The two craters in the southwest are both between 200 and 300 kilometers in diameter, and the distance between them is only 140 kilometers. These two craters may be the product of the impact of the same asteroid 200 million years ago. This may be the largest asteroid that has hit the earth so far.

Crater in Arizona, USA

Arizona Crater, Nevada, USA. This crater was the result of an iron meteorite with a diameter of about 30-50 meters hitting the ground 50,000 years ago. This meteor weighs about 500,000 kilograms, its speed reaches 20 kilometers per second, and its explosive power is equivalent to 20 million kilograms of TNT, which is even bigger than the atomic bomb dropped by the United States in Hiroshima, Japan 1000 times. The explosion produced a large pit on the ground, with a diameter of about 1245 m and an average depth of 180 m. It is said that there can be 20 football fields in the pit, and the surrounding stands can accommodate more than 2 million spectators.

Yucatan crater, Mexico

Chicxulub crater, Yucatan Peninsula, Mexico, diameter 198km. The perpetrator was a small celestial body with a diameter of 10 to 13 km 65 million years ago. The crater is buried under limestone with a thickness of 1 100 m. It was first discovered by oil exploration workers, and later the space shuttle Endeavour confirmed its existence through remote sensing technology.

Tunguras crater, Russia

There are traces of meteorites in Tunguska, Siberia, Russia. 1On June 30th, 908, witnesses saw a fireball streaking across the sky from south to north and disappearing beyond the horizon. Then a flame rose on the horizon and there was a huge explosion. A few days after the explosion, the sky in Tunguska was covered with gloomy orange, and white nights appeared continuously in large areas. Investigators believe that this is an explosion caused by a meteorite hitting Siberia. It is speculated that this asteroid or comet fragment with a diameter of less than 60 meters broke into the atmosphere and exploded 8 kilometers from the ground. 1947, 12 In February, a big explosion similar to Tungulas occurred in the Russian Far East city of Xihot, and more than 0/00 craters were found, and more than 8,000 pieces of ferronickel meteorites were collected, with a total weight of more than 28 tons.

Meteorites and craters in China

1490, meteorite shower took the lives of tens of thousands of people in China. In Duolun, Inner Mongolia, about 200 kilometers north of Beijing, which borders Hebei and Mongolia, there is a very large pit-like terrain, which is likely to be a crater. This pit has a concentric annular "ridge" with an outer ring diameter of 170 km and an inner ring diameter of 70 km, which was formed about10.3 billion years ago. 1On March 8th, 976, a large-scale meteorite shower occurred in the suburb of Jilin City, Jilin Province, China. The falling area has a diameter of more than 70 kilometers and an area of 400 to 500 square kilometers. * * * More than 100 meteorites were collected, with a total weight of 26 16 kg, of which "Jilin 1" meteorites weighed 1 kg.

Gosbluff

The Australian explorer Goss discovered Goss Cliff in 1873. The first people who visited this crater were aborigines living in the Australian desert, and the campsite of the crater left traces of their activities that year. Like most similar craters, Goss Cliff also has geological cracks radiating from the center to the surrounding areas. According to scientists' research on the formation of the pit, it is confirmed that it was formed by the impact from space10.3 billion years ago. The impact object is extremely fast, but its density is relatively low, so it is speculated that it is a comet (composed of solid carbon dioxide, ice and dust) rather than an asteroid meteorite.

The original crater is about 20 kilometers in diameter, and the crater surrounded by Goss Cliff is only 4 kilometers in diameter. That's the crater in the center, and the periphery has been eroded for hundreds of millions of years. There are two hard sandstone cliffs at the outer edge of the pit, which are180m higher than the plain ground. It was also formed in the collision of comets. Underground detection shows that the same rock stratum is 2 kilometers underground, so you can imagine how strong the impact force was that year.

South Pole

Some scientists have suggested that there is a crater with a diameter of 240 kilometers and a depth of 800 meters under the ice near the pole of the Antarctic continent. Six or seven hundred thousand years ago, a small celestial body hit the earth from here, and the direction of the earth axis and the rotation speed of the earth changed accordingly. Researchers found and recovered 23,000 meteorite samples on the Antarctic ice sheet.

Karakul crater in Tajikistan

This crater on the Pamirs near the Afghan border was formed about 65438+ 1 100 million years ago, with a diameter of 45 kilometers.

The crater of Qingshui Lake in Canada

These are twin craters, which were formed 290 million years ago and may have been caused by the simultaneous impact of two asteroids. The west of the crater is 32 kilometers in diameter and the east is 22 kilometers in diameter.

Forrest Gump Crater, Maniku, Canada

There is an obvious annular lake covered with ice in the crater. This crater has a diameter of 100 km and was formed 2 10/00,000 years ago.

Wolf Creek Crater, Australia

Located in the center of the northern desert. With a diameter of 875 meters, it was formed 300,000 years ago and is a relatively young crater. The height of the pit edge is 25m, and the depth of the pit center is 50m. There are still residues of iron meteorite oxidation in the crater, as well as glass objects formed by the melting of sand grains at high temperature.

Spider pit

Located in the west of Australia, the earthquake rupture cone found in the center of this crater defines the age of the spider crater to some extent, although this value is still very uncertain. NASA believes that the impact event that formed this crater occurred in Neoproterozoic about 900 million to 600 million years ago, when the earth was experiencing a severe freezing period and was called "Snowball Earth" by geologists.

Olonga Crater in Lake Chad, Africa

Diameter 17km, which was formed 200 million years ago.

Rotkam crater in Namibia

It is 2.5 kilometers in diameter and was formed 5 million years ago.

Crater in Germany

With a history of/kloc-0.5 million years ago, it is already a lush farmland.

Fordford Crater in South Africa

It has a diameter of more than 30,000 meters and is about 2 billion years old.

Dinosaur crater

Dinosaurs are the largest terrestrial vertebrates that have ever appeared on the earth. The mystery of their sudden extinction seems to have been slowly solved. The reason may be that an asteroid hit Mexico's Yucatan Peninsula 65 million years ago. The recent computer simulation in the United States also illustrates this point. It was not until 12 years ago that this huge crater was discovered. From 200 1 to 65438+February, the geographical research center in Potsdam, Germany started the research in this field. This celestial body may have hit a crack several kilometers deep on the earth's surface with the impact force equivalent to 654.38+000 billion atomic bombs. The fragments of the impact scattered one after another, causing strong earthquakes, tsunamis, floods and fires. A large amount of dust and gas produced by this collision mixed into the atmosphere, which covered the sky and made the climate abnormal. First the fire, then the ice age, and then the unbearable heat. This ecological disaster led to the extinction of animals and plants, including dinosaurs.