteorites in the world. There are also several other large blocks formed as a result of the explosion - now the fragments are stored in the Meteorite Collection of the Russian Academy of Sciences and the Khabarovsk Regional Museum named after N. I. Grodekov.
5. Allende
Allende fell to Earth on February 8, 1969 in the Mexican state of Chihuahua - it is considered the largest carbonaceous meteorite on the planet, and at the time of its fall its mass was about five tons.
Today, Allende is the most studied meteorite in the world: its fragments are stored in many museums around the world, and it is notable primarily for the fact that it is the oldest discovered body Solar System, the age of which was accurately established - it is about 4.567 billion years old.
In addition, a previously unknown mineral, called pangite, was found in its composition for the first time: scientists suggest that such a mineral is part of many space objects, in particular asteroids.
An early February morning in 2013 suddenly became tragic for 1,613 residents of Chelyabinsk and its environs. Such large quantity people affected by fallen meteorite There has never been a human population on Earth in history. During the wave, windows were broken in many buildings, trees were broken and people were injured to varying degrees, as a result of which about 1,613 people were recognized as victims, of which, according to various sources, from 50 to 100 people were hospitalized. People who watched the meteorite fall that morning were simply shocked by the events taking place. The first versions of what was happening sounded like: a plane crash, a rocket crash, and even an alien attack...
At the moment, the picture of the events of that tragic morning has been completely restored and it is reliably known when and where the meteorite fell in Chelyabinsk.
How it was
At approximately 9 a.m. on February 15, this “unexpected guest” appeared high in the sky above Chelyabinsk, resulting in a state of emergency being declared in Chelyabinsk and its surrounding areas. Previously, the same meteorite was observed by residents of other regions Russian Federation, but they were much luckier than the residents of Chelyabinsk, because it simply flew past them without causing absolutely any harm. For example, at 7.15 Moscow time or at 9.15 local time it was seen by residents of the Aktobe and Kostanay regions of Kazakhstan, and residents of Orenburg observed this amazing phenomenon at 7.21 Moscow time. This meteorite was also clearly visible in Sverdlovsk, Kurgan, Tyumen and their environs, and even 750 km from the crash site in the village of Prosvet, Volzhsky district, Samara region.
Bright flash
According to the US National Aeronautics and Space Administration (NASA), a meteorite weighing about 10 tons and with a diameter of approximately 17 meters, with a speed of 17 km/s, entered the Earth's atmosphere and after 32 seconds split into many parts. The destruction of the meteorite was accompanied by a series of explosions, the first of three explosions was the most powerful and caused the destruction. It was a bright flash, it lasted about five seconds, and a minute later it came to Earth in the form of a destructive wave. According to scientists, the destruction of the meteorite led to the release of energy, which was approximately equal to 100 to 500 kilotons of TNT equivalent. The center of the explosion was not the city of Chelyabinsk itself, but its region, which is located slightly to the south and is called Yemanzhelinsk - Yuzhnouralsk.
Places where fragments fell
As a result of research carried out by a specially created group, four places were discovered where meteorite fragments were supposed to be located. The first two places are located in the Chebarkul district of the Chelyabinsk region, the third in the Zlatoust district, and the fourth in the area of Lake Chebarkul. The information that the meteorite was located in the lake was confirmed by fishermen who were at the crash site. From their stories, members of the search group learned that at the moment the meteorite fell into the lake, a column of water and ice about 3-4 meters high rose from it.
