After the birth of the earth, the moon was born about 65438+ billion years ago, that is to say, the moon was born 4.5 billion years ago. Of course, this hypothesis is based on the impact to explain the birth of the moon. According to current human cognition, as early as 4.5 billion years ago, the earth collided with a planet similar to Mars. At that time, most of the lava and crustal fragments formed by these two planets were splashed into space. When the moon was born, it was only about 22,300 kilometers away from the earth.
In other words, the newly born moon is very close to the earth. You know, at present, the distance between the moon and our earth is about 400 thousand kilometers. The main reason may be that the moon is away from our earth at a speed of 3 cm per year. According to physicists, in the hundreds of millions of years since the moon was single, its rotation speed was very fast. At that time, a day on earth was equivalent to six hours today. That's four times faster than it is now. In addition, as early as 4.3 billion years ago, the young earth suffered a large number of asteroid impacts, which triggered the continuous eruption of volcanic lava on the earth's surface. It is no exaggeration that the temperature of the whole earth's surface has reached more than 4000 degrees Celsius.
Over time, about 3.8 billion years ago, the impact frequency of asteroids began to decrease. At this time, the temperature of the earth's surface began to decrease gradually, and the magma began to consolidate, gradually forming a small land mass, just like the unevenness of the moon's surface. Scientists are bounded by the earth's crust. Before the crust appeared, it was called astronomical period, and after the crust appeared, it was called geological period. During the asteroid impact and volcanic eruption, a new substance appeared on the earth, that is water. With more and more rain on the earth, the most primitive ocean was born about 3.5 billion years ago.
Since then, the prelude to the evolution of life on earth has been opened. The surface temperature of the earth during this period was about 85 degrees, which was much higher than the average temperature today. However, microorganisms began to appear in the primitive ocean during this period. With the increasing number of microorganisms, they began to multiply and evolve in the primitive ocean. Time came about 750 million years ago, when the continents on the earth split. At this time, several continents split off on the earth, which took about 65.438+0.2 billion years. The polar ice sheet extends to the equator and even forms a snowball earth.
Until one day 540 million years ago, long-term accumulated plate movements promoted volcanic eruption and broke the ice. Billions of tons of carbon dioxide were injected into the atmosphere, and the atmosphere began to warm. At this time, with the arrival of CAMBRIAN, the life on the whole earth has undergone an explosive reproduction process, and the marine fauna has grown in large numbers. Until about 420 million years ago, primitive algae evolved into naked ferns. Except for moss, all terrestrial higher organisms originated from naked ferns. 370 million years ago, the first fleshfin fish finally set foot on the mainland, and its fins evolved into limbs. After 6.5438+0.5 million years' purification, quadrupeds appeared constantly, and these clan animals began to look for food on land, which would mean that amphibians on the earth began to land.
With more and more oxygen on the earth, animals on the whole land began to evolve on a large scale, so dragonflies as big as eagles appeared on the earth, as well as giant red deer and giant centipedes. At this time, a lizard laid eggs on land for the first time, which means that creatures left the ocean and explored further land. 200 million years ago, another mass extinction happened on the earth. It turned out that the main cause of this mass extinction came from the large-scale explosion of Siberian dark rocks, which made a large number of plants wither and the whole earth surface was corroded by acid rain. At this time, the surface temperature of the earth also rose, and a large number of species could not survive during this period, and about 95% were extinct.
About 65 million years ago, an asteroid fragment with a diameter of about 10 km hit the earth's surface again, and the impact low point was in Yucatan Peninsula in the Gulf of Mexico. Asteroid impact directly triggered earthquakes and tsunamis, as well as volcanic eruptions. A generation of dominant dinosaurs disappeared from the earth, and a large number of animals and plants disappeared at the same time. This period of history is called the late Cretaceous mass extinction event. Of course, although this period caused the extinction of dinosaurs and other large animals, it also gave mammals a chance to successfully avoid the threat of dinosaurs.
By 46 million years ago, the earth's surface temperature gradually stabilized at around 24 degrees Celsius, and the earth's rotation speed slowed down to around 24 hours. At this time, the Indian Ocean plate collided with the Eurasian plate, and the Himalayas were formed. Without natural enemies, mammals began to evolve More than 4 million years ago, due to climate change, apes originally living in East Africa had to migrate to other places. In this process, apes learned to walk upright. 654.38+0.8 million years ago, Homo erectus appeared. Human civilization officially appeared in the records of earth civilization. It can be seen that in the 4.6 billion years of life of the earth, human beings did not appear until 4 million years ago. To some extent, the appearance of human beings is really only a moment, which also shows that we humans are really too small in the history of the whole earth.