Meteorites refer to meteorite remnants falling on the ground, composed of iron, nickel, silicate and other minerals, also known as meteorites. Also refers to meteorites containing more or more stony rocks. A large number of organic compounds, such as ammonia, nucleic acid, fatty acid, pigment and 11 amino acids, have been found in the high carbon meteorites. Therefore, it is believed that the origin of life on the earth is closely related to meteorites. Observations show that there is an asteroid belt between the orbits of the planets of the solar system, Mars and Jupiter. It is the home of meteorites. These asteroids move in their own orbits and collide constantly. Sometimes they are knocked out of their orbits and run toward the Earth. When they enter the atmosphere, they rub against it to give off light and heat. It's meteor. When a meteor enters the atmosphere, it produces high temperature, high pressure and internal imbalance, and then explodes, forming meteorite rain. When an unburned person falls on the earth, it becomes a meteorite. A crater 170 meters deep and 1240 meters in diameter was found in Arizona. In the Antarctic, there is a large crater with a diameter of 300 kilometers. A giant crater with a diameter of more than 1000 kilometers has been found in central the Atlantic.
Iron-nickel meteorites are composed of iron, nickel, silicon, acid and salt minerals, with iron-nickel metal content ranging from 30 to 65. These meteorites account for about 1.2% of the total meteorites, so they have the highest commercial value. This kind of meteorite contains more than 70% iron, followed by silicon, aluminum and nickel. The main minerals are pyramids, nickel-rutile, talc and so on. The minor minerals are pyrite, chromite and graphite. According to the main composition and structural characteristics of the meteorite, it can be divided into olivine iron meteorite (PAL), medium iron meteorite (MES) and palaeopyroxene-lepidolite iron meteorite.