When did the earth have life? When did life begin to appear on Earth?

Life existed about 4 billion years ago.

4.6 billion years ago, the Earth originated from the primordial solar nebula. After these 4.6 billion years of continuous evolution, the Earth has gradually formed the blue planet it is today. It is one of the eight planets of the solar system, which not only rotates from west to east, but also orbits the sun.

According to scientific records, the evolution of the earth is divided into the following three stages.

1. The first stage of the Earth's evolution is the formation of the Earth's sphere, which is about 4600-4200 mA (million years). According to scientists, the Earth is the primordial solar nebula, which was formed as a hot fireball composed of magma at the beginning of its formation. Over time, the temperature of the Earth's surface continues to drop, and a solid core gradually evolves.

The denser material gradually moved towards the center of the earth, and the less dense material gradually moved towards the surface, which formed a predominantly rocky earth.

2. The second evolutionary stage of the Archean and Proterozoic periods is the Archean and Proterozoic periods, which date from 4200 to 543 ma. The earth began to continuously release its own energy outward, constantly spewing out high-temperature magma, releasing water vapor, carbon dioxide and other gases, and then there was an early primitive atmosphere. As the water vapor in the primordial atmosphere increases, more and more water vapor accumulates together to form small raindrops, which in turn fall to the earth's surface, thus forming the primordial ocean.

3. The third evolutionary stage of the Phanerozoic period is the Phanerozoic period, which has a time limit from 543 ma to the present. This period of time is relatively short, but during this time period, the development of life on the earth is very rapid, the geological evolution is very rapid, and the geological processes have become rich and colorful. More advanced organisms gradually evolved on Earth.

These creatures already have clear shells and clear bones, new species have been added to the earth, and primitive creatures have begun to mutate or evolve.

Dear readers, do you understand?

Life on Earth originated between 4.6 billion and 3.5 billion years ago. To date, the oldest fossils of organisms have been found from Western Australia, about 3.5 billion years ago. These fossils were similar to the current spirulina and were primitive life, ranging from a few microns to dozens of microns in size.

There are many conjectures and hypotheses about the origin of life, and there are many controversies, which is a major problem that modern natural science is trying to solve. At present, the theory of chemical origin is generally accepted by the academic community, which is based on the theory of "Origin of Species" and Miller's Shiwang imitation. With the deepening of understanding and the discovery of various evidences, people will have more in-depth research on the question of the origin of life.

When did the earth begin to have life as follows:

1. Answer: Life appeared about 1 billion years after the formation of the Earth.

2. Basic introduction: The earth is one of the eight planets in the solar system, the third in order from near to far from the sun, and it is also the terrestrial planet with the largest diameter, mass and density in the solar system, with a distance of 100 million kilometers from the sun. The Earth rotates from west to east while revolving around the Sun.

It's now 4,04.6 billion years old, and it has a natural satellite called the Moon, which forms a celestial system, the Earth-Moon system. 4.6 billion years ago, the Earth originated from the primordial solar nebula.

3. English expression: earth

4. The proportion of sea and land: 71% is ocean, and 29% is land.

5. Basic form: The radius of the Earth's equator is kilometers, the polar radius is kilometers, the average radius is about 6371 kilometers, and the circumference of the equator is about 40076 kilometers.

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The Earth is speculated to have survived for 4.6 billion years, but how long will it live?

Scientists believe that if the Earth is allowed to move freely, it may exist forever, but if other external factors interfere with it, the Earth may have an end of life.

The external factor is the sun in the first place, because it is the closest planet to the earth and can have a destiny on the right earth That is to say, all the energy and power on the earth come from the sun, and once the sun has three long and two short, it is bound to affect the earth. Before the 30s of this century, people always thought that the sun would one day burn out, turn from white to orange and then to red, and finally become a dark star that was silent, but its brilliant life. In the 30s, when physicists learned the mystery of the sun's light, the situation was very different.

It turns out that the Sun's energy comes from its thermonuclear reactions, and the Sun's lifetime will pass through the gravitational contraction phase, the main-sequence star phase, the red giant phase, and the compact star phase. The main sequence phase is the period of stability of the Sun. This phase will last for 10 billion years.

At present, the sun is only halfway through and is in middle age. Once the Sun reaches the red giant stage, then the end of the Earth is coming. Of course, this is billions of years away.

Some scientists believe that the Sun may have a brother, a companion star of the Sun, which orbits the Sun day and night, and turns away from the Sun every 26 million years.

The nearest place to come"Make waves"Its strong gravitational pull will cause a large disturbance of many comets, and 1 billion comets will be on a rampage in the solar system, and the Earth and other planets will become these comets"Target"。If the mass of the comet that collides with the Earth is large enough, the consequences are unimaginable: the extinction of light organisms and the upheaval of ecology; Heavy landslides and earth cracks, the earth"Broken bones"。

However, this solar companion star, which could bring misfortune to Earth, has not been discovered, although many scientists believe it exists.

The earth has a history of 4.6 billion years since its formation. The earliest fossils of organisms with cellular structures have been found so far from about 3.5 billion years ago.

Scientists estimate that life on Earth should have been born earlier than that, possibly about 3.8 billion years ago.

That is, life on Earth appeared only a few hundred million years after the formation of the Earth, when the Earth's crust had just stabilized and the primordial oceans had just formed.