The atmosphere is the guarantee for the survival of a planet. Under the protection of the atmosphere, the organisms on the surface of the planet can live happily. One of the conditions for the birth of a planet is the atmosphere. Without the atmosphere, the planet would be exposed to cosmic rays and life would be gone.
Most of the eight planets in the solar system have atmospheres in varying degrees. Generally, the gravitation of these planets with atmospheres is large enough. Jupiter, Saturn, Uranus and Neptune, because of their great mass, absorb a lot of gas and become gaseous planets. This shows that gravitation does play a major role. Although the mass of the earth is not as large as theirs, it also has a strong influence It’s very attractive, so it can absorb the atmosphere.
Gravity is just one aspect. Small mass does not necessarily mean there is no atmosphere. For example, Pluto’s gravity is very small, but it has a thin atmosphere. Mercury, which has a much larger mass, has no atmosphere. This also shows from the side that gravity is not the determinant of whether a planet has an atmosphere. What is the decisive factor?
The earth is a living planet. It is different from many other planets in that the earth has a strong magnetic field. In other words, the interior of the earth is like a huge magnet. The existence of a magnetic field may be the key to the existence of an atmosphere. Mars also has a thin atmosphere. According to the analysis of scientists, Mars had a thick atmosphere like the earth in a very early period. The reason is that Mars also has a magnetic field. This is why scientists attach great importance to Mars. Because of the magnetic field, human migration is possible in the future.
Why does a living planet have to have a magnetic field? Can’t you survive without a magnetic field and an atmosphere? Now let’s talk about the importance of the lower magnetic field.
Take our solar system as an example. The sun is a huge star in the solar system. All stars have to revolve around it. When the powerful nuclear fusion inside the sun releases energy from time to time, flares will occur on the surface of the sun. When such flares erupt, a large amount of solar wind will blow out from the inside of the sun. The solar wind belongs to the stellar wind, and the solar wind is charged hydrogen ion, which is very important At 350 to 1000 kilometers per second, this speed is 10000 times faster than the fastest wind on earth.
When this kind of hydrogen ion wind hits the planet’s atmosphere at a very fast speed, it will transfer the kinetic energy brought by the speed to the atmospheric molecules, push the atmospheric molecules to escape speed, so as to escape the binding effect of the planet’s gravity. After a long time, the atmosphere will be blown away, and mercury has almost no atmosphere. That’s the reason.
Once the atmosphere is blown away by these solar winds, do you think the planet can survive? This is how Mars became what it is now. In the early days of Mars, like the earth, there was water, magnetic field, atmosphere, and maybe civilization. But later, the magnetic field of Mars may have changed dramatically, unable to resist the solar wind, and the atmosphere of Mars was gradually blown away, so Mars became more and more desolate.
How does the magnetic field resist the solar wind? The solar wind is a group of positively charged hydrogen ions, that is, the wind with charge. If only the charged ones are charged, they will be interfered by the magnetic field. When the solar wind comes to 70000 kilometers away from the earth, it will encounter the magnetic lines of the earth’s magnetic field. This range extends from 70000 kilometers to 700 kilometers above the earth’s surface. During the process of the solar wind station moving towards the earth, it will be controlled by the magnetic lines of the earth and move along the magnetic lines of the earth, so these hydrogen ion winds begin to deviate from the direction of the earth To the north and south poles of the earth, or with the gravitational line of the magnetic field. The aurora phenomenon we see at the earth’s poles and nearby areas is actually the scene when the solar wind is captured by the earth’s magnetic lines of force.
In this way, we can find that most of the solar wind can’t touch the earth’s atmosphere. Of course, it can’t blow away the atmospheric molecules, and the atmosphere will be safe. The earth’s magnetic field protects our atmosphere in this way. It can be said that it is the “invisible shield” of the earth.
Therefore, we should protect the earth well, and we should not let the earth’s environment follow Mars’s footsteps, especially in the depths of the earth’s core. Although the earth’s science and technology can not drill to the earth’s core at present, it will be able to do so sooner or later in the future. If, at that time, for the sake of resources, human beings go to mine the metal iron in the center of the earth, the earth’s magnetic field may be destroyed. Perhaps the early Mars was destroyed in this way. When the Martian civilization developed to be able to enter the center of the earth, some people wanted to mine the iron and other metals deep in the center of the earth, but they did not expect to destroy the Martian magnetic environment. Mars had no magnetic shield, and the sun would be destroyed The wind drove straight in, and the atmosphere was slowly blown out.