How the earth came into being, how the earth came into being

When was the primordial earth born? According to the widely circulated scientific opinion, the primordial Earth was born about 50 million years after the formation of the solar system. But a new view put forward by Jacobson, a scholar at Harvard University in the United States, is that the primitive earth was formed much earlier than that.

Scientists believe that the solar system evolved from a huge nebula, and the material in this nebula was gravitationally gathered into different clumps, the largest clump formed the sun, and the other larger clumps formed planets including the earth. It is believed that the primordial Earth was born when the mass of material that formed the Earth gathered 64% of the Earth's present mass. Jacobson wrote in the American journal Science that they have conducted a new analysis of the process of the decay of hafnium isotopes into tungsten isotopes in the early days of the solar system, and revised scientists' original estimates to estimate that the original Earth was born within 10 million years of the formation of the solar system.

The solar system is thought to have been formed 4,56.7 billion years ago. Jacobson said in the article that in the next 10 million years, the primitive Earth had gathered 64% of the Earth's current mass, and at this time the Earth's "embryo" could be considered to have taken shape. The mark of the end of the process of the formation of the Earth was the birth of the Moon.

This event occurred about 30 million years after the formation of the solar system. Jacobson believes that the Moon may be the product of a collision between a Mars-sized object and the Earth. Resources.

The formation of the earth can be divided into three stages: the formation of the geosphere, the Archean and Proterozoic, and the Phanerozoic. About 4.4 billion years ago, the Earth was covered with warm waters, and it rained day and night.

About 4.2 billion years ago, land appeared on the surface and on the edge of a volcanic crater above sea level, and the continuous invasion of the Earth by asteroids caused the land to collapse into an ocean.

The radius of the Earth's equator is kilometers, the polar radius is kilometers, the average radius is about 6371 kilometers, and the equatorial circumference is about 40075 kilometers. The Earth's surface area is 100 million square kilometers, of which 71% is oceans and 29% is land. The main components of the atmosphere are nitrogen and oxygen, as well as small amounts of carbon dioxide and argon.

The interior of the earth is divided into the core, mantle, and crustal structure, and the surface of the earth has a hydrosphere, atmosphere, and magnetic field. The Earth is the only celestial body in the universe where life is known, and it is home to millions of living beings, including humans.

The systematic scientific study of the origin and evolution of the earth began in the middle of the eighteenth century, and several theories have been put forward to this day. It is now popular to believe that the Earth, as a planet, originated from the primordial solar nebula 4.6 billion years ago.

Like other planets, it has undergone some common physical evolutionary processes such as accretion and collision. At the beginning of the formation of the earth's fetus, the temperature was low and there was no layered structure, but the temperature of the earth gradually increased due to the bombardment of meteorite materials, the heat caused by radioactive decay and the gravitational contraction of the primitive earth. As the temperature rises, the earth's internal materials become more and more plastic, and there is a phenomenon of local melting.

At this time, under the action of gravity, the differentiation of matter begins, the heavier material outside the earth gradually sinks, the lighter material inside the earth gradually rises, and some heavy elements (such as liquid iron) sink to the center of the earth, forming a denser core (the observation of ** waves shows that the outer core of the earth is liquid). The convection of matter was accompanied by large-scale chemical separation, and finally the Earth gradually formed the layers of the crust, mantle, and core that it has today.