We are completely dependent on our star - the Sun. If there were no Sun, there would be no life.

What came before the sun? How did it form?

Five billion years ago, there was neither the Sun nor the nine planets surrounding it.

The atoms that make up our bodies flew in interstellar space in clouds of gas and dust. Scientists think that this gas cloud, consisting mainly of hydrogen, rotated around its axis. The more the cloud collected dust and gas, the more it contracted, that is, decreased.

The force that caused the cloud to shrink is the force of gravity. Inside the cloud, particles are attracted to the particles, connecting together. Gradually, the cloud began to rotate synchronously with all its parts simultaneously.

Interesting fact: the light emitted by the Sun is equal in power to the light of 4 trillion light bulbs.

Sun formation example

To illustrate how this happened, the astronomer William Hartmann proposed a simple experiment. Shake a cup of coffee. The fluid in the cup moves randomly. If you drop a little milk into the cup, the coffee particles will begin to rotate in one direction. Something like that. There was also a cloud in which, little by little, the random movement of particles was replaced by their ordered synchronous rotation, that is, the cloud began to completely rotate in one direction.

Scientists have added a dramatic twist to this story. They believe that when a cloud formed near it, a star exploded. At the same time, powerful flows of matter scattered in different directions. Part of this substance is mixed with the substance of the gas-dust cloud of our solar system. This led to even faster compression of the cloud.

The more the cloud was compressed, the faster it rotated, like a skater, who, while spinning, presses her hands to the body (and also starts to spin faster). The faster the cloud rotated, the more its shape changed. In the center, the cloud became more convex as more matter accumulated there. The peripheral part of the cloud remained flat. Soon the shape of the cloud resembled the shape of a pizza with a ball in the middle. This ball, yes, you guessed it right, there was our child - the Sun. The accumulation of gas in the middle of the "pizza" in size exceeded the modern size of the entire solar system. Scientists call the newborn Sun a protostar.

How did the sun turn from a gas ball into a star?

This happened very, very slowly, for thousands and thousands of years, while the protostar and the cloud surrounding it continued to shrink under the influence of gravitational forces. The atoms that make up the cloud collide, generating heat. The temperature of the cloud grew, especially in a denser center, where the frequency of atom collisions was higher. The gas in the protostar began to glow. In the bowels of the emerging Sun, the temperature gradually rose to millions of degrees.

At such inconceivably high temperatures and equally high pressure, something new began to happen with squeezed and pressed to each other atoms. Hydrogen atoms began to combine with each other, forming helium atoms. Each time hydrogen was converted to helium, a small amount of energy was released - heat and light. Since this process took place everywhere in the core of the sun, this energy flooded the entire solar system with light. The sun turned on like a giant electric lamp. From that moment, the Sun became a living star, the same as we see in the night sky.

Nuclear fusion of the sun

The sun produces energy during a process called nuclear fusion. Nuclear fusion is a controlled explosion in the center of the sun, where temperatures range from 15 million to 22 million degrees Celsius. Every second in the bowels of the Sun, 4 million tons of hydrogen are converted to helium.The power of the light flux that is emitted is equal to the power of 4 trillion light bulbs.

Interesting fact: when the sun was young, it was 20 times larger and 100 times brighter than now.

What will happen to the sun next?

It is worth recalling that the hydrogen reserves in the sun are limited. Over time, the composition of our luminary changes. If at the beginning of its history the Sun consisted of 75 percent hydrogen and 25 percent helium, now the hydrogen content has dropped to 35 percent. As you guessed, there comes a moment when hydrogen disappears in the bowels of the star. Like any fuel, in the end, hydrogen is exhausted. There is nowhere for the sun to get new hydrogen. The core of the star now consists of helium. The core is surrounded by a thin hydrogen shell. The hydrogen of the shell continues to turn into helium, but the star has already entered the order of decline.

When will the sun cease to shine?

Like humans, stars are born, age and die. At its 4.6 billion years old, the Sun is a middle-aged star. Scientists believe that the sun remains to live about 5-6 billion years. As you age, hydrogen will gradually disappear from the solar core. The nuclear fusion process will move closer to the surface layers. But sooner or later, the process of synthesis of helium nuclei from the nuclei of hydrogen atoms will stop. The helium core will slightly decrease in size and a new process will begin - helium nuclear fusion.

Helium, which was synthesized billions of years ago, will begin to shrink, helium atoms will come together until, finally, carbon atoms are synthesized from them. The sun will continue to shine. But it will become colder and larger in size. The surface temperature of the Sun from 5,500 degrees Celsius, as it is now, will decrease to 3,200 degrees Celsius. A larger and colder Sun will emit red light. Such aging stars we call red giants.

Interesting: in the future, the Sun will increase in volume and absorb Mercury and Venus.

The sun will begin to swell until it absorbs Mercury and Venus. When the surface of the Sun approaches the Earth, the temperature on it will rise significantly. The oceans boil away. And the Earth will become a rocky, dry, lifeless planet, like the current Mercury. Then people, apparently, will have to look for a more suitable habitat.

When all helium is exhausted, nuclear fusion involving carbon atoms will begin. But nuclear fusion cannot last forever. The sun will gradually lose from the scattering in space the remnants of its gas shell and only the hot solar core will remain. From the red giant, the Sun will turn into a white dwarf, wrinkling, possibly to the size of the Earth. A white dwarf is a very dense cosmic body, a teaspoon of white dwarf substance weighs about a ton. Millions of years later, the white dwarf, the former Sun, will cool down and turn into a bunch of dark cold ash. The sun will become a black dwarf.

Stars that are larger than the Sun end their life journeys in a more bizarre way. After the reserves of hydrogen and helium are exhausted, the processes of oxygen synthesis from the nuclei of carbon atoms begin. When the core of the star becomes purely oxygen, the synthesis of neon from the nuclei of oxygen begins. Other elements are synthesized from neon. Finally, nuclei of iron atoms are synthesized from elements such as silicon. Over time, the iron core of the star shrinks, and here a grandiose explosion can occur. An exploded star, called a supernova, spills all its contents into outer space.

Black hole and stars

Even more massive stars can shrink into a black hole. In a black hole, the force of gravity is so great that even a ray of light cannot come off its surface. A black hole is like a whirlpool sucking in any matter that comes in its way. In this case, the black hole grows.Some scientists consider black holes to be gates to other Universes, or black holes can be used to travel through our Universe, so to speak, as short dashes. So although the stars are dying, some of them are being reborn as new, strange and wonderful space objects.