In most cases, falling meteorites will not cause any harm. But sometimes it will fall into the house, smash through the roof and ceiling, and hurt people and animals. Such natural disasters are indeed unexpected, but sometimes they seem strange.
1880, a small meteorite landed on the back of an American donkey. 19 1 1 year, a dog in Egypt was hit by a meteorite and died.
There is an interesting and rare event: 1928, a 0.2-gram celestial stone hit a little girl, and the meteorite grazed her face and burned her clothes.
In archaeological excavations, there are also amazing discoveries. 1892 When excavating in Argentina, a skeleton was found 6 meters underground. This is the remains of an extinct large LEPIDOPTERA lazy beast killed by meteorites millions of years ago. That meteorite is next to the skeleton.
Scientists believe that about 25,000 years ago, an iron meteorite with a diameter of about 50 meters and a weight of 500,000 tons fell into the crater of Cape Bahrain.
At the beginning of August, 1972, Dr. Rogoff of NASA released a terrible disaster forecast to the United States. He said, "1on the afternoon of August, 1972 10, there will be a big meteorite with destructive power comparable to the atomic bomb that fell in Hiroshima, Japan, to attack the western United States!" In those days, residents in the western United States were in a state of panic.
At the scheduled time, I saw a dazzling fireball quickly cut through the blue sky, passing Utah, Idaho, Montana and British Columbia in Canada in the western United States. A whole hour has passed, and the trace left by this meteorite is still clear. Thousands of Americans and Canadians witnessed this rare sight with their own eyes, and many astronomy enthusiasts successfully took photos.
This meteorite didn't fall on people's heads, it can only be said to be a fluke. At that time, the meteorite entered the atmosphere tangentially at an altitude of 58 kilometers at a speed of 15 kilometers per second. Just because it is fast enough, it breaks away from the gravity of the earth and returns to the universe. According to the observation records, Dr. Rogoff concluded that the meteorite weighed thousands of tons, equivalent to the specific gravity of iron, with a diameter of 4 meters and a flight speed of 50 times the speed of sound. Considering its weight and speed, its energy is equivalent to 20,000 tons of TNT, and its destructive power is comparable to that of the atomic bombs dropped by the United States in Hiroshima and Nagasaki.
"There are few opportunities for giant meteorites to visit the Earth, but meteorites around 1000 tons may attack the Earth every 10 or 20 years." Dr Rogoff warned. If the people in the 1972 incident were lucky, some people before or after that were not so lucky.
1954165438+1On the afternoon of October 30th, Mrs. hodges was taking a nap on the sofa in Alabama, USA. Suddenly, with a whistle, an object broke through the roof, punched a hole in the sofa and scratched Mrs. hodges's abdomen. It was a meteorite that hurt Mrs. hodges.
The first meteorite crash occurred on the morning of September 29th, 1938. A meteorite weighing 2 kilograms landed on the roof of a garage in Illinois, USA, and then passed through the roof. Fortunately, no one was injured.
19921On the evening of October 9, a bright fireball passed through most parts of Kentucky, North Carolina, Maryland and New Jersey. After a chondrite penetrated the body of a Chevrolet car in Pixar, new york, it lay firmly in a small pit formed by it. When the owner found this stone weighing 12kg, it was still hot and smelled of sulfur. Because this incident is very rare, this ordinary meteorite sold for $69,000, and the price of the damaged car was much higher than that of the new car.
Looking back, there are also some examples of near misses.
1847 July 14 The meteorite attack was very famous and took place in a small village called Blanau in Bohemia, Czech Republic. A meteorite weighing 20 kilograms flew into the room of three sleeping children from the roof and smashed the bed. Incredibly, the three children are safe and sound.
/kloc-one day in 0/890, in Kansas, a farmer was daydreaming under a carriage. Suddenly there was a deafening noise, and the dust was flying, and the vegetation around the farmer was swept away. It turned out that a meteorite weighing 5 kg was shot down in an open space 18 meters away from where he was lying.
If a meteorite falls on someone's canopy, it will die. However, the probability of this happening is extremely low, only once every few hundred years. According to ancient records, China, Italian, French, Indian and other countries have been hit by meteorites. In China, in AD 6 16, dozens of people were killed by meteorites. 15 1 1 year, Milan, Italy, someone was hit by a meteorite. 1790, a French farmer died in a meteorite attack; In India 1825 and 1878, one person was killed by a meteorite.
With the development of navigation and aviation, meteorites hit ships and planes in flight.
1907 and 1920, meteorites were observed in the Atlantic Ocean near sailboats. Later, the event that the ship sank because of the meteorite impact finally happened. 1908 In February, an American cargo ship named Eccleps was on its way back to San Francisco from Newcastle, Australia. Suddenly, a meteorite hit the ship and made a loud noise. The mast of the ship broke in two at once. The meteorite hit a big hole on the deck, then penetrated the bottom of the ship and fell into the Pacific Ocean. Fortunately, this meteorite caused no casualties, but in the next four days, the crew had to pump water desperately because of the influx of seawater from the cave, but the hull was still sinking. The captain had to give an order to abandon the ship and all the crew were transferred to the lifeboat. They were 900 kilometers away from Hawaii at that time. If they hadn't been rescued by passing ships, they would have been buried in Wang Yang.
1930, the Greek cargo ship Sarkiris, which was sailing in the Mediterranean, suffered even greater misfortune. A meteorite hit the middle of the ship, split it in two and sank in an instant. 1957 65438+1On the night of October 29th, the former Soviet ship Izmir was sailing back to Odessa from Kolkata. Suddenly a meteor appeared in the dark sky, and the fire flashed. A small meteorite weighing only17g hit the mast and landed on the deck. Some experts speculate that some ships that suddenly disappeared at sea may have been hit by meteorites and sank. 1887, a Japanese warship registered in France disappeared shortly after leaving Singapore on the way back, which shocked the whole of Japan. Later, some scholars thought that the culprit of missing warships might be meteorites.
The Bermuda Triangle in the west of the North Atlantic is a place that makes people feel terrible. It is famous for the mysterious disappearance of at least 35 ships and planes here for many years, and at least 1000 people have gone here and never returned. Books, movies and TV plays describing these mysterious disappearances emerge one after another. However, those who want to solve the mystery of Bermuda Triangle are still empty-handed and have found nothing.
Some experts believe that some ships killed in this area were caused by meteorites. In space navigation, if you encounter the impact of meteoroids, it will seriously endanger the safety of instruments and astronauts.
In addition to natural meteorites, we sometimes encounter artificial celestial stones. Near the northwest of Slovakia, the tractor driver Neck was working in the field when a sharp whistle drowned out the rumble of the tractor and a piece of metal fell into the tractor's track. Although the surface of this metal has melted in the atmosphere, traces of processing can still be seen. Chemical analysis shows that this is an alloy. According to the identification of scholars, this stone from heaven is a fragment of a satellite.
Although these "uninvited guests" have caused all kinds of shocks and injuries to mankind, every visitor from the universe-meteorite-has its important scientific value. You know, meteorites are samples of materials that make up other celestial bodies. By analyzing the composition and structure of meteorites, we can know the composition of other celestial bodies. Our analysis of meteorites shows that no unknown elements have been found so far. This shows that the material contained in the meteorite itself is the material that constitutes the earth and other planets in the solar system.
With the help of these stones, we can further understand the formation and development of planets in the solar system. Many scientists believe that meteorites are fragments left by scattered planets, and the mineral composition of meteorites is the same as that on earth, which can confirm this. However, some people believe that some of these meteorites are the result of volcanic eruptions of planets such as Jupiter in the solar system. Others think it is formed by a cloud of gas and dust, which once enveloped the sun at some time long ago. 3. "Origin" and "Quality" of Meteorites
What are these unexpected guests, meteorites? Where did they come from and how did they come to earth? Until a few years ago, people confused meteors with meteorites and thought that there was some cosmic dust around the sun. When they are close to the earth, they will be attracted and fall into the atmosphere, rubbing against the atmosphere and releasing heat and light. This is a meteor. Those that didn't burn out fell to the surface of the earth and became meteorites. However, in recent years, people have made it clear that meteors and meteorites are two different things. Meteors are separated from comets, and meteorites mostly belong to asteroids.
The event that proved that meteorites were asteroids occurred in 1947, but meteorites were cited as asteroids in recent years. That year, a meteorite landed in the Schott Mountains in Siberia, the former Soviet Union.
1947 February 12 in the early morning 10: 30, a huge meteorite fell in the west hote mountains north of Vladivostok, just 40 years after the Tunguska Big Bang. About 100 people witnessed a fireball as big as a full moon shining brightly against the blue sky, sweeping across the sky from north to south. When it flies, it will produce sparks. Soon people heard a deafening explosion. The earth trembled, and the meteorite landed and raised a huge column of smoke, rising to an altitude of 30 kilometers. The roofs of scattered houses near the landing site collapsed and the glass was shattered. The scientific investigation team sent to the scene found countless potholes on the hillside of the West Hote Mountains, with the largest diameter of 20 meters and the smallest diameter below 1 meter. There are more than 200 pits in the area of 1.6 square kilometers. Scientists speculate that this is an iron meteorite, weighing 35 tons, which was shattered by four explosions during the friction with the earth's atmosphere.
Shihot Mountain is close to the Sea of Japan, and this area is inaccessible, so there are no casualties. If this iron meteorite flies 500 kilometers south, it will hit Hokkaido, Japan; If this iron meteorite had landed 15 minutes earlier, it would have landed in Hokkaido, Japan. If so, the loss will be serious!
According to eyewitness testimony, the direction and angle of iron meteorites, scientists have figured out the orbit of iron meteorites in space before they hit the earth. The orbit of the Schott iron meteorite is a slender ellipse, which is located between Mars and Jupiter when it is farthest from the sun. When approaching the sun, the orbit is inside the earth and intersects with the earth's orbit. It was captured by the earth when it approached the earth.
1959 On the night of April 7th, a meteorite happened to fall while taking pictures of celestial bodies at the igor andreev Observatory in the former Czechoslovakia. According to the falling trajectory of this meteorite, scientists once again calculated that its previous orbit was as long and thin as an asteroid. This observation once again confirmed that meteorites are asteroids. However, in order to eliminate accidental factors, in 1964, some scientists installed the 16 automatic photography device named "Grassland Net" in the vast grassland area in the central United States, and continuously took photos of the ground and the air. If a meteorite came, it could immediately capture its flight trajectory and speed.
Meteorites are not something that can be photographed casually. For six years, the negatives of 16 automatic photographic equipment were all empty. Until the night of1970 65438+1October 3, a meteorite fell in Oklahoma, and the impact noise caused by it could be clearly heard for thousands of square kilometers. This meteorite was photographed by four automatic cameras. Its orbit, like the two meteorites mentioned above, is a slender ellipse similar to an asteroid. After this observation, there is almost no objection to the explanation that meteorites originated from asteroids.
As for the "quality" of meteorites, there are still many kinds of meteorites, which can be roughly divided into stone meteorites, similar to rocks on the earth, called iron meteorites made of iron, and those in between are called stone iron meteorites.
Of the 100 meteorites that landed on the earth's surface, almost 90 were stone meteorites, 5-6 were iron meteorites, and the rest were stone iron meteorites. But due to weathering, people often see iron meteorites.