This paper takes part in the series essay competition of “great science” of Recordunkown.
Before human beings embarked on the road of science and technology, their observation of the starry sky mainly depended on their eyes. In our eyes’ cognition, the stars in the sky are static and eternal. But with the advent of science and technology and the invention of the astronomical telescope, we have more knowledge of stars.
When human beings walk out of the earth, our knowledge of the universe goes to a higher level. We not only see what the earth looks like, but also know the existence of the solar system and the existence of extrasolar stars. At this time, we understand that stars are not stationary, they are also moving around a larger center of mass, and stars, like life, are limited by their lifespan. According to their mass, the lifespan of stars ranges from tens of millions to tens of billions of years. And our sun is a yellow dwarf, its life span is about 10 billion years, how has gone through 5 billion spring and autumn, another 5 billion years will usher in the final outcome.
Although the ultimate destiny of the sun is to die out, we can’t see the future of the sun, the future of the solar system, after 5 billion years. If time can’t go backwards or run fast ahead of time, can’t we know the future of the solar system? Of course not.
Although we can’t see the final outcome of the solar system with our own eyes, there are countless star systems in the universe, and there are at least 100 billion star systems in the Milky way. Different stellar systems have different lifespan. We can observe and find a stellar system very similar to the solar system. If the stellar system has reached the end, the final evolution scene will occur.
By observing the evolution of this stellar system, we can know the future of the solar system in advance. Through a large number of observations, scientists found a stellar system code named “j0914 + 1914”. This star system is very similar to the solar system. The star is also a yellow dwarf like the sun, and its mass is very close. Therefore, what happens there is of great reference value for human beings to understand the future of the solar system.
“J0914 + 1914” is about 2000 light-years away from the earth. This is a star system that has come to the end. The central star has completed the evolution and turned into a white dwarf. Scientists observed that the white dwarf is absorbing a lot of hydrogen, oxygen, sulfur and other elements. And these elements are ubiquitous on gas giant planets. There are four gas planets in the solar system, so these elements are also abundant.
Why do stars have evolved into white dwarfs and continue to absorb a lot of hydrogen, oxygen, sulfur and other elements? This is an important reference for scientists to understand the future of the solar system. Through the evolution of this galaxy, we can see that after the stars evolved to white dwarfs, they did not calm down, but continued to affect the stellar system.
The reason why the white dwarf “j0914 + 1914” absorbs a lot of oxygen, oxygen, sulfur and other elements is that there is a gas giant planet in the orbit of 10 million kilometers away from the white dwarf, and these elements such as hydrogen, oxygen, sulfur come from this giant planet.
Scientists also found that the giant planet has about 3000 tons of material per second, which will be swallowed by white dwarfs less than half of its size, and will be “baptized” by stellar wind above 28000 degrees Celsius every moment.
The structure of “j0914 + 1914” is very similar to that of the solar system, and our sun will probably evolve into a white dwarf in 5 billion years. Will the same scene be staged in the future of the solar system? If so, what will be the fate of the earth? In this regard, scientists put forward two possible conjectures.
1、 The earth is directly engulfed by the sun. The evolution of the sun to a white dwarf requires several processes. Before the white dwarf, there is a red giant stage. Five billion years later, the hydrogen of the sun is consumed, and the hydrogen nuclear fusion reaction in the center stops. At this time, the first evolution of the sun began, that is, the center continued to collapse, the shell continued to expand outward.
The expansion of the sun will make it bigger and bigger. This is the red giant stage. The evolution of the sun to a red giant will continue to devour the orbits of mercury, Venus, earth and Mars. When the orbit is swallowed up, the earth will probably be smashed by the sun, become dust and disappear in the sky.
2、 The earth is directly thrown to the outermost side of the solar system by the sun’s gravity, thus avoiding the fate of smashing and disappearing. Although this possibility is very small, it is not entirely impossible. We should know that the transition process of the sun to a red giant is a violent activity, which will produce extremely unstable gravitational disturbance to the surrounding orbit.
The strong and disordered gravitational disturbance may make the earth’s motion become very unstable, and the possibility of being thrown out by the sun’s gravity cannot be ruled out. Of course, it is more likely to be swallowed up by the sun.
When the red giant expands to its maximum, the collapse of its interior is completed and it becomes a dense white dwarf. And the shell will collapse into dust. Since then, the evolution from the sun to the white dwarf has been completed. At this time, there are only four gaseous planets left in the solar system. The orbit of the white dwarf will be very close to Jupiter, and it may also absorb a lot of hydrogen, oxygen, gas and dust from Jupiter and Saturn under the action of gravity.
Of course, it will be 5 billion years later. For the survival of human beings, we can’t wait for the earth to come to that day. Because with the continuous reduction of hydrogen in the sun, its early expansion will be earlier, and the temperature will continue to rise, reaching a temperature similar to the surface of Venus. At that time, the liquid water on the surface will continue to evaporate, a lot of vegetation will burn, and the earth will become a fireball.
If human beings want to survive, they will have to leave the earth in advance to live in a new home. Some people may have said that humans could migrate to Mars at that time, but in fact Mars could not become a more ideal new home for humans. We should know that in the later stage of the sun’s evolution to a red giant, it will also devour Mars. Once it evolves into a white dwarf, the solar system will be dead in name.
Therefore, after the end of the solar life, human beings want to find an ideal new home, can only go outside the solar system. If we want to move out of the galaxy, we must first become an interstellar civilization and have the ability of interstellar navigation, otherwise we can only shrink into the solar system. It is not easy to become an interstellar civilization. Although there are billions of years left for the sun to evolve into a red giant under normal circumstances, it is still unknown whether human beings can become an interstellar civilization in such a long time.