The likelihood that it will specifically kill you with a meteorite is negligible, although several cases of space stones hitting buildings, cars and people have been officially recorded. On the other hand, the probability that humanity will someday be destroyed by a crazy asteroid tends to unity. Moreover, in the history of the Earth there have already been cases when space aliens became the causes of mass extinctions, which significantly thinned the "population" of the planet. Where on the Earth's surface can you find scars from cosmic catastrophes and what are the consequences of falling meteorites in the past?
Why are there fewer craters on Earth than on the Moon?
There are fewer visible meteorite craters on Earth than on the Moon, Mars, satellites of giant planets and large asteroids. Significantly less. Nevertheless, the Earth is bombarded by meteorites just as often as its natural satellite. According to astronomers' calculations, hundreds of meteorites with a total mass of 5-6 tons fall to the Earth every day, which gives a total of 2 million kg of celestial stones every year.
The most famous meteorite crater on Earth is Arizona. He is only 50 thousand years old
Only some of the space guests reach the planet's surface. Most small to medium sized meteorites burn up in the atmosphere, leaving a beautiful streak of fire across the night sky. Larger stones lose speed and simply fall to the ground without causing significant damage. But there are also catastrophes in the history of the Earth that are remembered for a long time, such as the well-known fall of a meteorite on Podkamennaya Tunguska in June 1908.
Herschel's huge crater makes Mimas, the moon of Saturn, very popular with Star Wars fans
Promotional video:
Meteorite fall map from 2300 BC to 2013 The size of the point corresponds to the mass of the object
Approximately once every 4 years, a meteorite with a diameter of about 10 m falls to the Earth. Once a millennium, a larger "present" arrives - an asteroid up to 100 m. "Stones" 1 km fall once every 250 thousand years, and once every 70 million years the Earth " lucky "to catch a celestial body with a diameter of 10 km. It would seem that only these huge meteorites in the long history of the Earth should have completely covered the planet's surface with craters of considerable size. So where are the tracks?
Hundreds of meteorites with a total mass of 5-6 tons fall to the Earth every day, that is, up to 2 million kg of "stones" per year
Unlike our celestial neighbors, the Earth has an atmosphere, which means winds, rains, snows and other hurricanes are free cosmetologists of the planet. For millennia, and even more so for a million years, erosion phenomena can not only "hide" a meteorite crater of any size, but also erase whole mountain ranges into sand. Do not forget about sedimentary rocks - many impact craters are simply buried under a hundred or more meters of organic sediments. Even less fortunate were the meteorites that fell into the water, which, I recall, covers 71% of the earth's surface - their traces can no longer be found, disappeared into the abyss. Plus other masking factors: the movement of tectonic plates, volcanic eruptions, mountain building processes, etc., etc.
The relatively young Pingahualuit impact crater in Canada. Diameter - 3.44 km. Age - about 1.4 million years
In short, meteorite craters on Earth are perfectly camouflaged. And if traces of small meteorites that have recently fallen on a geological scale can still be found, then the scars left by large celestial bodies millions of years ago are still the subject of controversy among scientists. Let's get acquainted with the most famous and largest meteorite craters on Earth.
Old scars of the Earth
To designate large, more than 2 km in diameter, impact craters on the Earth's surface, the beautiful word astroblema is used. The Planetary and Space Science Center (PASSC) in Canada, which maintains the Earth Impact Database (EID), is responsible for the classification and accounting of impact craters on Earth. Until scientists come to a consensus about the origin of the crater or the geological structure, it will not be listed in the EID. The largest officially confirmed astroblem, according to PASSC, is Vredefort Crater in South Africa, with a diameter of 160 km from ridge to ridge. Moreover, if we consider all the geological structures affected by the impact, the diameter of the same Vredefort can be taken as 300 km. We will indicate the maximum crater size.
The largest crater in the solar system is located on Mars. This is the North Polar Basin, which occupies about 40% (!) Of the planet's surface. It is assumed that the crater was left by a huge asteroid with a diameter of 1600-2700 km, moving at a low speed of 6-10 km / s. In fact, it was a collision of two planets.
The largest crater in the solar system is located on Mars and occupies 40% (!) Of the planet's surface
But back to Earth. Below we take a look at the most interesting of the large impact craters.
Warbarton Basin (Australia, diameter 400 km)
Warbarton Basin Map
The most recent discovery by scientists yet not included in the Earth Impact Database. At the end of March 2015, Australian researchers reported that based on an analysis of the results of deep drilling, the Warbarton Basin, which lies on the border of the South Australia, Northern Territory and Queensland regions, is of shock origin. The cause of this astrobleme is the fall of an asteroid, which split into two fragments about 10 km each before impact. The diameter of the crater itself, the traces of which have already been erased by time, is almost 400 km. The estimated age of the Warbarton Basin is 300–600 million years.
Interestingly, there is another alleged astroblem not far from this place - the Australian impact structure, 600 km in diameter, located between and including two popular attractions of the Northern Territories - the red rock of Uluru and Mount Connor. The age of the structure is about 545 Ma.
Crater Vredefort (South Africa, diameter 300 km)
Crater Vredefort, the remains of the multi-ring structure are clearly visible
The largest officially confirmed astrobleme and one of the rare annular (multi-annular) impact craters on Earth. Plus one of the oldest. It appeared about 2 billion (2023 ± 4 million) years ago due to an impact by an asteroid about 10 km in diameter. The outer diameter of the structure is 300 km, the inner diameter is 160 km. There are three towns inside the crater, and the astroblem itself is named after one of them.
Sudbury Crater (Canada, diameter 250 km)
Sudbury Crater - a well-populated place
Over the 1849 Ma since the Sudbury crater was formed, tectonic processes have distorted its original shape, turning the once round crater into an elliptical one. The culprit for the appearance of the second largest crater on Earth is an asteroid 10-15 km in size. The impact was so strong that the fragments covered an area of 1,600,000 km2, and some fragments flew 800 km away, they are found even in Minnesota. The meteorite literally ripped open the earth's crust, the crater was filled with hot magma, rich in metals - copper, nickel, platinum, gold, palladium. Therefore, today Sudbury is one of the world's largest mining regions. The mineral-rich soil has made the crater and the best agricultural land in Northern Ontario. At the edge of the crater lies Greater Sudbury, a city of 160,000 inhabitants.
Chicxulub crater (Mexico, diameter 180 km)
The approximate dimensions of Chicxulub crater
The celestial body "responsible" for the appearance of the Chicxulub crater is also accused of massacres. A 10-kilometer meteorite that fell 66 million years ago on the Yucatan Peninsula caused a 100-meter tsunami that went deep inland, as well as massive forest fires throughout the Earth. Soot particles lifted into the air blocked the sun and caused a semblance of a nuclear winter. It was this event, according to scientists (by no means all), that led to the massive Cretaceous-Paleogene extinction, the victims of which were, in particular, dinosaurs.
The initial crater depth was 20 km with a diameter of 180 km, and the impact energy reached 100 teratons in TNT equivalent. The largest hydrogen "Tsar Bomba" created in the USSR had a capacity of only 0.00005 teratons. Unfortunately, time has erased the visible traces of Chicxulub crater.
The meteorite that created the Chicxulub crater is responsible for the extinction of the dinosaurs
Some researchers adhere to the multiple impact theory, according to which several meteorites hit the Earth almost simultaneously, which was the cause of the Cretaceous-Paleogene extinction. One of the components may have fallen on the territory of modern Ukraine, creating the Boltysh crater with a diameter of 24 km in the Kirovograd region. The term “at the same time” should be taken on a geological scale, which means with a difference of “only something” in thousands of years.
Akraman crater (Australia, diameter 90 km)
This crater, which became the "basis" for the drying up Lake Akraman in South Australia, was created by a fast (25 km / s) meteorite 4 km in diameter about 580 million years ago. The debris scattered to a distance of 450 km.
Crater Manicouagan (Canada, diameter 85 km)
Crater Manicouagan from the Space Shuttle Columbia
One of the most visible large craters on Earth. Now the eponymous ring lake. It arose 215 million years ago due to the impact of an asteroid about 5 km in diameter. For a long time, the meteorite body that created the crater was believed to be the culprit for the mass extinction in the late Triassic, but recent studies have dropped these charges.
There is a theory that at the same time or almost simultaneously (on a geological scale) with the asteroid that "created" Manikuagan, four more celestial bodies fell to Earth, including the meteorite responsible for the Ukrainian Obolonsky crater near the village of Obolon, Poltava region.
Impact craters very often become lakes. The largest include Lake Karakul in Tajikistan (25 million years old, crater diameter 52 km) and Lake Taihu in China (360-415 million years old, 65 km).
Meteorite craters in Ukraine
Astro problems of Ukraine
Thanks to the stability of the Ukrainian crystal shield, several large astroblems have survived on the territory of Ukraine, moreover, their density is the highest in the world. All craters on the territory of Ukraine are under a layer of organic sediments from 100 to 500 m thick, that is, no signs of astroblems are visible on the Earth's surface.
The largest of the Ukrainian astroblems - Manevicheskaya in the Volyn region, near the village of Krymno, has a diameter of 45 km and arose probably 65 million years ago. The origin of this structure is still in dispute.
The Boltysh crater in the Kirovograd region has a diameter of 24 km and arose 65 million years ago, only 2-5 thousand years earlier than the Chicxulub crater, which confirms the theory of multiple impacts as the cause of the Cretaceous-Paleogene extinction.
All impact craters on the territory of Ukraine are located under a layer of organic sediments with a thickness of 100 to 500 m
Obolonsky crater in the Poltava region appeared 170 million years ago and has a diameter of 20 km. According to some researchers, it originated simultaneously with the craters of Manicouagan (Canada), Rochechouard (France), Saint Martin (Canada) and Red Wing (USA).
Ternovsky crater on the outskirts of Krivoy Rog is 280 million years old and 12 km in diameter. The Ternovsky district of the city and several mining pits are located right in the crater.
The Ilyinets crater in the Vinnytsia region, 7 km in diameter, appeared 400 million years ago, and the Belilovsky crater (6.2 km) in the Zhytomyr region 165 million years ago. Rotmistrovsky crater in the Cherkasy region is 120 million years old and 2.7 km in diameter.
Zelenogayskaya astrobleme in the Kirovograd region consists of two craters. Large, 2.5 km in diameter and smaller, 800 m in diameter. The age of both impact structures is about 80 million years, so it can be assumed that they arose as a result of the impact of two fragments of one celestial body.
Fake astroblemes
Arc Nastapoka at first glance looks like a typical astrobleme
It would seem that with the current level of technology, the presence of a huge number of satellites that are photographing the Earth in all conceivable angles and optical ranges, the search for astroblems should be simplified, but this is not so. Moreover, many cyclic structures that are clearly visible from space, which at first glance cannot be anything other than impact craters, in fact are not such.
Thus, the ideal arc of Nastapoka in Hudson Bay has long been considered the outer wall of a huge, 450 km long crater hidden under water. Investigations in 1976 showed the complete absence of minerals and debris characteristic of impact structures. It is now generally accepted that the arc arose naturally in the process of mountain building.
Cosmonaut Valentin Lebedev compared the Richat structure to a children's pyramid made of multi-colored rings
Another good example of a fake astroblem is the Eye of the Sahara, the Richat ring structure, 50 km in diameter in Mauritania. Rishat was originally thought to be a typical impact crater, but the flat bottom and the absence of impact rocks disprove this idea. According to the current version, the structure owes its shape to the erosion of sedimentary rocks.
Largest stone
The Goba meteorite most resembles an ancient altar
The largest meteorite found on Earth flew to us 80 thousand years ago and was found in 1920, near the Goba West farm in Namibia. According to the name of the area, he was given the name Goba. The celestial stone was found by chance, while plowing the field, no crater remained around it, it is assumed that the fall occurred at a low speed and was not accompanied by a significant release of energy.
The iron meteorite Goba has a size of 2.7 x 2.7 x 0.9 meters and is 84% iron plus 16% nickel. The mass of the "bar", which was never weighed, was estimated in 1920 at 66 tons. As a result of oxidation, the collection of scientific samples and vandalism, the meteorite lost up to 60 tons. Nevertheless, it is still the largest piece of miraculous iron on the planet.
For 95 years, scientists, vandals and the laws of physics "bite off" 6 tons of the Goba meteorite, or 10% of the mass
Crater named foolishness
Bullet hole in Earth - a nuclear crater with a diameter of 1.9 km
The crater on the site of the island of Elugelab, which was once part of the Enewetok Atoll, which in turn belongs to the Marshall Islands, has nothing to do with astroblems, but it illustrates human stupidity in the best possible way.
The funnel with a diameter of 1.9 km and a depth of 50 m remained after the world's first test of a hydrogen bomb on November 1, 1952. The Ivy Mike device, which has no practical military value due to its size, was intended solely for testing a two-stage design in which a nuclear bomb was used as a hydrogen fuse. The explosion power is estimated at 10–12 megatons in TNT equivalent.
Victim # 1
The only documented case of a meteorite hitting a person happened on November 30, 1954 in the United States. A meteorite weighing 3.86 kg, later called Sulakogsky, broke through the roof of the Hodges family house, bounced off a radio set on the table and hit 31-year-old Anne Elizabeth Hodges dozing on the sofa. The Heavenly Stone was slowed down by the Earth's atmosphere and broken ceilings, so that it did not inflict serious injuries on Ann Hodges, the woman escaped with bruises on her side. The next day, a second fragment of the same meteorite, weighing 1.68 kg, was found by Julius K. McKinney, a neighbor of the Hodges family.
Ann Hodges did not capitalize on her popularity, but her neighbor sold the meteorite and repaired his farm
Strategic Defense Initiative
The press, especially the yellow one, often flashes messages about the approach of another asteroid to the Earth, capable of destroying all life. Indeed, modern means of detection, space and ground-based telescopes, are able to detect even a relatively small celestial body. But the detection occurs, as a rule, just a couple of days before the passage of a space object at a minimum distance from the Earth. And often after the closest approach.
Asteroids ranging in size from 10 to 150 m fly past our planet, including at a distance of only 14 thousand km (slightly more than the diameter of the Earth), almost every year. Such objects were discovered in 2005, 2006, 2008, 2009, 2010, 2011 and 2014, but none of them received any significant hazard rating.
Asteroid 2009 VA, 7 m in size, flew by on November 6, 2009, just 14 thousand km from the Earth. Opened it 15 hours before the convergence
Space agencies and private companies in many countries of the world are conducting theoretical research into the destruction or rejection of potentially dangerous asteroids; even the Ukrainian Yuzhmash has a similar drawing project. Various options for the destruction of an uninvited space visitor are considered, up to a scenario close to that shown in the movie epic Armageddon. But, in fact, now earthlings have no protection from threats from space. However, planetary defense is a topic for another big study, perhaps we will return to it later.
In the meantime, NASA plans not to reflect, but on the contrary, to drag a small asteroid closer to Earth to study it and develop technologies for possible mining on asteroids in the distant future. The first stage of the program is scheduled for 2026, more information about the Asteroid Redirect Mission can be found on the NASA website.