Asteroids, which in the future may approach the Earth at a distance equal to 7.5 million km, are considered potentially dangerous for the Earth. Our planet has more than once collided with these cosmic bodies. Today we will talk about how dangerous the fall of an asteroid to Earth is and is there a possibility of a large-scale catastrophe in the foreseeable future? Let's start with a little historical background.
An asteroid (from the Greek "star-like", "star") is also called a minor planet. It is a celestial body, the size of which exceeds 30 km. Some of them have their own satellites. Many asteroids travel across our solar system. 3.5 million years ago, a huge number of asteroids fell to Earth, which led to global changes.
Traces of an ancient asteroid
In the spring of 2016, in Australia, geologists discovered traces of the fall of an asteroid, the diameter of which was about 30-40 km. That is, in size it is commensurate with a small satellite. The fall caused an 11-magnitude earthquake, tsunami and massive destruction. It was probably one of the asteroids, as a result of which not only the beginnings of life were formed on the earth, but also the entire diversity of the biosphere was formed.
There is also an opinion that the mysterious disappearance of dinosaurs was due to the fall of a large asteroid to Earth. Although this is just one of many versions...
It is interesting! The ancient shock was formed as a result of a meeting with a meteorite. Its depth once reached 20 km. The fall of the meteorite caused a tsunami and climate change similar to nuclear winter. In addition, for up to 16 years on Earth, the temperature could drop by 26 degrees.
Chelyabinsk meteorite
The fall of an asteroid to Earth in February 2013 has become one of the most discussed incidents not only in Russia, but throughout the world. The asteroid, whose mass reached 16 tons, partially burned up in the Earth's atmosphere, but a relatively small part of it fell near Chelyabinsk, fortunately flying over it.
In that year, he flew over the Ural city, which served as the basis for his name. The body itself turned out to be quite ordinary and consisted of chondrites, but the time and place of its fall aroused interest. None of the asteroids that fell to Earth did such damage, since they did not fall in such close proximity to a densely populated area. The mass of the meteorite was 6 tons. Falling into the lake caused broken glass in 7,000 buildings. 112 people were hospitalized with burns, several more people turned to doctors for help. In total, the shock wave covered 6.5 thousand square meters.
The huge damage caused by the asteroid could have been much more significant if the heavenly stone had fallen not into the water, but onto land. Fortunately, the fall of the asteroid to earth did not turn into a large-scale catastrophe.
How dangerous is the fall of a large meteorite to Earth?
According to the calculations of scientists, the fall of an asteroid to Earth can lead to huge damage if a body about 1 km in size falls on the Earth's land. First of all, a funnel with a diameter of about 15 km is formed, this will cause dust to enter the atmosphere. And this, in turn, can lead to large-scale fires. Dust, heated by the sun, will reduce the level of ozone, accelerate chemical reactions in the stratosphere, reduce the amount of sunlight reaching the surface of the planet.
Thus, the consequences of an asteroid falling to Earth are very serious. The global temperature of the Earth will fall by 8 0 C, causing an ice age. But in order to cause the extinction of mankind, the asteroid must be 10 times larger.
Giant danger
Recently, scientists have found that centaurs should be included in the list of potential threats to our planet - these are giant asteroids with a diameter of 50 to 100 km. The gravitational field of other planets every 40-100 thousand years throws them towards our Earth. Their number has now increased dramatically. Is it possible for a giant asteroid to fall to Earth in the near future, scientists are constantly calculating, although calculating the trajectory of the fall of centaurs is a very difficult task.
In addition, the list of potential threats to the Earth includes:
- supervolcanic eruption;
- global pandemic;
- asteroid impact (in 0.00013%);
- nuclear war;
- ecological catastrophy.
Will an asteroid hit Earth in October 2017?
The main issue that currently worries scientists is the danger posed by an asteroid, the size of which is 2 times larger than the Chelyabinsk meteorite. There is a possibility that an event will occur in October 2017 that will cause a much larger scale of disaster than the impact in 2013. Astronomer Judith Rees claims that the diameter of the asteroid reaches 40 km. It was dubbed object WF9.
A dangerous celestial body was discovered by scientists in Hawaii back in 2012. That year, it passed at a very close distance from the Earth, and on October 12, 2017, it will approach the most dangerous distance for our planet. Scientists believe that if the fall of the asteroid to Earth really takes place, then the British will be the first to see it.
At the moment, scientists are actively studying the possibility of a collision. True, the probability of an asteroid falling to Earth is very small and, according to researchers, is 1 in a million. However, it is still there.
Constant danger
It should be noted that certain asteroids of various sizes constantly fly past the Earth. They are potentially dangerous, but very rarely actually fall to Earth. So, at the end of 2016, a body flew past the Earth at a distance of 2/3 of the distance from a small truck.
And January 2017 was marked by the passage of a celestial body reaching the size of a 10-story building. He flew within 180 thousand km from us.
Space bodies are constantly falling on our planet. Some of them are the size of a grain of sand, others can weigh several hundred kilograms and even tons. Canadian scientists from the Ottawa Astrophysical Institute claim that a meteor shower with a total mass of more than 21 tons falls on Earth every year, and individual meteorites weigh from a few grams to 1 ton.
In this article, we will recall the 10 largest meteorites that fell to Earth.
Meteorite Sutter Mill, April 22, 2012
This meteorite called Sutter Mill appeared near the Earth on April 22, 2012, moving at a breakneck speed of 29 km / s. It flew over the states of Nevada and California, scattering its red-hot fragments, and exploded over Washington. The power of the explosion was about 4 kilotons of TNT. For comparison, yesterday's capacity was 300 kilotons of TNT.
Scientists have found that the Sutter Mill meteorite appeared in the early days of its existence, and the cosmic progenitor body was formed over 4566.57 million years ago.
Almost a year ago, on February 11, 2012, about a hundred meteorite stones fell over an area of 100 km in one of the regions of China. The largest meteorite found weighed 12.6 kg. The meteorites are believed to have come from the asteroid belt between Mars and Jupiter.
Meteorite from Peru, September 15, 2007
This meteorite fell in Peru near Lake Titicaca, near the border with Bolivia. Eyewitnesses claimed that at first there was a loud noise, similar to the sound of a falling plane, but then they saw a certain falling body, engulfed in fire.
A bright trail from a cosmic body heated to white heat that entered the Earth's atmosphere is called a meteor.
A crater 30 meters in diameter and 6 meters deep formed at the site of the fall from the explosion, from which a fountain of boiling water gushed. The meteorite probably contained poisonous substances, as 1,500 people living nearby developed severe headaches.
By the way, most often stone meteorites (92.8%), consisting mainly of silicates, fall to the Earth. , was iron, according to the first estimates.
Meteorite Kunya-Urgench from Turkmenistan, June 20, 1998
The meteorite fell near the Turkmen city of Kunya-Urgench, hence its name. Before the fall, the inhabitants saw a bright light. The largest part of the meteorite, weighing 820 kg, fell into a cotton field, forming a funnel about 5 meters.
This one, over 4 billion years old, has been certified by the International Meteoritic Society and is considered the largest among stone meteorites from all fallen in the CIS and the third in the world.
Fragment of the Turkmen meteorite:
Meteorite Sterlitamak, May 17, 1990
Iron meteorite Sterlitamak weighing 315 kg fell on a state farm field 20 km west of the city of Sterlitamak on the night of May 17-18, 1990. When a meteorite fell, a crater with a diameter of 10 meters was formed.
First, small metal fragments were found, and only a year later, at a depth of 12 meters, the largest fragment weighing 315 kg was found. Now the meteorite (0.5 x 0.4 x 0.25 meters) is in the Museum of Archeology and Ethnography of the Ufa Scientific Center Russian Academy Sciences.
Fragments of a meteorite. On the left is the same fragment weighing 315 kg:
The largest meteor shower, China, March 8, 1976
In March 1976, the world's largest meteorite rock shower took place in the Chinese province of Jilin, lasting 37 minutes. Space bodies fell to the earth at a speed of 12 km/sec.
Fantasy on the theme of meteorites:
Then they found about a hundred meteorites, including the largest - the 1.7-ton Jilin (Girin) meteorite.
These are the pebbles that rained down from the sky on China for 37 minutes:
Meteorite Sikhote-Alin, Far East, February 12, 1947
The meteorite fell on Far East in the Ussuri taiga in the Sikhote-Alin mountains on February 12, 1947. It was crushed in the atmosphere and fell out in the form of iron rain over an area of 10 sq. km.
After the fall, more than 30 craters with a diameter of 7 to 28 m and a depth of up to 6 meters were formed. About 27 tons of meteorite material was collected.
Pieces of iron that fell from the sky during a meteor shower:
Goba meteorite, Namibia, 1920
Meet Goba - largest meteorite ever found! Strictly speaking, it fell about 80,000 years ago. This iron giant weighs about 66 tons and has a volume of 9 cubic meters. fell in prehistoric times, and was found in Namibia in 1920 near Grotfontein.
The Goba meteorite is mainly composed of iron and is considered the heaviest of all celestial bodies of this kind that have ever appeared on Earth. It is preserved at the crash site in southwestern Africa, in Namibia, near the Goba West farm. It is also the largest piece of iron of natural origin on Earth. Since 1920, the meteorite has decreased slightly: erosion, Scientific research and vandalism did their job: the meteorite "lost weight" to 60 tons.
The mystery of the Tunguska meteorite, 1908
On June 30, 1908, at about 07:00 in the morning, a large fireball flew over the territory of the Yenisei basin from the southeast to the northwest. The flight ended with an explosion at an altitude of 7-10 km above the uninhabited area of the taiga. The blast wave doubled Earth and has been recorded by observatories around the world.
The explosion power is estimated at 40-50 megatons, which corresponds to the energy of the most powerful hydrogen bomb. The flight speed of the space giant was tens of kilometers per second. Weight - from 100 thousand to 1 million tons!
Area of the Podkamennaya Tunguska River:
As a result of the explosion, trees were knocked down over an area of more than 2,000 square meters. km, window panes in houses were broken several hundred kilometers from the epicenter of the explosion. Animals were destroyed by the blast wave within a radius of about 40 km, people were injured. For several days, an intense glow of the sky and luminous clouds were observed in the territory from the Atlantic to central Siberia:
But what was it? If it was a meteorite, then a huge crater half a kilometer deep should have appeared at the site of its fall. But none of the expeditions could find him ...
The Tunguska meteorite is, on the one hand, one of the most well-studied phenomena, on the other hand, one of the most mysterious phenomena of the past century. The celestial body exploded in the air, and no remnants of it, except for the consequences of the explosion, were found on the ground.
Meteor shower of 1833
On the night of November 13, 1833 over eastern territory The United States has experienced a meteor shower. It went on continuously for 10 hours! During this time, about 240,000 meteorites of various sizes fell to the Earth's surface. The meteor shower of 1833 was the most powerful meteor shower known. Now this stream is called the Leonids in honor of the constellation Leo, against which it is visible every year in mid-November. On a much smaller scale, of course.
In 1790, the fall of a meteorite to Earth was recorded for the first time. True, scientists from the Paris Academy of Sciences recognized the fact of the collision of a comic body with the surface of our planet only 13 years later, at first considering the testimony of three hundred eyewitnesses as a joke. In this collection - the most sensational meteorites in the history of mankind.
Goba: the largest meteorite ever found (Namibia)
The largest meteorite found weighs more than 60 tons, and its diameter is about 3 meters. He fell into the territory of modern Namibia, presumably 80 thousand years ago. The celestial body was discovered relatively recently - in 1920, the owner of the Hoba West Farm, located in the southwest of the country, stumbled upon a huge piece of iron while plowing one of his fields. In honor of the farm, the find was named.
Composed of 84% iron, the meteorite is considered the largest nugget of this metal found on Earth. In order to prevent vandalism, in 1955 it was declared a national monument, because since the discovery, the mass of Gob has decreased by 6 tons. In 1987, the owner of the farm donated the meteorite and the land on which it is located to the state, and now the government of Namibia monitors its safety.
Allende: the most studied among meteorites (Mexico)
The unsuspecting residents of the city of Chihuahua woke up around one in the morning on February 8, 1969. They were awakened by noise and a bright flash resulting from the fall of a 5-ton meteorite. A lot of fragments scattered over tens of kilometers, the total weight of which is estimated at 2-3 tons. The collected pieces "scattered" around the institutes and museums of the world.
Scientists say that Allende (Spanish: Allende) is the largest and most studied of the recorded carbonaceous meteorites. The report of American astrophysicists from the Livermore National Laboratory of the US Department of Energy states that the age of calcium-aluminum inclusions, which are rich in meteorite, is approximately 4.6 billion years, that is, more than the age of any of the planets in the solar system.
Murchison meteorite: the most "alive" meteorite found on Earth (Australia)
Named after the Australian city near which it fell in 1969, the Murchison meteorite is believed to be the most "alive" meteorite found on Earth. This is due to more than 14 thousand organic compounds that make up the 108-kilogram carbonaceous stone, including at least 70 different amino acids.
Research led by Philipp Schmitt-Koplin of the Institute for Environmental Chemistry in Germany claims that the meteorite contains millions of different kinds of organic molecules, which proves the existence of amino acids outside of our planet. According to scientists, the age of the meteorite is 4.65 billion years, that is, it was formed before the appearance of the Sun, whose age is estimated at 4.57 billion years.
Sikhote-Alin meteorite: one of the largest observed during the fall (Russia)
One of the largest meteorites in the world fell in Primorsky Krai in the Sikhote-Alin mountains in February 1947. The dazzling fireball he caused was observed in Khabarovsk and other settlements within a radius of 400 km. An iron body weighing 23 tons disintegrated in the atmosphere into many fragments in the form of a meteor shower.
The fragments formed on the surface of the Earth more than 30 craters from 7 to 28 m in diameter and up to 6 meters deep. The largest fragment of the Sikhote-Alin meteorite weighs about 1,745 kg. The pilots of the Far Eastern Geological Administration were the first to report the place where the celestial body fell. Chemical analysis showed 94% iron in the composition of the meteorite.
ALH84001: the most famous Martian meteorite (Antarctica)
This name hides perhaps the most famous of the 34 Martian meteorites found on Earth. It was discovered on December 27, 1984 in the Alan Hills mountains in Antarctica (the name of the mountains is recorded in the name with a three-letter abbreviation). According to studies, the age of the alien body is from 3.9 to 4.5 billion years. A meteorite weighing 1.93 kg fell to Earth about 13 thousand years ago.
There is a hypothesis according to which it broke away from the surface of Mars during the collision of the planet with a large cosmic body. In 1996, NASA scientists published sensational data suggesting the existence of traces of life on Mars. When scanning meteorite structures with a raster electron microscope microscopic structures have been identified that can be interpreted as petrified traces of bacteria.
Tunguska meteorite: the most "powerful" meteorite (Russia)
One of the world's most famous meteorites hit the Earth in 1908, exploding at an altitude of 5 - 7 kilometers above Eastern Siberia. An explosion with a capacity of 40 megatons knocked down trees on an area of more than 2 thousand square kilometers near the Podkamennaya Tunguska River. Its blast wave circled the globe twice, leaving behind a glow in the sky for several days. In addition, a series of consequences of the cataclysm was completed by a powerful magnetic storm that lasted five hours.
Several Italian scientists have hypothesized that the Tunguska crater may be Lake Cheko on the Kimchu River, which is located 8 km northwest of the epicenter of the explosion.
Lake Cheko on the Kimchu River
Chelyabinsk meteorite: No. 2 after Tunguska (Russia)
According to NASA estimates, the Chelyabinsk meteorite is the largest known celestial body that fell to Earth after the Tunguska meteorite. They started talking about him on February 15 and do not stop discussing six months later. Exploding in the sky above Chelyabinsk at an altitude of 23 km, the meteorite caused a powerful shock wave, which, as in the case of the Tunguska meteorite, circled the globe twice.
Before the explosion, the meteorite weighed about 10 thousand tons and had a diameter of 17 meters, and after that it broke into hundreds of fragments, the largest of which weighed half a ton. The space guest, who brought world fame to the region, is planned to be immortalized in the form of a monument.
A fragment of the Chelyabinsk meteorite found near Yemanzhelinsk. Weight is 112.2 g.
TASS-DOSIER. On December 6, 2016, a meteorite exploded in the sky over Khakassia. Three flashes were recorded, the rumble was heard in the Abakan region.
According to Viktor Grokhovsky, a member of the Committee on Meteorites of the Russian Academy of Sciences, Professor of the Ural Federal University, the meteorite is several times smaller than its Chelyabinsk "brother" that fell in February 2013 into Lake Chebarkul.
Meteorites are solid natural bodies of cosmic origin that fall on the surface of a large celestial object eg planets. They can consist of minerals (stone meteorites), metals (iron) and be of a mixed type (iron-stone).
The surface of the Earth reaches 9% of the mass of all meteorites. According to a number of scientists, every year a meteorite storm with a total mass of approximately 21.3 tons falls on our planet. According to statistics, only one out of 100 thousand meteorites has destructive power. Most of the meteorites found on Earth have a mass of several grams to several kilograms.
Most often, meteorites fall in Antarctica: according to experts, about 700 thousand of them are scattered on the mainland. There is also the largest accumulation of meteorites on a limited area of \u200b\u200bthe surface, discovered in 1979. The most massive meteorite - weighing more than 60 tons - was found in Namibia in 1920 g., he received the name Goba.
Cases of meteorites falling on settlements extremely rare: only a few such facts are known. At the same time, only twice falling celestial bodies injured people (1954, Alabama, USA; 2004, Great Britain).
The first reliably recorded fall of a meteorite in world history dates back to November 16, 1492. This happened near the French village of Ensisheim in the Upper Rhine region. The stone that fell from the sky weighed about 127 kg. His fall was witnessed by numerous eyewitnesses, including the famous German artist and graphic artist Albrecht Dürer. He sketched this event on a small wooden board measuring 23x17 cm.
Chronology of five known cases of the fall of large meteorites in the XX - XXI centuries
June 30, 1908 over the river basin. Podkamennaya Tunguska in Eastern Siberia, a meteorite fell, which later received the name "Tunguska". As a result, in the air, when a celestial body entered the dense layers of the atmosphere, an explosion occurred with a power of about 50 Mt in TNT equivalent. The shock wave devastated up to 2 thousand square meters. km. To date, more than 5 thousand fairly large fragments of the Tunguska meteorite have been found.
On February 12, 1947, a meteorite with a mass of more than 23 tons was recorded in the Primorsky Territory (one of the ten largest in the world). It was called the Sikhote-Alin by the name of the mountains, over which the meteorite fell like iron rain over an area of 35 square meters. km.
On March 8, 1976, a meteorite weighing over 4 tons fell in northeast China. It was named Kirin.
On February 8, 1969, the Allende meteorite fell in northern Mexico. As it fell, it shattered into many pieces. Collected about 2-3 tons of fragments. Allende is considered the largest carbonaceous meteorite found on Earth.
On February 15, 2013, a meteorite fell near Chebarkul Lake in the Chelyabinsk Region, officially called "Chelyabinsk" (also known as "Chebarkulsky"). The meteor shower was observed by residents of five regions of Russia at once - Tyumen, Sverdlovsk, Chelyabinsk, Kurgan regions and Bashkiria. Most of the fragments fell into the lake. In October 2013, fragments with a total weight of 654 kg were raised from Chebarkul, in March 2014, the largest fragment weighing several tons was found at the bottom of the lake.
It is possible to answer this global question only with a stretch, and even then in the subjunctive mood: "If ...". The past year has been replete with astronomers' predictions on this subject. It was planned for February by the American department NASA the fall of a giant asteroid. Probably into the ocean, because it will cause a supertsunami. And closer to Great Britain, exciting seaside residents.
What didn't happen in 2017?
So, this “if” meant that the space alien would either miss our Planet, or the fall would destroy the city. It passed: a terrible stone flew by. But for some reason, only NASA knew about the threat. Then they scared earthlings in March, October and December. In March, an asteroid hundreds of times larger than Chelyabinsk should land on the cities of Europe. In October, the asteroid TS4 flew up with a diameter of 10 - 40 meters. If the smaller one, it will go unnoticed, and the larger one will leave a giant crater on the surface.
Astronomers on such bodies give approximate sizes on which the threat to us depends. And they are not blind, because asteroids glow in flight, and this hides their size. In the atmosphere, they partially burn out, losing mass.
You better fly on
But all the asteroids and meteoroids, fortunately, flew past Mother Earth. Or they lost significant weight in the atmosphere, turning into meteor showers, harmless and called "starfall". As happened with the December meteoroid, which could fall somewhere in the region of Nizhny Novgorod, Kazan or Samara. By the way, the infamous Chelyabinsk meteoroid (February 2013) flew almost along this trajectory, and the Yekaterinburg meteorite also. Space rocks love this route!
Not all of them fly with a final stop on Earth, but many fly tangentially, hundreds of thousands of kilometers away from it. To celestial bodies, migrating through the Universe, astronomers and astrophysicists are closely watching, because the orbits of the flight are changing. And after some time they can turn to visit us.
When a meteorite will fall to Earth (video)
2018 is no exception for the fall of asteroids or meteoroids to Earth. It is difficult to predict this phenomenon in advance. As astronomers say, one can accurately predict the fall when it enters the layers of the atmosphere and begins to break up into meteor showers. If you look at the calendar of "starfalls" for the current year, then it is no less than a year ago. Which of them will appear from asteroids dangerous for earthlings is still only a guess.