The earth is the third closest planet to the sun and the home of our species. Although Earth is a common planet in our solar system, it is unique in many ways.
For example, it's the only planet in the solar system with most of its area covered by water, and the only one known to have life.
In the 21st century, scientists confirmed the age of the Earth again. They believe that the earth was born much later than the solar system, with a span of about 150 million years.
Previously, scientists calculated the age of the solar system to be 5.568 billion years ago. The Earth is about 3 billion to 4.5 billion years older than the solar system.
British researchers reported in the magazine of "Celestial Biology" that if there were no asteroid impacts such as possible changes in the environment, the earth was suitable for humans to live for about 1.75 billion years. However, artificial climate change may shorten this time.
In the entire solar system, there is only life on the earth. There are many planets in the galaxy, but the planets that have bred life have not appeared. So first of all, let's take a look at the major basic conditions of the earth that can breed life.
The distance between the earth and the sun is moderate. Throughout the birth of all life, the distance from the sun is definitely the primary condition.
Because if the earth is too close to the sun, the high temperature will steam the liquid water of the earth, making the earth a rock planet with no water. Once the earth is too far away from the sun, the low temperature will make the earth "ice hockey" unparalleled.
The modest distance means that only one part of 2.2 billion of the sun's rays reaches the Earth. Sunlight is a very important factor in the development of life. It's important that the sun's radiation has been shining steadily on the Earth for billions of years.
Above we talk about the temperature of the earth, which is very suitable for the emergence of liquid water. The surface of the earth covers a lot of water, and they are like a large swimming pool, making the earth colorful.
More than 70%of the earth's surface was covered by water. Water is the source of life. Almost all the life on the earth is bred from the sea, so it is very important to have liquid water on the planet.
The earth has an absolutely safe position. This means that the earth is in a very safe trajectory in the solar system. Each of the eight major planets in the solar system has its independent running trajectory, and it will not easily collide with the planet, so it is relatively safe.
The earth has a moderate-thickness of the atmosphere. The atmosphere is a veritable "protective cover". It can resist the impact of small meteorites and prevent the surface from being harmed. At the same time, it can also resist the invasion of surface creatures from harmful rays from the universe.
More importantly, the atmosphere is also the "insulation layer" of the earth. It locks the heat emitted by the sun during the day, so that the earth will not be too cold when the sun does not have the sun at night, providing a suitable temperature for the birth of life.
