The sun, in the rays of which we all love to luxuriate on a warm summer day, is not only the basis of all life on our planet, but also a kind of thermonuclear delayed-action bomb that will destroy the Earth in the future.
There is no point in describing the importance of this star for the planet: suffice it to say that without the Sun, no life on Earth would simply exist. Our star was formed about 4.5 billion years ago by the compression of the gas-dust cloud of molecular hydrogen by the gravitational forces. All the increasing pressure and temperature eventually triggered a thermonuclear reaction in the nucleus of the star that has been formed, which continues to this day.
It’s interesting: the color of the Sun is white, and not yellow at all, as we see it in the sky.
The fuel for the thermonuclear reaction inside the core of the Sun is hydrogen, which, according to approximate calculations, will last for another 6.5 billion years. Given that the stars of the sunlike type “live” on average about 10 billion years, our star was still relatively young and did not exceed even the middle of its life path, so for the fate of their children and even children of children of your children’s children (and then practically indefinitely ) You do not have to worry.
But in fact, the problems for humanity will begin earlier than in 6.5 billion years. Of course, it is rather difficult to imagine that the mankind living in constant hostility and threatening to destroy each other will exist even after a few million years (and not to forget the external dangers – meteorites, supernova explosions), but if this happens, people can live on planet in the very distant future, the end of them will be painful and terrible.
When a thermonuclear reaction occurs in the solar core, the hydrogen turns into helium. Already for billions of years every second the Sun processes 4.26 million tons of matter, gradually changing the composition of its core. As the hydrogen is consumed, the Sun’s core shrinks even more and, accordingly, becomes brighter and hotter. According to rough estimates, brightness and temperature increase by 10% every billion years. The figure is not so large, but for a surprisingly balanced inhabited zone in which our planet is located, even a one percent change in the parameters of the Sun can be fatal for a developed life. Computer modeling has shown that in 1 billion years life on our planet for highly developed creatures will become impossible because of the high surface temperature and the greenhouse effect caused by the evaporation of large volumes of water. On average, the surface temperature will increase by 40-50%, and people, if they exist at that time, will have to hide deep under the ground or water in special bunkers.
It’s interesting: at the beginning of its existence the Sun was 30-40% less bright than now.
It is likely that at that time, only deep-sea marine life and thermophilic bacteria, which can survive at extremely high temperatures, will feel comfortable. Perhaps in the absence of competition they can evolve and evolve to sentient beings, but all this is only fantasy, while dry scientific facts tell us that in 3.5 billion years from today, when the Sun will spend 3/4 of hydrogen in its core, life on Earth will be completely impossible even for the simplest life – all the seas and oceans will dry out, and the surface will warm up so much that it will resemble today’s Venus. The planet will become completely lifeless, but the real apocalypse will happen later. After about 6 billion years, the ever decreasing and denser core of the star will reach such a high temperature that it will be enough to “start” the process of hydrogen burning not only in the nucleus, but also in the outer layers, which will result in an increase in the volume of the Sun, compared with the current one. The sun will become much brighter and hotter, all energy released during the fusion of hydrogen will be directed to the outer shell, which will cause its growth, while the core itself will consist of condensed helium. Our star will turn into a red giant.
Perhaps that’s how the surface of the Earth will look like in a few billion years
The core of the star will continue to thicken, and at a certain point its temperature will be enough to start the helium burning reaction. For a few hundred million years, the star will find stability and even slightly diminish in size, but it will be just a calm before the storm. After 7.7 billion years from today, helium inside the nucleus will end, converting to carbon in the combustion process. The core of the Sun will again begin to decrease, and the outer shell will begin to grow many times. According to modern ideas, the Sun will be 256 times more than now!