A series of incredible coincidences led to the fact that somewhere in the infinite cosmic ocean, in an unremarkable galaxy, near the normal star life began. It’s a little weird, but it was the energy of the Sun allowed me to write this article, and you should read it. The sun is the symbol of life itself. No wonder our ancestors worshipped him, giving star divine power. But if life on Earth will someday disappear, what will happen to the Sun? Modern science and technology has allowed us not only to look into the past of the Universe, but also to predict future events. In this article, you will learn, will absorb the Sun Venus, mercury and the Earth.
The life and death of the Sun
Let’s start with the fact that the Sun is an ordinary star. She illuminates the Solar system with light and warmth, setting the daily cycles of sleep and wakefulness in all living organisms on our planet. But the Sun will not always be so. There will come a time when our own star dies, and the whole Solar system will turn into a very unpleasant place. It is important to understand that all physical processes occurring in the Sun greatly influence the physics of planets (at least closest to the star).
The average distance from the earth to the Sun is 150 million kilometers. Light overcomes this distance in 8 minutes. For comparison, the next nearest star Proxima Centauri is from us at a distance of 4 light years.
Astronomers klassificeret the Sun as a young star with high metal content. This means that the Sun formed from remnants of older stars. Current age of our sun, the researchers estimate approximately 4.6 billion years, which means that the star has lived about half her life, since her growing up phase, the main sequence lasts 10 billion years. After this period comes the next stage of its evolution. As soon as the Sun consumes its reserves of hydrogen fuel, it becomes hotter and its luminosity increases. By the time when the Sun will celebrate its 5,6 billionth birthday, it will be 11 times brighter than it is today.
Researchers believe that by this time on our planet will happen a radical change of life, or it completely disappear. Actually, some scientists believe that human civilization will die long before the Sun expands into a red giant. Read more about it I talked in a previous article.
Red giants are stars, in nuclei in which the combustion of hydrogen ceased. For this reason, the kernel is no longer the energy is released and it begins to shrink and heat up under the action of gravitational forces. Since during compression the temperature of the core rises, it ignites the hydrogen in the core surrounding the thin layer.
Turning yellow dwarf to red giant is one of the most unusual transformations, known to modern science: the helium core of the Sun, the size of a giant planet, is compressed and heats up. In response to this, the Sun will grow 100 times. The expanded light will swallow mercury and Venus and possibly the Earth. Astronomers watching from another Solar system would classify this bloated version of our Sun as a red giant.
It should be noted that with the transformation of the Sun into a red giant will inevitably lead to new kinds of thermonuclear reactions, in which the core of a star more compressed and heats up. When the core temperature reaches 100 million degrees Celsius, helium will ignite and begin to fuse together into carbon and oxygen. This leads to the fact that the Sun will be slightly reduced, but after a while – and for the next 100 million years, it will again begin to expand. In the last phase of life will happen cyclic, soft release of gas astronomers call a planetary nebula.
Three and a half billion years later, the brightness of the Sun will increase by 40%. By this time, the researchers believe that our planet will turn into something resembling a modern Venus: the water from the surface of the Earth will completely disappear, which will lead to the final destruction of all terrestrial organisms (assuming that they were able to adapt to changing conditions billions of years ago). After another 6.4 billion years the Sun will begin to expand relatively fast, while maintaining a constant luminosity. In the end, after 7 billion years from the present time our native star turn in subgiant star, the core of which was over all the hydrogen fuel.