Apocalyptic scenarios of asteroids falling on our planet for the vast majority of people are the result of the imagination of science fiction writers. However, common sense says that such an event, sooner or later, will happen.
And very soon, on October 12, 2017, asteroid 2012 TC4 will pass in a rather dangerous proximity to our planet. Despite the fact that the chances of a collision with the Earth are extremely small ( about 0.00055%), such a turn of events cannot be completely ruled out.
What is known about the 2012 asteroid TC4
July 27 and 31, and then 5th of August this year, experts from the European Space Research Agency observed an asteroid approaching Earth 2012 TC4. The observation was carried out through a complex of 8.2-meter telescopesEuropean southern observatories.
We are talking about the first observations of this small asteroid since its first discovery - that is,since October 4, 2012. At the time of the last observation, the asteroid 2012 TC4 was still very far from our planet, at a distance of about 56 million kilometers.
FROMIn 2012, this TS4 could not be observed from Earth. The fact is that the apparent stellar magnitude (that is, a measure of the brightness of a celestial body) of this asteroid was 26,4 , which is very, very small (for example, for the brightest celestial bodies, including the Sun, negative values this measure).
An object with a similar magnitude to 60 billion times dimmer than the planet Saturn as seen from Earth. The asteroid is approaching at a speed 14 kilometersper second getting brighter. At the closest approach to the Earth, the apparent magnitude of the asteroid 2012 TC4 will be only 13.
Recent observations of the asteroid made it possible to clarify information about its size ( from 12 to 27 meters in diameter) and location, and enabled scientists fromCenter research near-Earth objects(CNEOS) NASA(National Aeronautics and Space Administration) to calculate its future orbit and the distance at which it will fly past our planet at the moment of closest approach to it.
The obtained results of calculations indicate that the closest approachasteroid 2012 TC4 will happen to Earth October 12 this year: the space object will fly by at a distance equal to 43500 kilometers from our planet (this is about one eighth of the distance of the moon from the earth). There are also less optimistic forecasts, which, however, are not intended to cause panic: according to them, a space object will not approach the Earth closer than a distance of 6800 kilometers.
Where will the asteroid hit on October 12?
NASA scientists are looking forward to the upcoming asteroid flyby, planning to use the event as an opportunity. test the network of NASA observatories who are working on a planetary defense program. As part of the program for tracking potentially dangerous objects for our planet, further observations of the asteroid are planned both by NASA and other astronomers.
Michael Kelly(Michael Kelley) , Head of the TC4 Asteroid Observation Program at NASA Headquarters, stressed that scientists' efforts today are focused on studying this asteroid in order to test the operation of the worldwide asteroid tracking network. According to him, this will allow assessing the possibility of determining a potential real threat from such space objects, as well as assessing the ability to respond.
Is it possible to prevent the threat of collision in the future?
In order to prevent the threat of an asteroid colliding with our planet, it is necessary to detect the corresponding space object. for several years before the expected fall.
Objects diameter up to several hundred meters are unlikely to cause a global catastrophe, although they can cause significant damage when they enter infrastructure.
Another thing is asteroids with a diameter several kilometers: the fall of such an object to Earth with a high probability can lead to a global catastrophe with the subsequent mass extinction of all life.
At the moment, the activities of many planetary protection programs are reduced to the observation and identification of potentially dangerous space objects. Moreover, they began to catalog these objects back in 1947 when it was founded Minor Planet Center at the University of Cincinnati, USA.
To date, we can talk about a dozen programs that track near-Earth objects as part of a global project called "Space Security Watch" However, in reality, these programs are weakly related to each other.
It turns out that humanity today is absolutely defenseless against the threat of the fall of a large space object, which can threaten the death of all life? Alas, it is. However, a start has been made, future programs are being developed, telescopes are being built, high precision tracking systems.
And already now we can talk about the successful results of this work, which made it possible to predict the time and place of the fall of a space object before its entry into the Earth's atmosphere.
October 6, 2006 telescope "Catalina sky review", located in Arizona, USA, an asteroid approaching Earth was detected 2008 TS3. Thanks to the data obtained, the corresponding calculations were carried out, which made it possible to accurately determine the time and place of the asteroid's fall: a space object with a diameter of 4 meters fell through 19 hours after being discovered in the north of Sudan, in the Nubian desert. If the asteroid had chosen a large city as the site of impact, 19 hours could have been enough to evacuate residential areas at the alleged impact site.
Another question is what humanity is capable of countering the threat from the sky, provided early recognition? Now, in fact, nothing. However, intensive work is underway to develop potential options for repelling the threat, among which we can mention the detonation of a nuclear explosive device (the topic is disclosed in the blockbuster "Armageddon"), the so-called kinetic ram (a huge artificial object crashing into a small asteroid), an asteroid gravitational tug, focused solar energy, an electromagnetic catapult, and a number of other options.
Fallen asteroids
September 1This year, NASA specialists observed the approach of the largest space object in the history of observations - asteroid (3122) Florence. The fall of this object on the surface of our planet would hardly have left at least some chance for its inhabitants.
However, Florence passed at a distance of about 7 million kilometers from the earth. It is reported that today it is possible to observe asteroids with a diameter up to 10 meters. Why, then, did the approach of the famous Chelyabinsk meteorite, whose diameter was, according to various estimates, from 17 to 20 meters?
It is estimated that from the moment the Chelyabinsk meteorite entered the atmosphere until the moment of its destruction, 32.5 seconds. According to NASA experts, this object belongs to chondrites of asteroid origin(contains silicate elliptical or spherical formations, chondrules). This material poorly reflects light, so it was not spotted in space. In addition, it entered the atmosphere from the side illuminated by the Sun.
All these factors prevented the discovery of this object. Not a very optimistic statement, given the fact that chondrites make up over 90% from the number of all stone meteorites falling to the Earth.
Asteroids of the solar system
As the case with the Chelyabinsk meteorite showed, falling objects (similar to it in size, or smaller) can be expected in any moment in time. If we talk about large asteroids, then already in August 2032 an object with a diameter of over 400 meters.
In this case, the probability of a collision will be much higher than in the case of an asteroid. 2012 TS4 (about 0.002%). In total, in the relatively foreseeable future (within two hundred years), a about 20 potentially hazardous asteroids, the largest of which is up to 1200 kilometers.
In fact, every month astronomers discover dozens of asteroids, but not all of them pose a potential danger to our planet. The estimated probability of the Earth colliding with an asteroid comparable in size to the Chelyabinsk meteorite or asteroid 2012 TC4 allows us to conclude that such an event occurs once every 100 years.
Objects diameter up to 1 meter fall to the earth's surface every year. But asteroids several kilometers in diameter, like the one that allegedly destroyed the dinosaurs, visit our planet. once every 20-200 million years!
The danger to civilization can lurk both in the person himself and be external. Something tells me that for a better understanding of the world around us, the reader just needs to get acquainted with these external dangers. At least with some of them.
The first thing that can come to a person’s mind when they are told about the danger threatening our planet is this. Such is the influence of the media and Hollywood films. Much less is known about other dangers to the general public. Well, let's start with the well-known...
Journalists and Hollywood did not come up with anything new. Earth has repeatedly been subjected to devastating asteroid bombardment. And more than once it will be exposed, judging by how often it happened before.
To mention only a few cases, this will be enough to make an impression.
So, about two billion years ago, an asteroid fell on our planet, the size of which is comparable to the size of Mount Everest. After the impact, a crater with a diameter of 140 km appeared, which is located in South Africa. I don’t know if tourists are taken to this crater, but they are taken to the famous Arizona crater (America). This crater is 1,200 m in diameter and 175 m deep. It was left after a huge meteorite, consisting of nickel iron. The crater makes a strong impression, especially from the air. But compared to what fell on our planet before him, the Arizona meteorite is simply a sweetie.
One of the worst catastrophes in the history of the Earth occurred approximately 250 million years ago, at the end of the Permian period. The impact of an asteroid that fell somewhere between Australia and Antarctica was so powerful that it caused massive volcanic eruptions in the opposite region - in Siberia. As a result, more than 90% of vertebrate marine animals have disappeared from the face of the Earth. Life was practically wiped off the face of the planet, evolution had to start almost from the beginning.
Another, slightly smaller, catastrophe occurred about 65 million years ago. Then the dinosaurs were out of luck. An asteroid larger than 15 km in diameter fell in the Gulf of Mexico, not far from the Yucatan Peninsula, where a crater with a diameter of about 200 km remained as a memory of it. (By the way, some scientists believe that the Gulf of Mexico itself is nothing more than an asteroid impact crater. This round gulf is actually very suspicious in shape.)
A powerful seismic wave swept through the center of the planet, which played the role of a kind of "lens", and focused on Hindustan, located just opposite, which at that time was still an island. Through the cracks that appeared on the surface of our planet, billions of tons of molten basalt poured. Numerous new-found volcanoes threw into the atmosphere an unimaginable amount of ash that obscured the Sun. The lack of sunlight led to the cooling of the Earth and, as a result, the ice age began and the death of dinosaurs, which died out in a record time for evolution.
In addition to the cases described, there are craters whose age is estimated at 125, 161, 295, 330 and 360 million years ... Notice the periodicity. The last major meeting took place 65 million years ago. It's time to meet again. For a very long time there were no uninvited guests, each of whom is worse for us than all the Tatars put together ... and in general, the guests are “catching up”. In 1908, a comet exploded in Russia near Podkamennaya Tunguska. And the comet was so-so, and there was enough talk about it for a century. Because the comet showed on a micro scale what would happen to the Earth if it collided with a larger object ...
In principle, people were very lucky then - if they had fallen in a more populated place, the history of mankind could have gone in a completely different way. If this one had fallen only six hours later, it would no longer be called Tungussky, but Moscow. Naturally, Moscow would have been destroyed. A couple more hours of delay - and Berlin would have been wiped off the face of the planet. The fact is that the force of the explosion of the Tunguska meteorite was about 20 megatons! For comparison: a bomb with a capacity of only 15 kilotons was dropped on Hiroshima, and 20 kilotons on Nagasaki. A thousand times smaller than the explosion in Podkamennaya Tunguska!
Despite the fact that the Tunguska meteorite exploded at an altitude of 10 km, the age-old forest was dumped on an area of 2,150 hectares. The shock seismic wave doubled (!) circled the Earth. After the explosion, not only in Siberia, but also in Europe, there were white nights for several days and silvery clouds were observed - so much dust was in the atmosphere after this air explosion. Moreover, the diameter of this meteorite was only 50-60 meters.
1996, May - an asteroid with a diameter of 500 meters flew only 450,000 km from us, and six days later another asteroid with a diameter of 1.5 km approached our planet by 3 million kilometers. By space standards, this is very close. 1998 - asteroids whistled at the temple three times - in February, September and November. In 1999 - in March and June. There were two cases in 2000.
What happens if a large asteroid hits the Earth? The researchers calculated the catastrophe process on computers. In the fall of an asteroid that is only one kilometer across, everything within a radius of a thousand kilometers from the crash site will be destroyed. Fires will capture vast territories, a huge amount of ash and dust will be thrown into the atmosphere, which will settle for several years. The sun's rays will not be able to break through to the surface of the Earth, due to a sharp cold snap, many species of heat-loving plants and animals will die, and photosynthesis will stop. There will be what can be called a nuclear winter. Most people and animals will starve to death...
And when eventually the dust settles and atmospheric circulation is restored, there will be a greenhouse effect due to a significant increase in carbon dioxide in the atmosphere. The temperature in the surface layer will increase, which will lead to the melting of polar ice and flooding of the coastal part of the land. In addition, the magnetic field of our planet will be disturbed, the dynamics of tectonic processes will change, and the activity of volcanoes will increase.
When an asteroid falls into the ocean, the consequences of the impact will be no less terrible. Giant tsunamis will overwhelm the land, and almost immediately all living things will die on almost all coasts of the globe. Water dust entering the atmosphere will completely change its circulation, which will change the climate unpredictably.
Both options are disastrous for civilization. Let me remind you that we are talking about a body with a diameter of only a kilometer. The most unpleasant thing is that the chances of dying in such a disaster for the whole of humanity are no less than the chances of an individual person dying in a car accident. What does this mean? Every day we hear or read reports about that.
How many people died in an accident, it is naive to believe that this cup will blow us for sure. But if our planet were a member of some galactic community of about six billion members, every year we would receive information about hundreds of thousands (!) Of civilizations killed by asteroids. Hundreds a day.
The first to take this problem seriously was the US government. Since 1981, NASA has held regular meetings on the asteroid problem. Since 1991, these meetings have taken on an international character - at the initiative of NASA and the International Astronomical Union, a Working Group on the Study of Near-Earth Objects has been established. The Americans have developed a project called "Space Guard". It involves the placement of six 2.5-meter telescopes on the Earth's territory, which will carry out constant monitoring of space. With the help of this project, they hope to obtain accurate data on the movement of asteroids in outer space, calculate their trajectory, mass and speed. And maybe escape by hitting the asteroid with nuclear warheads...
The main supporters of the nuclear project are American nuclear scientists, under the leadership of E. Teller, the honorary director of the Livermore National Laboratory of the United States. They believe that it is high time to make an experimental explosion on one of the asteroids flying by in order to work out the technique of delivering and navigating charges, to assess the limits of our technological capabilities.
But not all scientists support this project. Many, in order to knock the asteroid off a dangerous course, offer to fire at it ... with lead ingots! The impact of a multi-ton lead ingot may well deflect the asteroid by a tenth of a degree from the deadly path, and with correct calculations, this will be quite enough.
Irradiation of the surface of a cosmic body with high-power lasers seems to be very promising. Firstly, the change in mass caused by the abrupt evaporation of matter will in itself lead to a change in the flight trajectory, and, secondly, the flow of hot gases should become a kind of jet engine for the asteroid.
After all, we can simply fly to an asteroid and build several space engines on its surface, turning the asteroid into one giant rocket. The launch of rocket launchers will knock the asteroid off course ... However, while this is all science fiction, it is a matter of the future, which we still have to live to see. But in the "asteroid" case, there is at least the prospect of solving the problem - to shell. And what do you want to do with supernovae? ..
Supernovae are known as exploding stars. Our yellow dwarf is not in danger of becoming a supernova in the foreseeable future, but nearby stars - more massive - can throw out a similar trick.
At the time of the explosion, a supernova radiates as much energy as the Sun can generate in 5 billion years, that is, the exploded star shines like five billion Suns! Do you think the stars are far away and it won't hit us? Alas, if such a "joyful" event occurs within a radius of 25 light years from the Earth, it will inevitably leave its "scar" on Earth. Streams of ultraviolet, x-ray and gamma radiation will reach our planet and damage its ozone layer.
Gaps will appear that won't last for decades. Hard solar ultraviolet during this time will kill plankton - the basis of the food chain in the oceans. The mass extinction of living creatures in the ocean will begin, and then on land. Under the influence of cosmic rays in the upper atmosphere, the content of nitrogen dioxide will increase sharply. The smallest droplets of this gas form a fog that will envelop the Earth and cool its atmosphere. Unpleasant...
Much worse if the star explodes even closer. It has already been calculated that with a supernova explosion at a distance of 10 light years from our planet, the amount of ozone in the earth's atmosphere will be reduced by a factor of three.
How big is this danger? In our Galaxy, supernova explosions are observed on average once every 50–100 years. That is, so far we have simply been lucky - most supernovae have exploded so far from the solar system that we have not even noticed them. In the immediate vicinity of us, that is, at a distance of several tens of light years, supernova explosions are observed approximately once every couple of hundred million years. The probability of this event is approximately the same as the probability of an asteroid falling on our planet with a diameter of ten kilometers.
And nevertheless similar with the Earth already was! Not only asteroids erased life on the planet almost to the ground, but also supernova explosions. In the mid-1990s, physicist John Ellis of the Swiss CERN and his American colleagues Brian Fields and David Schramm suggested that supernova explosions must leave a mark on rock deposits or layers of ice. The fact is that a real chemical factory begins to work in a hot gas shell, which the star has thrown off itself. In a matter of seconds, almost the entire assortment of the periodic table appears here, up to such a transuranium element as californium (serial number 98), which on Earth can only be obtained artificially.
If this chemical cloud ejected by a supernova covers our planet, then some exotic elements will penetrate into its atmosphere. Settling on the surface of the land or at the bottom of the sea, they form deposits as unusual as those left after the impact of a huge asteroid. (The meteorite that killed the dinosaurs was discovered because it left a huge amount of iridium in the layer that separated the Cretaceous and Tertiary periods.)
If, say, a star explodes 30 light years from us, then the total mass of matter that has fallen onto the planet will be about 10 million tons. (Which corresponds to a block with a diameter of only 200 m.) This mass is 10,000 times less than the mass of an asteroid that crashed into the Earth 65 million years ago and killed the dinosaurs. And if we consider that the substance of a supernova did not fall in one place, like an asteroid, but scattered throughout the planet, then it is very difficult to find it. However, some isotopes that are not found on Earth can give it away: for example, iron-60 and plutonium-244.
The long-awaited opening, as always, came unexpectedly. A group of German physicists led by Gunther Korschinek, while studying volcanoes, accidentally discovered iron-60 in sediments mined from the bottom of the Pacific Ocean near Pitcairn Island. In fact, scientists conducted other research. They collected samples of ferromanganese nodules in the southern part of the ocean. These layers, containing large amounts of iron and manganese, are often found in the vicinity of underwater volcanoes. It was here that an isotope of iron was discovered in an amount that exceeded the norm by a thousand times.
The half-life of iron - 60 is equal to one and a half million years. Scientists have calculated that this portion of the isotope entered the earth's atmosphere about five million years ago, and then settled on the ocean floor. The reason for the appearance of iron-60 could only be the explosion of a supernova, located 50-100 light years from the Sun. In those days, this star must have shone in the sky hundreds of times brighter than the full moon!
According to astronomers, since the origin of life on Earth (that is, over the past three billion years), supernovae have exploded several times in the vicinity of the solar system. It is possible to assume that these cosmic catastrophes significantly influenced the evolution of life on Earth. And not for the better.
But there are even more unpleasant things in the Universe than supernova explosions. Relatively recently, astronomers discovered an interesting phenomenon. How it was not noticed before is simply incomprehensible. It turned out that near-Earth satellites, observing the Universe in the X-ray range, every single day register a sharp flash of gamma radiation in some corner of the Universe. The flash lasts only a few seconds or even fractions of a second, but its power is huge: in a fraction of a second, as much energy splashes out as the Sun could radiate in ten billion years!
Scientists still cannot understand where such a monstrous energy comes from. Maybe these terrible universal lightning flashes when a neutron star disappears into the belly of a huge black hole or when they collide. As a rule, such flares are observed outside our galaxy. And what if "lightning" flashes within a radius of 3,500 light years from our planet?.. Employees of the Israeli Institute of Technology, located in Haifa, simulated such an event on a computer. It turned out that as many charged particles would rush to the Earth at once, how many reached it in the last 100,000 years. There will be the strongest radioactive contamination of air and soil! And its dose will be lethal to all living things. Within a month, half of the world's population will die out. The other half will die out a little later.
Perhaps the most massive death of animals on Earth - the "Perm catastrophe", which occurred about 250 million years ago - was caused by just such an outbreak. According to some reports, during the Perm disaster, 96% of the inhabitants of the planet became victims of a strange, unexpected pestilence. It was then that the famous trilobites disappeared from the face of the Earth. The cause of this tragedy remains unknown to this day.
Other dangers lie in wait for us. For the last several tens of millions of years, the Sun has been in a relatively quiet place - between two galactic arms. However, the solar system revolves around the center of the Milky Way (as our Galaxy is called, if anyone is interested) and after a certain time will enter the region of the galactic arm densely strewn with stars.
There we have to spend as much as 60 million years. Numerous stars will bring chaos to the gravitational order of the planets and comets of our system. Many comets from the so-called Oort cloud, hitherto “dormant” on the periphery of the solar system, will rush to its center, where they will inevitably collide with planets, including the Earth. Even worse, if the Earth itself changes its orbit, moving a little closer to the Sun or a little further away from it. It is unlikely that a person will be able to exist on a frozen or hot planet.
But, even if we manage to miraculously avoid all these dangers, anyway, after some time, we will have to get ready to say goodbye to the sun. It will become old, turn into a red giant and swallow the Earth. It won't happen right away. The sun will warm up gradually. The earth will also gradually be covered with deserts, which will lead to the mass extinction of animals. After half a billion years, the Earth will simply be scorched. And in another five billion years, the Sun will swell enormously. Its edge will almost reach our planet, and the Earth will be covered with a viscous, red-hot mess, reminiscent of volcanic lava.
“Of course, we will not sit back and wait quietly until the ruthless Universe will tear us to pieces! - the romantics of space travel will exclaim. - This is completely unacceptable! Firstly, you can fly somewhere with all your belongings. Secondly ... Secondly, fly away again. Even further. And then we'll see."
This is a good option, romance, but alas, even if we fly to another suitable star in our Galaxy, this will not be a cardinal solution to the problem. Much to my misfortune. The Milky Way at a speed of 500,000 km / s rushes towards the neighboring galaxy - the famous Andromeda Nebula. Every day, galaxies approach each other by ten million kilometers. Andromeda is now 2.2 million light-years away. Children's problem for the first class: after what time will the "trains" collide?
No, at first it will even be beautiful: when the “trains” approach, the sky will be dotted with such an incredible number of stars that at night people will be able to read a newspaper without turning on the lights. And a little later (in some four or five billion years) there will be no one to read the newspapers: the Milky Way will collide with the Andromeda nebula. I assure you it will be an unpleasant sight.
Maybe you're hoping that because the distances between individual stars are very large, the galaxies will pass through each other without noticing? Alas… The distances between stars are actually hundreds of millions of times greater than the diameter of the stars themselves. But there is no void between them, but there are huge masses of extremely rarefied interstellar gas. He is supposed to be the cause of the disaster. The gas clouds, invisible to us now due to their rarefaction, will heat up and flare up after the collision. In their midst, a thermonuclear reaction will begin. New stars are being formed. They will number in the thousands, or even hundreds of thousands. Their incandescent masses will emit a bright blue light. The gloomy cosmic distance will be illuminated by fireworks never seen before. It's just that there will be no one to look at him.
What are our chances? And can we count on anyone's help?
That's what I mean... Nature works with a margin. 99% of the entire primary matter of the Universe annihilated in the first moments. Of the thousands of biological mutations, one turns out to be successful and is fixed. Out of a thousand dandelion seeds, one or two will sprout. Many local civilizations on Earth could not withstand crises and perished. Now, in connection with globalization, we all have practically one Civilization with a capital letter. That is, now we are talking about life on the planet in general. If anything, now we will not get off with one outskirts, it will cover the entire world economy. Together with us. Maybe, out of dozens or hundreds of civilizations that are “sown” on different planets of the infinite space, only a few overcome global internal and external crises, that is, the survival rate of civilizations is no more than that of dandelion seeds. This is disappointing.
On the other hand, as the Universe evolves, the role of mind increases and the role of general physical factors decreases. Take a general physical map or a vegetation map, look at America or Eurasia. Anywhere, well, for example, in the lower third of Eurasia - the zone of forest-steppe and steppe. More precisely, nature is supposed to have a forest-steppe here. In reality, we will find settlements, cities, plowed fields, power lines, ditches and canals, mines, airfields, road lines on the ground ... Actually, there is almost no natural forest-steppe in its pure form. Just like in Europe, the taiga ... Only insects and birds should fly in the air. And there are also planes with helicopters flying ...
Man has long since become a geological force that changes landscapes, as Vernadsky noted. By the way, by noosphere he meant exactly and only this - the influence of man on natural landscapes, and not at all what esotericists and exalted ladies with crimson hair imagine, prone to compiling natal charts and thoughtful reasoning about spirituality and the information field of the planet ...
The influence of intellect as a property of complexly organized matter to transform nature (to change the natural environment to an artificial one) in the world will increase the more the further progress goes. Hence the assumption. Why don't civilizations that appeared in other star systems before us take on the role of a "breeder" or a doctor who artificially increases the "germination" of civilizations? After all, they don’t ask a child in the maternity hospital whether he wants to live or not - they get it, slap on the ass - breathe! And if he can’t, they put him in a pressure chamber and begin to pull him out.
What if we have been watched and guarded for a long time? And they will intervene only as a last resort, over trifles, like Hiroshima and Nagasaki, they will not interfere. There is a reason for this. If the child’s illness is mild, the temperature is not very high, there is no need to bring it down: the body will cope on its own, even a little training of the immune system is useful for it. But if the temperature is very high, they start knocking it down with medicines. So, if we cannot cope on our own, if there is a real danger for the space community to lose the earth civilization as a whole, they will fly in and save us without asking. Slap on the ass - breathe! Or put into a pressure chamber.
A beautiful version, but Nazarethyan aptly called it one of the varieties of religion. Modified in a modern way by a craving for the Father, who, in which case, will come, save, spank ...
He's probably right...
Our beloved blue planet is constantly being hit by space debris, but due to the fact that most space objects burn up or fall apart in the atmosphere, this most often does not pose any serious problems. Even if some object reaches the surface of the planet, it is most often small, and the damage it causes is negligible.
However, of course, there are very rare cases when something very large flies through the atmosphere and in this case very significant damage is inflicted. Fortunately, such falls are extremely rare, but it is worth knowing about them at least in order to remember that there are forces in the Universe that can disrupt the everyday life of people in a couple of minutes. Where and when did these monsters fall to Earth? Let's turn to the geological records and find out:
10. Barringer Crater, Arizona, USA
Arizona apparently lacked the fact that they had the Grand Canyon, so about 50,000 years ago, another tourist attraction was added there when a 50-meter meteorite landed in the northern desert, which left behind a crater 1200 meters in diameter and deep at 180 meters. Scientists believe that the meteorite, which resulted in the formation of a crater, flew at a speed of about 55 thousand kilometers per hour, and caused an explosion more powerful than the atomic bomb dropped on Hiroshima, about 150 times. Some scientists initially doubted that the crater was formed by a meteorite, since the meteorite itself is not there, however, according to modern scientists, the stone simply melted during the explosion, spreading molten nickel and iron around the surrounding area.
Although its diameter is not that big, the lack of erosion makes it an impressive sight. What's more, it's one of the few meteorite craters that looks true to its origin, making it a top-notch tourist destination, just the way the universe wanted it to be.
9. Lake Bosumtwi Crater, Ghana 
When someone discovers a natural lake that is almost perfectly round, it's suspicious enough. That is what Lake Bosumtwi is, reaching about 10 kilometers in diameter, and located 30 kilometers southeast of Kumasi, Ghana. The crater was formed from a collision with a meteorite with a diameter of about 500 meters, which fell to Earth about 1.3 million years ago. Attempts to study the crater in detail are quite difficult, since the lake is difficult to reach, it is surrounded by dense forest, and the local Ashanti people consider it a holy place (they believe that it is forbidden to touch the water with iron or use metal boats, which is why getting to nickel at the bottom of the lake is problematic). Still, it's one of the best-preserved craters on the planet right now, and a good example of the destructive power of megarocks from space.
8. Mistastin Lake, Labrador, Canada 
The Mistatin Impact Crater, located in Canada's Labrador Province, is an impressive 17-by-11-kilometer depression in the earth that formed about 38 million years ago. The crater was likely originally much larger, but has shrunk over time due to the erosion it has undergone due to the many glaciers that have passed through Canada over the past million years. This crater is unique in that, unlike most impact craters, it is elliptical rather than round, indicating that the meteorite hit at an acute angle, rather than level like most meteorite impacts. Even more unusual is the fact that there is a small island in the middle of the lake, which may be the central rise of the complex structure of the crater.
7. Gosses Bluff, Northern Territory, Australia
This 142 million year old and 22 km diameter crater located in the center of Australia is an impressive sight both from the air and from the ground. The crater was formed as a result of the fall of an asteroid with a diameter of 22 kilometers, which crashed into the surface of the Earth at a speed of 65,000 kilometers per hour and formed a funnel almost 5 kilometers deep. The collision energy was about 10 to the twentieth power of Joules, so life on the continent faced great problems after this collision. The highly deformed crater is one of the most significant impact craters in the world and does not let us forget the power of a single large rock.
6. Clearwater Lakes, Quebec, Canada 
Finding one impact crater is cool, but finding two impact craters next to each other is doubly cool. This is exactly what happened when an asteroid broke in two upon entering Earth's atmosphere 290 million years ago, creating two impact craters on the eastern shore of Hudson Bay. Since then, erosion and glaciers have severely destroyed the original craters, but what remains is still an impressive sight. The diameter of one lake is 36 kilometers, and the second is about 26 kilometers. Given that the craters formed 290 million years ago and were heavily eroded, one can only imagine how large they were originally.
5. Tunguska meteorite, Siberia, Russia
This is a controversial point, since no parts of the hypothetical meteorite remained, and what exactly fell into Siberia 105 years ago is not completely clear. The only thing that can be said with certainty is that something large and moving at high speed exploded near the Tunguska River in June 1908, leaving behind fallen trees over an area of 2000 square kilometers. The explosion was so strong that it was recorded by instruments even in the UK.
Due to the fact that no pieces of the meteorite were found, some believe that the object may not have been a meteorite at all, but a small part of a comet (which, if true, explains the absence of meteorite fragments). Fans of conspiracies believe that an alien spaceship actually exploded here. Although this theory is completely unfounded and is pure speculation, we have to admit that it sounds interesting.
4. Manicouagan Crater, Canada 
The Manicouagan Reservoir, also known as the Eye of Quebec, is located in a crater formed 212 million years ago when an asteroid 5 kilometers in diameter hit Earth. The 100-kilometer crater that was left after the fall was destroyed by glaciers and other erosive processes, but even at the moment it remains an impressive sight. What is unique about this crater is that nature did not fill it with water, forming an almost perfectly round lake - the crater basically remained land surrounded by a ring of water. A great place to build a castle here.
3. Sudbury Basin, Ontario, Canada 
Apparently, Canada and impact craters are very fond of each other. Singer Alanis Morrisette's hometown is a favorite place for meteorite impacts - the largest meteorite impact crater in Canada is located near Sudbury, Ontario. This crater is already 1.85 billion years old, and its dimensions are 65 kilometers long, 25 wide and 14 deep - 162 thousand people live here, and many mining enterprises are located, who discovered a century ago that the crater is very rich in nickel due to for the fallen asteroid. The crater is so rich in this element that about 10% of the world's nickel production is obtained here.
2. Chicxulub Crater, Mexico
Perhaps the fall of this meteorite caused the extinction of the dinosaurs, but this is definitely the most powerful collision with an asteroid in the entire history of the Earth. The impact occurred about 65 million years ago, when an asteroid the size of a small city crashed into Earth with an energy of 100 teratonnes of TNT. For those who like hard data, that's roughly 1 billion kilotons. Compare this energy with the 20 kiloton atomic bomb dropped on Hiroshima and the impact of this collision becomes clearer.
The impact not only created a 168-kilometer diameter crater, but also caused megatsunamis, earthquakes, and volcanic eruptions all over the Earth, greatly altering the environment and dooming the dinosaurs (and apparently a lot of other creatures). This vast crater, located on the Yucatan Peninsula near the village of Chicxulub (after which the crater was named), can only be seen from space, which is why scientists discovered it relatively recently.
1. Vredefort Dome Crater, South Africa
Although the Chicxulub crater is better known, compared to the 300 kilometers wide Vredefort crater in the Republic of South Africa, it is a common pothole. Vredefort is currently the largest impact crater on Earth. Fortunately, the meteorite / asteroid that fell 2 billion years ago (its diameter was about 10 kilometers) did not cause significant harm to life on Earth, since multicellular organisms did not yet exist at that time. The collision no doubt greatly changed the climate of the Earth, but there was no one to notice it.
At the moment, the original crater is heavily eroded, but from space, its remnants look impressive and are a great visual example of how scary the universe can be.
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.
The development of technologies, with the help of which it became possible to study the cosmos in detail, allowed mankind to learn a lot of information about the space surrounding our planet. As it turned out, many objects move around the Earth: these are not only stars, there are a large number of smaller celestial bodies, called asteroids. But, despite the fact that in size they cannot be compared even with the smallest of the known planets, for humanity they are the most dangerous space formations. Moreover, history knows asteroids that hit the earth in the past.
Recently, reports about objects that may soon collide with the Earth began to appear in the media with noticeable periodicity. In 2013, Apophis, listed in the Guinness Book of Records as the most dangerous asteroid, approached the Earth. Today, the Internet is replete with reports of an approaching celestial body called Florence. However, scientists report: this time everything will go fine and there will be no collision.
But the approach of bodies to our planet does not always end so happily. Some of them still overcome the atmosphere and fall to the earth's surface.
Asteroids that have fallen to earth. Huge crater in Africa
Photo: Economictimes.indiatimes.comWhen the solar system was very young, collisions of objects of different sizes were not uncommon. The proof of this is the surface of the Moon and the planets, which lack a “natural shield” – the atmosphere.
Our planet has also seen many such disasters in its lifetime. Traces of the most ancient of them were discovered by scientists. The cosmic body that “kissed” the Earth 3.3 billion years ago was truly gigantic in size - its diameter was about 50 km. For comparison, the famous Apophis, which humanity feared quite recently, is only 250-400 meters in diameter.
Photo: antikleidi.com An asteroid that fell in South Africa caused enormous destruction. The shift of tectonic plates, an earthquake that reached a power of 10 points, a tsunami, the earth's surface burned for thousands of kilometers - terrifying phenomena, evidence of which scientists still find.
Asteroids that have fallen to earth. Sudbury is Canada's source of wealth
Photo: Roogirl.com The "space bomb", which hit the Earth about 1.8 billion years ago, pierced the earth's crust to the mantle, turning the inner layers to the surface. Its fragments scattered over a great distance.
But the modern inhabitants of the planet, born much later than the catastrophe that occurred, were even able to benefit from the collision. The Sudbury region is one of the largest mineral deposits in Canada. And the soil, rich in minerals left behind by magma, is ideal for agriculture.
Asteroids that have fallen to earth. Chiklusub - Death of the Dinosaurs
Photo: Isbn-10.xyz 66 million years ago, the Earth was very different from what we see today. It was inhabited by creatures that can now only be found in films. At that time, dinosaurs were the masters of the planet.
For a long time, no one could understand what caused the extinction of the dominant species at that time. And only in the 20th century it was suggested that the disappearance of many thousands of living beings is a consequence of the fall of a huge celestial body. 
Photo: Dinocreta.com
It is believed that the Earth collided with a very large asteroid. A blow of enormous force provoked many catastrophes that led to the almost complete disappearance of life. Of course, a small part of living beings (mostly small in size) was able to adapt to the dramatically changed conditions. But the dinosaurs are gone forever.
The place where the asteroid fell is a crater located near the city of Chiklusub, which received the same name as this settlement. Judging by its size, the body that collided with the ground had a diameter of 10 km.
Asteroids that have fallen to earth. Tunguska meteorite - the mystery of the century
Photo: baricada.ro At the beginning of the 20th century, or rather in 1908, a space object rushed to the surface of the earth, which later became known as the Tunguska meteorite. Residents of settlements located in the immediate vicinity of the crash site could observe many unusual phenomena associated with this event: nights as bright as day, thunder in a cloudless sky and a grandiose explosion.
But the crater from the fall of a celestial body could not be found. This fact caused a great resonance in the scientific community. Scientists have put forward many theories, ranging from the landing of an alien ship to the fall of an icy comet. None of them has yet been recognized as official.
Asteroids that have fallen to earth. Chelyabinsk disaster
Photo: News.pn An unexpected event happened on February 15, 2013. An unnoticed asteroid flew up to the Earth and collided with its surface near Chelyabinsk, one of the largest industrial centers of Russia.
Photo: Chinadaily.com.cn The fact that the appearance of this celestial object was not predicted by scientists is explained by the fact that it flew up to our planet from the side of the Sun, and it was impossible to notice it with a telescope. It's scary to even think what would happen if the dimensions of the asteroid were not 6 m in diameter, but much larger. Indeed, even the explosion of such a relatively small cosmic body is several dozen times greater than the explosion of a nuclear bomb dropped on Hiroshima, although its consequences were not so catastrophic.
Often the onset of the end of the world is associated precisely with a collision with a large asteroid. It remains to be hoped that mankind will never see such a catastrophe. But, given the number of objects that annually fly dangerously close to the Earth, the likelihood that someday a large meteorite will still crash into it is very high.
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