What is a meteorite?

Meteorite, also known as "meteorite", is a kind of unburned stone, iron or a mixture of stone and iron, which is quickly scattered by cosmic meteors or dust fragments from the original orbit outside the earth to the surface of the earth or other planets. Because meteorites are foreign bodies from outer space, they need to be identified by instruments, and the naked eye only plays an auxiliary role. Most meteorites come from the asteroid belt between Mars and Jupiter, and a few come from the moon and Mars. Meteorites can be roughly divided into stone meteorites, iron meteorites and mixed meteorites. The average density of meteorites is between 3 and 3.5, and the main component is silicate. Meteorites have a density of 7.5 ~ 8.0 and are mainly composed of iron and nickel. The composition of stone and iron is between the two, and the density is between 5.5 and 6.0. Meteorites have different shapes. The largest meteorite is Jilin 1 meteorite, weighing 1770 kg, and the largest meteorite is Namibian Goba meteorite, weighing about 60 tons. China Stone Crown is a "silver camel" found in Qinghe, Xinjiang, weighing about 28 tons. More than 40,000 meteorite samples of various styles have been collected all over the world. It can be roughly divided into three categories: stone meteorites (mainly silicates), iron meteorites (iron-nickel alloys) and stone-iron meteorites (mixtures of iron and silicates).

Meteorite refers to the meteorite residue falling to the ground, which is composed of minerals such as iron, nickel and silicate, also known as meteorite. Also refers to meteorites containing more or all rocks. A large number of organic substances such as ammonia, nucleic acids, fatty acids, pigments and 1 1 amino acids were also found in meteorites with high carbon content. Therefore, people think that the origin of life on earth has a considerable relationship with meteorites.

It is found that there is an asteroid belt between the orbits of planets, Mars and Jupiter in the solar system, which is the hometown of meteorites. These asteroids run in their own orbits, constantly colliding, and sometimes being knocked out of orbit and heading for the earth. When they enter the atmosphere, they will rub against them and give off light and heat. This is a meteor. Meteors enter the atmosphere, producing high temperature, high pressure and internal imbalance, and then explode to form meteorite shower. The unburned material falls to the earth and becomes a meteorite. A crater with a depth of170m and a diameter of1240m was discovered in Arizona, USA. There is also a big pit with a diameter of 300 kilometers in Antarctica. A giant crater with a diameter over 1000 km was found in the middle of the Atlantic Ocean.