Astrophysicists from Canada claim that the mass of the flow of meteorites 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 habitat 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 a person or are not at all suitable for habitation. Therefore, finding a meteorite is a great success. However, there was a case when a meteorite itself found a person.
Case of a collision of a meteorite with a person
In the entire history of the fall of celestial bodies on 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, damaged the leg of the hostess. This means that there is still a risk that a more serious guest from outer space may fall on human heads. I wonder what the largest meteorite fell on our planet?
Meteorites are divided into three categories: stone, iron stone and iron. And in each of these categories there are giants.
The largest stone meteorite
More recently, on March 8, 1976, space presented the Chinese with a gift in the form of meteor shower. Stones fell to the surface of the earth within 37 minutes. One of the fallen specimens had a weight of 1.77 tons. It was the largest meteorite that fell to the ground, 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 meteorite made of stone found on earth.
The largest iron-stone meteorite
The largest representative from the category of iron-stone meteorites weighed 1.5 tons. Found him in 1805 in Germany.
A fellow German meteorite found in Australia weighed only 100 kg less than German.
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 a weight of over 66 tons was discovered in the south-west of Namibia! Larger than this instance on our planet have not yet been found. It turned out to be the largest meteorite that fell on Earth. The name was given to him in honor of the Goba West farm, the owner of which came across him during the cultivation of the field. The approximate age of the iron block is 80 thousand years.
Today, the Goba meteorite is the largest solid block of natural iron.
In 1955, the largest meteorite that fell to the ground, the Goba, was declared a national monument and taken under state protection. This was a necessary measure, since for 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 "losing weight" was made by numerous tourists. Now you can approach the celestial body only under the supervision and for a fee.
The meteorites mentioned above, of course, are the largest in their category of all previously discovered. But the question of which largest meteorite fell to the ground remained open.
Meteorite that killed the dinosaurs
Everyone knows the sad story of the extinction of dinosaurs. Scientists still argue about the cause of their death, but the main version remains that the meteorite became the culprit of the tragedy.
According to scientists, 65 million years ago, the Earth was hit by a huge meteorite, which caused a catastrophe on a planetary scale. The meteorite fell on the territory that now belongs to Mexico - the Yucotan Peninsula, near the village of Chixulub. An evidence of this fall was the impact crater found in 1970. But since the trench was covered with sedimentary rocks, they did not begin to carefully examine the meteorite. And only after 20 years, scientists returned to its study.
As a result of the work, it turned out that the funnel left by the meteorite has 180 km in diameter. The diameter of the meteorite itself was about 10 km. The impact energy during the fall was 100,000 Gt in TNT equivalent (this is comparable to the simultaneous explosion of the 2,000,000 largest thermonuclear charges).
It is assumed that a tsunami formed as a result of a meteorite impact, while the wave height varied from 50 to 100 meters. The dust particles raised by the impact for several years tightly closed the Earth from the Sun, which led to a sharp change in climate. Acid rain and periodic large-scale fires exacerbated the situation. An analog of nuclear winter has come on the planet. As a result of the disaster, 75% of the species of animals and plants became extinct.
Nevertheless, officially the Chiksulubsky meteorite is the largest meteorite that fell to the earth 65 million years ago. He practically destroyed all life on the planet. But in the history of the fall of meteorites on Earth in its size, it occupies only third place.
The first among the giants
Presumably 2 billion years ago, a meteorite fell on Earth, which left a 300 km diameter track on its surface. The meteorite itself supposedly had a diameter of more than 15 km.
The crater remaining after the fall is located in South Africa, in the Free State province, and is called Wredefort. This is the largest impact crater, and left it the largest meteorite that fell to Earth in the history of our planet. In 2005, the Wredefort crater was listed as a UNESCO World Heritage Site. The largest meteorite that fell to Earth did not leave a memory photo, but a huge scar in the form of a crater on the surface of our planet will not allow it to be forgotten.
It is noted that the fall of meteorites, the dimensions of which are measured at least tens of meters, occurs with a frequency 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 received the name Apophis (the so-called snake god, who was the antipode of the sun god Ra in ancient Egypt). It falls to Earth or misses yet and passes near the planet, it is not known for certain. But what happens if, after all, a collision does occur?
Apophis collision scenario with 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 power to 15,000 bombs dropped on Hiroshima.
If Apophis lands in the mainland, there will be an impact crater having a depth of 400-500 meters and a diameter of up to 5 km. The resulting shock wave will destroy capital structures 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 pillar of dust rises to a height of several kilometers and then covers the entire planet.
The stories spread by the media about nuclear winter and the end of the world are too exaggerated. The size of the meteorite for such consequences is too small. It is possible to lower the temperature by 1-2 degrees, but even after six months it will return to normal. That is, the foreshadowed catastrophe, if it does happen, will be far from global.
If Apophis falls into the ocean, it is more likely that a tsunami will occur that will cover the coastal areas. The wave height in this case will depend on the distance between the coast and the meteorite’s place of impact. The initial wave can have a height of up to 500 meters, but if Apophis falls in the center of the ocean, then the wave reaching 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 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 excluded the probability of a meteorite colliding with the ground. As for 2036, today the chance of a collision of a meteorite with the Earth is 1: 250 000. And every year, as the accuracy of calculations increases, the probability of collision decreases.
But even with this probability, various options are considered for forcing Apophis to deviate from the course. Thus, Apophis is an object that is more of an interest than a threat.
In conclusion, I want to note that meteorites when entering the atmosphere of the earth are greatly destroyed. When approaching the Earth, the speed of fall of guests from outer space is 10-70 km / s, and in contact with the gas atmosphere, which has a fairly high density, the meteorite temperature rises to critical, and it simply burns out or very much collapses. Thus, the atmosphere of our planet is the best protector from uninvited guests.