The earth has been born for 4.6 billion years, the earth was born to the present has experienced countless ups and downs, but the evolution and development of life has not stopped, and then the birth of human beings has made the earth a civilized planet, the earth has upgraded, with the rapid progress of human science and technology, the exploration of the universe is also deepening, and human understanding of the universe has slowly increased.
Since exploring the universe, human beings have not given up looking for the existence of extraterrestrial life, but decades have passed, we still have not found any extraterrestrial life, which can also show that life is rare in the universe, and intelligent life is very rare. If there is no life in the universe, no intelligent civilization, only the earth has life and civilization, it is also very unrealistic, the universe is too big, there will definitely be life or even civilization in a certain corner of the universe, but relative to the vast universe, life is still relatively very little, intelligent civilization is as rare as a giant panda.
Many people may say that life in the universe is so rare to see, why is the earth so fortunate to have a wealth of life species, and more human civilization, what is so special about the earth? Let's take a look at why life was born on Earth, which is definitely not an ordinary planet.
First of all, from the earth itself, there is a strong magnetic field, so that you can strongly block the invasion of cosmic rays on the earth, 71% of the earth is the ocean, the birth of life is inseparable from water, especially the birth of intelligent life is inseparable from water, water is the source of life evolution. The earth also has a thick atmosphere, which can block cosmic rays, block the burning of the earth by sunlight, let the earth protect a suitable temperature, and the thick atmosphere can also effectively block some small meteorites, so that they will burn out before hitting the earth.
Secondly, let's talk about the environment outside the earth, the earth is one of the eight planets of the solar system, and the solar system is a single star system, only one star sun, so the solar system itself is a very stable environment, and in the universe of double galaxies, three galaxies and other galaxies are also many, such galaxies Stability is relatively poor, the more stable the galaxy is easier to give birth to a living planet.
The stable environment of the solar system has created conditions for the earth, and the earth and the sun are at a moderate distance, in the habitable zone, and the solar system is a very special galaxy, where is it special? Because there is a huge planet Jupiter, Jupiter is larger than the other seven planets combined, its huge volume and mass, natural gravity is also very strong, it is right in front of the Earth, so that the asteroids of the solar system, comets and some other wandering celestial bodies, will be attracted by the massive Jupiter, so that the Earth will be spared from being hit by these wandering objects.
Although there is Jupiter in front of the earth, but the earth is still 65 million years old by a small line of impact, resulting in the extinction of dinosaurs, while 80% of the life on the earth also with the extinction of dinosaurs, it can be seen that the impact of asteroids will bring mass extinction to the earth, fortunately, the probability of such a thing is extremely small, since the earth suffered an asteroid impact 65 million years ago, until now, it has not been hit by an asteroid.
Many may say that the solar system without asteroids naturally can not hit the earth, if you think so, the solar system has an asteroid belt, where the asteroid will often deviate from the orbit into a wandering celestial body, the reason why it did not hit the earth, is by the gravitational influence of Jupiter crashed into Jupiter, perhaps the asteroid's orbit will be greatly changed, will not hit the earth, if there is no Jupiter, the probability of the earth being hit by the asteroid is at least 1000 times greater than now.
In addition to Jupiter's protection of the earth, we should also thank Mars, the moon, Mars has a lot of craters on it, and Mars in front of the earth can also attract some meteorites for the earth, the moon is the earth's natural satellite, it has more craters on it, which shows that the moon has often suffered from meteorite impacts, if there is no moon, a considerable part of these meteorites will crash into the earth, it can be seen that the earth in the solar system is heavily protected, in order to evolve safely, in order to give birth to life, Humanity was born and became a civilized planet.
Finally, let's talk about the position of the solar system in the Milky Way, to ask where the environment of the Milky Way is more complex, the more intense, it must be close to the center of the Milky Way, scientists can often observe some drastic changes in the central belt of the Milky Way through astronomical telescopes, either super-planetary explosions, or major impact events, or black holes swallowing surrounding celestial bodies, etc., it can be seen that the Milky Way is destroying and disaster every day, and the universe is not as peaceful as everyone thinks.
The position of the solar system is in a very remote position in the Milky Way, this position has few celestial bodies, few stars, the environment is very stable, we rarely find some drastic celestial changes around the solar system, the solar system and the solar system close to the solar system are very stable, so that no major cosmic disaster will descend on the solar system, the earth can also develop safely, and human beings can develop safely and stably.
But there is no eternal security and stability in the universe, human beings must develop science and technology rapidly, only the rapid progress of human civilization, into the real interstellar civilization, we have a broader space for development, at that time even if there is a small line to hit the earth, we can also use high-tech weapons to eliminate it, if the solar system encounters a disaster from the universe, human beings can not cope with the time, we can also take the spaceship to leave the earth in time, to the universe to find another planet suitable for human survival, Only then can human civilization continue indefinitely.