How dangerous is the threat from outer space, what to do with the found meteorite? What is the largest meteorite that fell to earth
Astrophysicists from Canada claim that the mass of the meteorite stream bombarding our long-suffering planet exceeds 21 tons per year. But in most cases, this goes unnoticed, since a person can observe and find meteorites only in the habitable zone.
The share of land on the Earth's surface is only 29%, the rest of the planet is occupied by the oceans. But even from these 29%, it is necessary to take away places that are not inhabited by humans or are completely unsuitable for habitation. Therefore, finding a meteorite is a great success. However, there was a case when a meteorite itself found a person.
The case of a meteorite collision with a person
In the entire history of the fall of celestial bodies to Earth, only one officially documented case of direct contact of a meteorite with a person is known.
It happened in the USA on November 30, 1954. A four-kilogram meteorite, breaking through the roof of the house, injured the owner's leg. This means that there is still a risk that a more serious guest from outer space may fall on people's heads. I wonder what is the largest meteorite that fell on our planet?
Meteorites are divided into three categories: stony, stony-iron and iron. And each of these categories has its giants.
The largest stone meteorite
Relatively recently, on March 8, 1976, the cosmos presented the Chinese with a gift in the form of stones falling to the surface of the earth for 37 minutes. One of the fallen copies had a weight of 1.77 tons. It was the largest meteorite that fell to earth, having the structure of a stone. The incident occurred near the Chinese province of Jilin. The same name was given to the space guest.
Until now, the Jilin meteorite remains the largest stone meteorite discovered on earth.
The largest iron meteorite
The largest representative of the category of iron-stony meteorites weighed 1.5 tons. Found it in 1805 in Germany.
A colleague of the German meteorite, found in Australia, weighed only 100 kg less than the German one.
But everyone was surpassed by an iron guest from outer space, whose weight was ten times greater than all previously found meteorites.
The largest iron meteorite
In 1920, an iron meteorite with a diameter of 2.7 meters and weighing over 66 tons was discovered in the southwest of Namibia! Larger than this specimen on our planet has not yet been found. It turned out to be the largest meteorite that fell to Earth. The name was given to him in honor of the Goba West farm, whose owner stumbled upon him while cultivating the field. The approximate age of the iron block is 80 thousand years.
Today it is the largest solid block of natural iron.
In 1955, the largest meteorite that fell to earth, Goba, was declared a national monument and taken under state protection. This was a forced measure, since in 35 years, while the meteorite was in the public domain, it lost 6 tons in mass. Part of the weight was lost as a result of natural processes - erosion. But the main contribution to the process of "weight loss" was made by numerous tourists. Now you can approach the celestial body only under supervision and for a fee.
The meteorites discussed above are, of course, the largest of their kind ever discovered. But the question of which is the largest meteorite fell to earth remained open.
The meteorite that killed the dinosaurs
Everyone knows the sad story of the extinction of the dinosaurs. Scientists still argue about the cause of their death, but the version that the meteorite became the culprit of the tragedy remains the main one.
According to scientists, 65 million years ago, the Earth was hit by a huge meteorite that caused a catastrophe on a planetary scale. The meteorite fell on the territory that now belongs to Mexico - the Yucatan Peninsula, near the village of Chicxulub. Evidence of this fall was found in 1970 impact crater. But since the depression was filled with sedimentary rocks, they did not carefully examine the meteorite. And only 20 years later, scientists returned to its study.
As a result of the work carried out, it turned out that the funnel left by the meteorite has a diameter of 180 km. The diameter of the meteorite itself was about 10 km. The impact energy during the fall was 100,000 Gt in (this is comparable to the simultaneous explosion of 2,000,000 of the largest thermonuclear charges).
It is assumed that as a result of a meteorite impact, a tsunami was formed, the wave height varied from 50 to 100 meters. Dust particles raised during the impact tightly closed the Earth from the Sun for several years, which led to a sharp change in climate. and intermittent large-scale fires exacerbated the situation. An analogue of nuclear winter has come on the planet. As a result of the disaster, 75% of animal and plant species died out.
Nevertheless, officially the Chicxulub meteorite is the largest meteorite that fell to earth 65 million years ago. He practically destroyed all life on the planet. But in history, in terms of its size, it occupies only the third place.
First among the giants
Presumably 2 billion years ago, a meteorite fell to the Earth, which left a trace with a diameter of 300 km on its surface. The meteorite itself supposedly had a diameter of more than 15 km.
The crater left after the fall is located in South Africa, in the Free State province, and is called Vredefort. This is the largest impact crater, and left him the largest meteorite that fell to Earth in the entire history of our planet. In 2005, the Vredefort crater was listed as a UNESCO World Heritage Site. The largest meteorite that fell to Earth did not leave a photo as a memory of itself, but a huge scar in the form of a crater on the surface of our planet will not allow us to forget about it.
It has been noticed that the fall of meteorites, the size of which is measured at least tens of meters, occurs at intervals of hundreds of years. And larger meteorites fall even less frequently.
According to scientists, in 2029 a new guest wants to visit the Earth.
A meteorite named Apophis
The meteorite that threatens our planet was named Apophis (that was the name of the serpent god, who was the antipode of the sun god Ra in Ancient Egypt). Whether it will fall to the Earth or still miss and pass next to the planet is not known for certain. But what happens if a collision does occur?
The scenario of the collision of Apophis with the Earth
So, it is known that the diameter of Apophis is only 320 meters. When it falls to Earth, an explosion will occur, equal in its power to 15,000 bombs dropped on Hiroshima.
If Apophis hits the mainland, an impact crater will appear, having a depth of 400-500 meters and a diameter of up to 5 km. The resulting will destroy capital buildings at a distance of 50 km from the epicenter. Buildings that do not have the strength of a brick house will be destroyed at a distance of 100-150 km. A column of dust will rise to a height of several kilometers and then cover the entire planet.
The media stories about nuclear winter and the end of the world are overblown. The dimensions of the meteorite are too small for such consequences. It is possible to lower the temperature by 1-2 degrees, but after six months it will return to normal. That is, the predicted catastrophe, if it does happen, will be far from global.
If Apophis falls into the ocean, which is more likely, there will be a tsunami that will cover coastal areas. The height of the wave in this case will depend on the distance between the coast and the place where the meteorite fell. The initial wave can have a height of up to 500 meters, but if the fall of Apophis occurs in the center of the ocean, then the wave that reaches the coast will not exceed 10-20 meters. Although this is also quite serious. The storm will continue for several hours. All these events should be considered only as possible with some degree of probability. So will Apophis collide with our planet or not?
The probability of Apophis falling to Earth
Apophis will theoretically threaten our planet twice. The first time - in 2029, and then - in 2036. After conducting observations using radar installations, a group of scientists completely ruled out the possibility of a meteorite collision with the earth. As for the year 2036, today the chance of a meteorite colliding with the Earth is 1:250,000. And every year, as the accuracy of calculations increases, the probability of a collision decreases.
But even with such a probability, various options for the forced deviation of Apophis from the course are being considered. Thus, Apophis is an object of interest rather than a threat.
In conclusion, I would like to note that meteorites are strongly destroyed when they enter the earth's atmosphere. When approaching the Earth, the speed of the fall of guests from space is 10-70 km / s, and when it comes into contact with the gaseous atmosphere, which has a rather high density, the temperature of the meteorite rises to a critical one, and it simply burns out or is very much destroyed. Thus, the atmosphere of our planet is the best protector against uninvited guests.
We have been prophesied many times the End of the World according to the scenario that a meteorite, an asteroid will fall on Earth and smash everything to smithereens. But he did not fall, although small meteorites fell.
Can such a meteorite still fall to Earth, which will destroy all life? What asteroids have already fallen to Earth and what consequences did this entail? Today we'll talk about this.
By the way, the next End of the World is predicted for us in October 2017!!
Let's first understand what a meteorite, meteoroid, asteroid, comet is, with what speed they can hit the Earth, for what reason the trajectory of their fall is directed to the Earth's surface, what destructive force meteorites carry, given the object's speed and mass.
meteoroid
A meteoroid is a celestial body intermediate in size between cosmic dust and an asteroid.
A meteoroid that has entered the Earth's atmosphere with great speed (11-72 km/s) heats up due to friction and burns out, turning into a luminous meteor (which can be seen as a "shooting star") or a fireball. The visible trace of a meteoroid that entered the Earth's atmosphere is called a meteor, and a meteoroid that fell to the Earth's surface is called a meteorite.
Cosmic dust- small celestial bodies that burn up in the atmosphere, having an initially small size.
Asteroid
“An asteroid (a synonym common until 2006 - a minor planet) is a relatively small celestial body in the solar system moving in orbit around the sun. Asteroids are significantly inferior in mass and size to the planets, have an irregular shape and have no atmosphere, although they may have satellites.”
Comet
“Comets are like asteroids, but they are not boulders, but frozen flying swamps. They mostly live on the edge of the solar system, forming the so-called Oort cloud, but some fly to the Sun. When they approach the Sun, they begin to melt and evaporate, forming a beautiful tail glowing in the sun's rays. Superstitious people are considered harbingers of misfortune.
fireball— a bright meteor.
Meteor — “(Ancient Greek μετέωρος, “heavenly”), “shooting star” is a phenomenon that occurs when small meteor bodies (for example, fragments of comets or asteroids) burn in the Earth’s atmosphere.”
And finally, the meteorite:A meteorite is a body of cosmic origin that has fallen onto the surface of a large celestial object.
Most of the found meteorites have a mass from several grams to several kilograms (the largest of the found meteorites is Goba, whose mass, according to estimates, was about 60 tons). It is believed that 5-6 tons of meteorites fall on Earth per day, or 2 thousand tons per year.
All relatively large celestial bodies that enter the Earth's atmosphere burn up before reaching the surface, and those that do reach the surface are called meteorites.
And now think about the numbers: “5-6 tons of meteorites fall on Earth per day, or 2 thousand tons per year”!!! Imagine, 5-6 tons, but we rarely hear reports that someone was killed by a meteorite, why?
Firstly, small meteorites fall, such that we don’t even notice, a lot falls on uninhabited lands, and secondly: deaths from meteorite impact are not excluded, type in the search engine, in addition, meteorites repeatedly fell near people, on dwellings (Tunguska fireball, Chelyabinsk meteorite, meteorite fall on people in India).
More than 4 billion space bodies fall to Earth every day. this is the name of everything that is larger than cosmic dust and smaller than an asteroid, - this is what sources of information about the life of the Cosmos say. Basically, these are small stones that burn out in the layers of the atmosphere before reaching the earth's surface, a few pass this line, they are called meteorites, whose total weight per day is several tons. Meteorites that still hit the Earth are called meteorites.
A meteorite falls to the Earth at a speed of 11 to 72 km per second, in the process of tremendous speed, the celestial body is heated and glows, which causes a “blowing” of a part of the meteorite, a decrease in its mass, sometimes dissolution, especially at a speed of about 25 km per second or more . When approaching the surface of the planet, the surviving celestial bodies slow down their trajectory, falling vertically, while as a rule they cool down, so there are no hot asteroids. If a meteorite splits along the “road”, a so-called meteor shower can occur, when many small particles fall to the ground.
At a low speed of the meteorite, for example, several hundred meters per second, the meteorite is able to retain its previous mass. Meteorites are stone (chondrites (carbonaceous chondrites, ordinary chondrites, enstatite chondrites)
achondrites), iron (siderites) and stony-iron (pallasite, mesosiderite).
“The most common are stone meteorites (92.8% of falls).
The vast majority of stony meteorites (92.3% of stony meteorites, 85.7% of the total number of falls) are chondrites. They are called chondrites because they contain chondrules - spherical or elliptical formations of predominantly silicate composition.
Pictured are chondrites
Basically, meteorites are about 1 mm, maybe a little more .. In general, less than a bullet ... Perhaps there are a lot of them under our feet, perhaps they fell right in front of our eyes once, but we did not notice this.
So, what happens if a large meteorite that does not crumble into stone rain and does not dissolve in the layers of the atmosphere falls on Earth?
How often does this happen and what are the consequences of this?
Fallen meteorites were found by finds or by falls.
For example, according to official statistics, the following number of meteorite falls was recorded:
in 1950-59 - 61, on average per year 6.1 meteorite fall,
in 1960-69 - 66, on average per year 6.6,
in 1970-79 - 61, on average per year 6.1,
in 1980-89 - 57, on average per year 5.7,
in 1990-99 - 60, on average per year 6.0,
in 2000-09 - 72, on average per year 7.2,
in 2010-16 - 48, on average per year 6.8.
As we can see even according to official data, the number of meteorite falls has been increasing in recent years, decades. But, of course, we do not mean 1mm-three celestial bodies ...
Meteorites weighing from several grams to several kilograms fell to Earth in uncountable numbers. But there were not so many meteorites weighing more than a ton:
The Sikhote-Alin meteorite weighing 23 tons fell to the ground on February 12, 1947 in Russia, in the Primorsky Territory (classification - Zhelezny, IIAB),
Jilin - a meteorite weighing 4 tons fell to the ground on March 8, 1976 in China, in the province of Jilin (classification - H5 No. 59, chondrite),
Allende - a meteorite weighing 2 tons fell to the ground on February 8, 1969 in Mexico, the state of Chihuahua (CV3 classification, chondrite),
Kunya-Urgench - a meteorite weighing 1.1 tons fell to the ground on June 20, 1998 in Turkmenistan, in a city in the North-East of Turkmenistan - Tashauz (classification - chondrite, H5 No. 83),
Norton County - a meteorite weighing 1.1 tons fell to the ground on February 18, 1948 in the USA, Kansas (Aubrit classification),
Chelyabinsk - a meteorite weighing 1 ton fell to the ground on February 15, 2013 in Russia, in the Chelyabinsk region (chondrite classification, LL5 No. 102†).
Of course, the Chelyabinsk meteorite is the closest and most understandable to us. What happened when the meteorite fell? A series of shock waves during the destruction of a meteorite over the Chelyabinsk region and Kazakhstan, the largest of the fragments weighing about 654 kg was raised from the bottom of Lake Chebarkul in October 2016.
On February 15, 2013, at about 9:20 a.m., fragments of a small asteroid collided with the earth's surface, which collapsed as a result of deceleration in the Earth's atmosphere, the weight of the largest fragment was 654 kg, it fell into Lake Chebarkul. The superbolide collapsed in the vicinity of Chelyabinsk at an altitude of 15-25 km, a bright glow from the burning of an asteroid in the atmosphere was noticed by many residents of the city, someone even decided that this plane had crashed or a bomb had fallen, this was also the main version of the media in the first hours. The largest meteorite known after the Tunguska meteorite. The amount of released energy, according to the calculation of specialists, ranged from 100 to 44o kilotons in TNT equivalent.
According to official figures, 1,613 people were injured, mainly from broken glass from houses affected by the explosion, about 100 people were hospitalized, two were in intensive care, the total amount of damage caused to buildings was about 1 billion rubles.
The Chelyabinsk meteoroid, according to NASA's preliminary estimate, was 15 meters in size, weighing 7000 tons - these are its data before entering the Earth's atmosphere.
Important factors for assessing the potential danger of meteorites for the earth are the speed with which they approach the earth, their mass, and composition. On the one hand, the speed can destroy the asteroid to small fragments even before the earth's atmosphere, on the other hand, it can give a powerful blow if the meteorite still reaches the earth. If the asteroid flies with less force, the probability of preserving its mass is greater, but the force of its impact will not be so terrible. It is the combination of factors that is dangerous: the conservation of mass at the highest speed of the meteorite.
For example, a meteorite hitting the ground weighing more than a hundred tons at the speed of light can bring irreparable damage.
Information from the documentary.
If a round diamond ball with a diameter of 30 meters is launched towards the Earth at a speed of 3 thousand km per second, then the air will begin to participate in nuclear fusion and, under the heating of the plasma, this process can destroy the diamond sphere even before it reaches the Earth's surface: information from scientific films, on the projects of scientists. However, the chances that the diamond ball, albeit in a broken form, will reach the Earth are high, during the impact, a thousand times more energy will be released than from the most powerful nuclear weapon, and after that the area in the area of impact will be empty, the crater will be large, but the Earth has seen more. This is at 0.01 of the speed of light.
And what happens if you accelerate the sphere to 0.99% of the speed of light? Super-atomic energy will begin to act, the diamond ball will become just a cluster of carbon atoms, the sphere will flatten into a pancake, each atom in the ball will carry 70 billion volts of energy, it passes through the air, air molecules pierce through the center of the ball, then get stuck inside, it expands and reaches the Earth with a greater content of matter than at the beginning of the path, when it crashes into the surface, it will pierce the Earth at random and in breadth, creating a cone-shaped road through the root rock. The energy of the collision will break a hole in the earth's crust and blast a crater so large that you can see the molten mantle through it, this impact is comparable to the 50 impacts of the Chicxulub asteroid that killed the dinosaurs in the era BC. It is quite possible the end of all life on Earth, at least the extinction of all people.
And what will happen if we add more speed to our diamond sphere? Up to 0.9999999% of the speed of light? Now each carbon molecule carries 25 trillion volts of energy (!!!), which is comparable to the particles inside the Large Hadron Collider, all this will hit our planet with approximately the kinetic energy of the moon moving in orbit, this is enough to punch a huge hole in the mantle and shake the earth's surface of the planet so that it simply melts, this with a probability of 99.99% will put an end to all life on Earth.
Add another speed to the diamond ball to 0.99999999999999999999951% of the speed of light, this is the highest speed of a mass-bearing object ever recorded by man. Particle "Oh, my God!".
“Oh-My-God particle (“Oh my God!”) - a cosmic shower caused by ultra-high energy cosmic rays, detected on the evening of October 15, 1991 at the Dugway Test Site (English) in Utah using the Fly's Eye cosmic ray detector » (English) owned by the University of Utah. The energy of the particle that caused the shower was estimated at 3 × 1020 eV (3 × 108 TeV), about 20 million times greater than the energy of particles in the radiation of extragalactic objects, in other words, the atomic nucleus had a kinetic energy equivalent to 48 joules.
This energy has a 142-gram baseball moving at a speed of 93.6 kilometers per hour.
The Oh-My-God particle had such a high kinetic energy that it traveled through space at about 99.99999999999999999999951% of the speed of light."
This proton from Space, which “flared up” the atmosphere over Utah in 1991 and it moved almost at the speed of light, the cascade of particles that were formed from its movement could not even be reproduced by the LHC (collider), such phenomena are detected several times a year and no one does not understand what it is. It seems to be coming from a galactic explosion, but what happened to cause these particles to come to Earth in such a hurry and why they didn't slow down remains a mystery.
And if the diamond ball moves at the speed of the “Oh my God!” particle, then nothing will help and no computer technology will simulate the development of events in advance, this plot is a godsend for dreamers and blockbuster creators.
But roughly the picture will be like this: a diamond ball rushes through the atmosphere without noticing it and disappears into the earth's crust, a cloud of expanding plasma with radiation diverges from the entry point, while energy pulsates outward through the body of the planet, as a result, the planet becomes hot, begins to glow, the Earth will be knocked out into another orbit Naturally, all living things will die.
Taking into account the picture of the fall of the Chelyabinsk meteorite, which we recently observed, the scenarios of the fall of meteorites (diamond balls) from the film presented in the article, the plots of science fiction films - we can assume that:
- the fall of a meteorite, despite all the assurances of scientists that it is realistic to predict the fall of a large celestial body to Earth in decades, given the achievements in the field of astronautics, cosmonautics, astronomy - in some cases it is impossible to predict !! And the proof of this is the Chelyabinsk meteorite, which no one predicted. And the proof of this is the particle “Oh, my God!” with their protons over Utah in 91…. As the saying goes, we don't know what hour and day the end will come. However, for several millennia, humanity has been living and living ...
- first of all, we should expect medium-sized meteorites, while the destruction will be similar to the fall of the Chelyabinsk one: windows will burst, buildings will be destroyed, perhaps part of the area will be burned out ...
Terrible consequences, as with the alleged death of dinosaurs, are hardly to be expected, but cannot be ruled out.
- it is unrealistic to protect yourself from the forces of the Cosmos, unfortunately, meteorites make it clear to us that we are only small people on a small planet in the vast Universe, therefore it is impossible to predict the outcome, the time of contact of the asteroid with the earth is impossible, breaking through the atmosphere every year more and more actively, the Cosmos seems to be claiming to our territory. Get ready, don’t get ready, and if the forces of heaven send an asteroid to our Earth, you can’t hide in any corner .... So meteorites are also sources of deep philosophy, rethinking of life.
And here is another news! We just recently prophesied another end of the world!!! October 12, 2017, that is, we have very little time left. Presumably. A giant asteroid is heading towards Earth! This information looms in all the news, but we are so accustomed to such cries that we do not react ... what if ....
In the Earth, according to the versions of scientists, there are already holes and cracks, it is burning at the seams ... If an asteroid reaches it, and a huge one, as predicted, it simply cannot stand it. You can only save yourself by being in the bunker.
Wait and see.
There are opinions of psychologists that such intimidation is an attempt in any way to instill fear in humanity and control it in this way. The asteroid is indeed planning to pass the Earth soon, but it will go very far, one in a million chance that it will hit the Earth.
Who would not want to have at their disposal a real meteorite that came from the depths of space. After all, if you think about it, in fact, it is no less valuable than the lunar soil brought by both automatic stations and astronauts. Although, the meteorite may be even more interesting and valuable. It is possible that a piece of the surface of Mars, the remnant of the hypothetical planet Phaeton, or in general, a particle of deep space material from which our solar system is created, will fall into the hands of a meteorite seeker.
It's no secret that meteorites are not only a valuable material for scientific research, but also have a serious market value. Already far from enthusiasts, but professional diggers go in search of meteorites to all corners of the world. Often such groups are armed with the latest technology. Here are metal detectors, computers, a field laboratory, and other know-how to identify a space alien. Such groups rarely go out for good luck. The search is preceded by a scrupulous collection of information, both available information about the fall of large celestial bodies, and information gleaned from chronicles, the Internet, news channels, even social networks, where someone shared information about the flight of a bright fireball. And the meteorite hunters are already here.
Note that a gram of a meteorite costs from $1 on the black market. So far from always hunters are driven by a thirst for knowledge and a desire to touch the cosmos. Most often, everything rests on the banal cost of a meteorite. Such a find, weighing ten kilograms, will easily cost on the black market as a good foreign car.
But is it worth it to try your luck for a simple layman, a lover of astronomy, a person who just wants to experience awe from a grain of sand that was destined to travel in outer space for billions of years?
"Sands" of the Universe.
Oddly enough, finding a meteorite is not as difficult as it might seem at first glance. But we are talking about very small fragments, just grains of sand. The discovery of a large meteorite, which is of serious both scientific and material value, is still a great success. But beginners are lucky. It is worth noting that approximately 2-3% of the dust in your apartment is occupied by nothing more than a meteorite substance. Every day, from 30 to 150 -200 tons of meteorite material falls on our planet. But all this is distributed over the surface of our planet. In overwhelming quantities, tons of microscopic meteorites and meteorite dust burst into the atmosphere every second. Basically, they all burn in the upper atmosphere. By the way, meteorite dust became well known at the dawn of astronautics. At the first orbital stations, it was already noticed then that from the constant bombardment of windows with microscopic dust particles, they eventually become dull. Larger meteorites burn up at an altitude of 60-40 km above the ground. Flashing like a bright star for a fraction of a second, they scatter into thousands of microscopic fragments that fall like dust on our planet. But more or less large stones, the size of a tennis ball or more, often do not have time to burn out completely, and, having drawn a bolide across the sky, fall like a meteorite onto the planet. It all depends on the angle at which the celestial body entered the atmosphere, what was its speed relative to the Earth, what was the mass and composition. All this affects what can reach the surface, small fragments or an impressive stone. On average, every year 25,000 meteorites, with a total mass of 21 tons, reach the Earth's surface. It is clear that meteorites fall almost everywhere and always. And, therefore, you can find a meteorite anywhere. Even at home in the garden. First of all, you need to know well what a meteorite looks like, and how to distinguish it from ordinary stones and pieces of iron.
Let's give you the first piece of advice. It is not worth going into the field on the very first day and collecting all the stones and pieces of iron in a row. It is unlikely that with this approach it will be possible to find at least something. If you decide to become a meteorite finder, you should always have a magnifying glass and a good magnet in your pocket. Let's start looking for the simplest and most win-win. First of all, we arm ourselves with a whisk, a brush and occupy the roof where you are allowed to climb. It can be the roof of both a high-rise building and the roof of an ordinary village house. The garage roof is especially valuable if it is flat. Also a great place to search will be the area where water flows from the roofs and snow falls in the spring. This is where you should start looking for micrometeorites.
Working with a brush or a whisk, we collect everything that we find on the roof. We especially carefully inspect the slots of slate, roofing material fastening strips, all kinds of damage and cavities where a meteorite can get stuck. It is far from such a rarity when meteorites weighing several grams get stuck in the roof of houses and can lie there for a single year. We carefully sweep everything into a container. Together with dust and grains of sand, old foliage, moss, twigs and twigs will fall. Now we fill the collected garbage with water and everything that is of organic origin, like branches, foliage, fine dust, simply floats up. After stirring well, drain the cloudy liquid, after allowing it to stand for about 60-80 seconds. Now let's dry what's left at the bottom. This sand mixed with small pebbles is of interest to us. We begin to search among all this for that grain of sand that has made its way for billions of years in space. We take out a magnifying glass with a magnet. Iron meteorites are the most common. Everything that sticks to the magnet is carefully examined.
Needless to say, we immediately throw away nails, small chips, which, it is not known how, got on the roof. Everything that has a man-made origin is not difficult to recognize. But all that has an irregular shape, we are most interested. Small pebbles that are magnetized and have a brown or black color are the most interesting to us. Most of the sand stuck to the magnet will be of meteorite origin, unless your house is near a metallurgical plant or a machine-building plant. We do the same with the ground under the roof of the house, the drain. Having also walked through the forest, the field, when the grass is mowed, or when the snow has just melted, we select suspicious stones that meet the signs described in the article. If, when viewed through a magnifying glass, the places of melting are visible, or if the needle managed to scratch the dark layer and metal flashed under it, then we can safely assume that you have a tiny heavenly wanderer in your hands.
Almost all meteorites contain iron. The type to which the meteorite belongs depends on its quantity. More information about meteorites can be found on the Internet. We’ll talk about how to recognize a meteorite in general and not confuse it with completely terrestrial material.
Meteorites are divided into three main groups. Iron meteorites are, in fact, a monolithic piece of iron. Such a meteorite can consist of both pure iron and include nickel, less often other metals. Iron-stone meteorites are a type of metal sponge interspersed with minerals, such as olivine.
Stone meteorites are the rarest and more difficult to distinguish from ordinary terrestrial stones. On the chip, they are interspersed in the form of silicate balls (chondrules) and metal particles. By the way, if you find the same silicate balls in the sand from the roof, then you can safely say that they are of purely cosmic origin.
Pure stone meteorites are rare. But even they have metal in them. Therefore, the meteorite deflects the compass needle and is attracted by the magnet. Naturally, the more it is on the surface of the earth and in contact with water, the more iron oxide will be on it. By the way, it is the humid climate that is the main killer of meteorites. Oxidation leads to the destruction of the meteorite.
Further, regmaglipts will be observed near the meteorite. These are pits and cavities that are formed during exposure to high temperatures as it flies through the atmosphere. But often a meteorite can be smooth and not have such depressions and pits. This happens when a meteorite explodes at a high altitude, and its small parts fly in different directions like shrapnel. If the fragments rotate, then they will have an irregular shape, dotted with regmaglipts. But those that did not have rotation are not uncommon in the form of a bullet, a cone, they can look like a piece of the tip of a fang. At the end of such meteorites, traces of a slush will be noticeable, which was blown away during the passage of the atmosphere back. On the conical part, the meteorite will have a melting crust only a micron or a few microns thick. But at the end up to a millimeter. It must be remembered that a meteorite can never burn out completely and have a porous structure.
If you come across something like this, it is most likely slag, which has a completely terrestrial origin or foundry waste. Also, a meteorite cannot contain easily crumbling substances, like chalk, feldspar or gypsum, in its composition. Therefore, if you still collected material in the field, on the road, under the roof of structures, where everything was washed off the roof with snow and water, where there may be larger suspicious objects, if you scrape you will see that it easily collapses and crumbles, most likely it is not a meteorite.
If you are lucky, and you have a decent suspicious object in your hands, which is well magnetized, deflects the compass needle, has a melting bark, it is worth trying to polish one part of it. If dimensions allow, then simply rub it on fine sandpaper, or, holding it in a vise, work with a file. Then, try to polish the saw cut. Having etched a polished saw cut with nitric acid (or a saw cut if the meteorite is quite large), the Widmanstatt structure will immediately become visible.
Another important detail. A meteorite always has a greater density than any rock. He's heavy. Even if you take the same volume of granite and meteorite, the latter will be noticeably heavier. If a combination of signs is enough, you can safely say that you have a space guest in your hands.
Most often, meteorites are confused with metallurgy waste - slag. They have a melt, heavy in weight, shiny inclusions of metal. But at the same time they have a porous structure. A meteorite is never porous. Igneous rocks and magnetites are also often mistaken for meteorite. Their weak magnetization is confusing. But on the chip, quartz crystals will be visible, which will even form veins. This does not happen in meteorites. And the magnetic properties of such rocks are given by the presence of magnetite, hematite, ilmenite, etc. in them.
The knowledge described above is quite enough not to carry all the stones home. Also, all of the above will allow the reader not to pass by some, at first glance, a cobblestone lying on the road, dug out in a garden, or a stone lying on fresh arable land, which may turn out to be a serious specimen of a meteorite that flew to us from the depths of space. Therefore, here is the last piece of advice for you - it is better to give any large finds, in whole or in part, to the museum. Scientists will "talk" them there. Even if you can sell your stone, won't your conscience torment you that perhaps because of your greed, some secret of the Universe has remained unsolved?
Chelyabinsk meteorite - why was it not tracked, can we expect new ones to fall and how strong is the meteorite threat? Astronomers speak.
All about meteorites
Alexander Bagrov, Doctor of Physical and Mathematical Sciences, Leading Researcher of the Space Astrometry Department of the Institute of Astronomy of the Russian Academy of Sciences (INASAN).
About meteorites
- To answer the question about the origin of meteorites, it is necessary to tell about the origin of the solar system. According to my research, it turns out that the solar system arose about 5 billion years ago. Moreover, the planets arose before the sun arose. The idea that is contained in the Six Days fell into my soul very much, that at first God created the Earth, grass already grew on it, and the Sun arose only on the third day of biblical creation.
We also believe that all the planets first arose, and then the Sun flared up and became a star. The most interesting thing is that the ignition of the Sun coincided with the situation when one of the planets that was between Mars and Jupiter exploded, its fragments scattered throughout the solar system, and now make up the so-called Asteroid belt. It is possible that the fall of these fragments onto the surface of the then still cold Sun caused the onset of nuclear reactions on the Sun, that is, it ignited this star.
Fragments from the Asteroid Belt can enter our atmosphere. If they do not burn up in the atmosphere, then they fall to the ground, and when we find them, we call them meteorites.
What happened in the sky over Chelyabinsk?
There was a fireball phenomenon over Chelyabinsk - one meteorite flew over the city. This is not a meteor shower, as some journalists say. A meteor shower is the fall of numerous meteorites. As the song says: “One snowflake is not yet snow, one rain is not yet rain,” so one meteorite is not yet a meteor shower.
A meteorite is what we found on earth, and cosmic bodies fly in space. Large bodies are called asteroids, small bodies are called meteoroids. If the body burned up in the atmosphere, then it is called a meteor, if it flew, then the substance found is called a meteorite.
In space, every body moves in its own orbit, and if it does not collide with anything, then it can fly in its orbit for billions of years. But it collides with various elements of the solar system, such as photons that fly from the Sun. Each collision leads to a small change in the orbit. If this change causes the body to meet a planet on its way, then it crashes into it. If this is our planet, then we are seeing starfall, shooting stars, meteors, or meteorites. Every day, dozens of meteors fly over our heads, and millions of meteors fly over the entire earth. The earth has existed for billions of years, and you can imagine how much everything flew in and burned up above the earth. If the cosmic body has sufficient mass, then it does not have time to burn out entirely and reaches the earth. So in 1947 the Sikhote-Alin meteorite fell to the ground. 70 tons of iron flew, and 27 tons were found on the ground.
Why is a meteorite hard to track?
Let me give an analogy - if we cross the road, then we looked to the left and right in search of dangerous bodies - cars. We do not follow the insects under our feet. It is the same here - we don’t even have in our thoughts to keep an eye on small celestial bodies, because they are not dangerous. Dangerous bodies are those whose diameter is above 140 m. The whole world is thinking about how to competently organize a service in order to monitor them. And the meteorite over Chelyabinsk is only a few meters in diameter. You will not see a bug at a distance of 10 km, and it flies these 10 km in a second. It is impossible to keep track of them, and it is useless.
In Russia and in the world, the monitoring system has not been established. The largest asteroids are tracked, but they fly far from the earth, in the region of the Asteroid Belt. Sometimes smaller asteroids fly up to us, but closer. The appearance of such a small asteroid is as sensational as the approach of asteroid 2012 DA14 is now.
Did meteorites harm people?
There was once a case when, I think in the 14th century, a meteorite killed a Chinese. History does not know when a meteorite killed someone other than this Chinese. Sometimes they caused damage. A few years ago, a meteorite hit the roof of an American woman's house. She got more money for it than the whole house was worth.
If the Tunguska meteorite in 1908 would have exploded not over the taiga?
The damage would be very significant. The power of its explosion is estimated at 50 megatons of TNT equivalent, trees in the taiga were knocked down over an area of several thousand square meters. kilometers. If the explosion had occurred over St. Petersburg, then there would be little left of the city.
Should we expect new meteorites?
– This is to be expected, because a lot of things fly in space. In order to keep track of all of them, the system has not yet been created. The threat they pose is high enough for us to think about it. Now the question of a tracking system is being raised and, moreover, the question of creating a countermeasure system is being raised. If such a dangerous body flies to the ground, then you need to get rid of it.
Are there developments in Russia of a system for counteracting meteorites?
Developments are underway, but only at the level of papers, words and ideas, because any equipment costs money, and the money we have in Russia goes to the oligarchs.
Yuri Pidoprygora, astronomer, PhD in physics and astronomy, researcher at the radio astronomical observatory in the village of Dwingeloo in the north of the Netherlands.
From the point of view of astronomy, the phenomenon is unremarkable, the fall of celestial bodies of this magnitude (it is still difficult to accurately estimate the size of a meteoroid or microasteroid, but it clearly does not exceed a couple of meters) occurs on average once every few months, well, maybe once a year.
Once upon a time, astronomy was taught in schools and there was such a topic, “Meteors and fireballs”. Young astronomers went on meteor patrols in the summer and everyone dreamed of seeing such a fireball as it flew over Chelyabinsk today. In textbooks and reference books there were diagrams on how to correctly mark the passage of such a celestial body and the address was attached where to send the report in case of luck ...
NASA estimates the size of the Chelyabinsk microasteroid at 15 meters. If this is true, then this event is more unique than previously thought - perhaps the most interesting since the famous explosion over Tunguska.
The only interesting thing here is that the trajectory ran over relatively densely populated areas. And, of course, a funny coincidence in time with the “close” (~ 30,000 km) flyby of the asteroid DA14, which has been much talked about in the press in recent days, which led to a bunch of “misunderstandings” (it would be nice to know how accidental or intentional ) when covering this event in the media.
Even the monitoring of truly dangerous large nearby asteroids is currently being carried out at a far from adequate level, to say nothing of small pebbles. There is another problem - near-Earth orbits are clogged with space debris, which, by and large, no one cares about either. So it’s still good if just a stone falls on your head, and not a barrel with a ton of highly toxic rocket fuel or a spent nuclear reactor ...
Tatyana Sinitsyna, columnist for RIA Novosti.
The recent fall of a meteorite in Peru (Dezagvadero department of Puno province) has already acquired a lot of assumptions and fantasies. According to eyewitnesses, the fireball crashed into the ground to a depth of 6 meters, leaving a 30-meter crater from which a fountain of boiling water escaped. But the main thing is that after a while people felt a strange smell, nausea and headache. A representative of the Peruvian Ministry of Health hastened to declare that "the malaise is caused by poisonous fumes from fragments of a cosmic body, fragments of which may be meteorites, in which there is a high content of organic substances, in particular, cyanide."
“Everything that is reported from Peru is typical of meteorite falls,” confirmed RIA Novosti the head of the laboratory of meteoritics at the Institute of Geochemistry and Analytical Chemistry. V.I.Vernadsky, Doctor of Geological and Mineralogical Sciences Mikhail Nazarov. - However, with regard to reports of "strange diseases", allegedly caused by the newly-minted "space guest", then there is doubt. Over the 250 years of the existence of meteoritics in Russia, 102 large meteorite falls have been recorded, 70 of them have been found, 50 samples are stored in the Meteorite Collection of the Russian Academy of Sciences. However, they did not have any negative impact on human health.”
No consequences were noted even after the unique “Sikhotealinsky rain” (February 12, 1947), when a whole stream of meteorites with a total mass of up to one hundred tons fell on the Far Eastern Ussuri taiga, in the region of the Sikhote Alin mountains, covering an area of 35 square meters. kilometers. There is also no information that any other meteorite that fell to the ground (a thousand of them were recorded) manifested itself from a “dangerous” side for human health. “Meteoritic matter, as far as scientists know it, is harmless and quite sterile, compared to terrestrial rocks,” says Mikhail Nazarov. - No microbes, bacteria or viruses of extraterrestrial origin have been found on meteorites. And if we talk about radioactivity, then it is much higher in terrestrial granite rocks.
What then could happen to the Peruvians? “A powerful shaking during the fall of a meteorite could cause cracks in the soil, a violation of the groundwater regime, as a result of which poor-quality waters rich in harmful gases, contaminated, etc. could form and enter the sphere of use (rivers, wells, etc.), - believes Mikhail Nazarov. According to him, the meteorite is unlikely to emit (reportedly) smells of lead or silver. These substances, if they are contained in meteorites, then in negligible quantities, their main component - iron sulfides. It was previously noted that after the fall, meteorites emit a certain sulfuric smell, but this will not poison the population. In the Peruvian case, it can be assumed that ore deposits turned out to be in the “target” zone, which reacted to the meteorite impact with the evaporation of their substance. But this is a local and, of course, temporary effect, the scientist is sure.
The Earth's atmosphere plays the role of a shield that protects the planet from falling invading cosmic bodies. Their minimum speed at the entrance to the atmosphere is 11 km/sec. As a result of deceleration, meteorites lose their energy of motion, evaporate, turning into cosmic dust, or fall in the form of meteorites (it all depends on the initial size). Their mass ranges from a few grams to tens of tons. Meteorites seem to be similar, but, nevertheless, different in composition and there are iron, stone and mixed (iron-stone). Some come from the asteroid belt, others are of planetary origin, for example, lunar and Martian meteorites are pieces of rocks from the Moon and Mars.
As Mikhail Nazarov said, there are approximately 20 types of meteorites. Small ones (Peruvian is also considered this) give only mechanical damage. However, with large impacts, there can be global environmental consequences. For example, 65 million years ago, in the Mesozoic era, the entire biota, including dinosaurs, was destroyed by the collision of the Earth with a large cosmic body (or group of bodies).
The fall of meteorites is the area of the elements. Scientists are trying to set up a service for observing asteroids, but the problem is that over time they change their orbits. The second problem is that it is almost impossible to change the trajectory of the fall of a meteorite so that it does not collide with the Earth.
According to Mikhail Nazarov, "the fall of the Peruvian meteorite is still not a very powerful event." The crater is small, 30 meters, and sometimes it reaches a huge size, calculated in many kilometers.
What will happen next? Scientists will extract fragments of the meteorite, examine them, give a conclusion on the geochemical composition, determine the weight, chemical composition, substantiation of the type, coordinates of the fall. Then the meteorite will be given a name (usually according to the place where the find fell). Thus, arriving on Earth, the space "aliens" receives a kind of passport, on the basis of which it is registered in the Meteoritic Society. Then everyone will know exactly what this “thing” is.
