Imagine the Earth, dark and cold, lost in the immense blackness of space night. Could life arise and survive in such an inhospitable world? The answer suggests itself. Of course not.
Although life exists on Earth in the darkest bays and deep gorges, but it was sunlight that was the key to the emergence and prosperity of life on Earth. And our Sun is the star closest to us.
Stars and planets
Although we can imagine the Earth as a lonely, sunless world, but this picture, in fact, will be wrong. Planets, by definition, are cosmic bodies arising from circumstellar dust. That is, planets cannot arise on their own. It is a fact that the life of plants and animals is closely intertwined with the life of stars. We owe life not only to our Sun, but also to those stars that existed a long time ago and no longer exist.
Interesting fact: the iron in your blood, the calcium in your teeth and the nickel change in your pocket - all this was forged in the bowels of distant stars.
When did the first stars appear?
Stars were in the world long before planets and life arose. The first stars were born 12-15 billion years ago, when our Universe was still relatively young. Stars, like people, are born, age, and finally die. During their lifetime, stars absorb elements from the surrounding space and form new elements in their bowels.Before reaching middle age, a young star absorbs hydrogen, from which helium is formed in nuclear fusion reactions. When the supply of hydrogen is exhausted, the star uses helium atoms to synthesize carbon.
Life of the stars
Time is running out. In the bowels of the star more and more heavy elements are formed: oxygen, neon, magnesium, silicon, sulfur. Millions or billions of years after its birth, the star completely runs out of nuclear fuel. Small stars part with life relatively calmly. But giant stars before death usually explode, flashing at the same time so dazzling that they become visible in the afternoon. An explosion of a star throws elements synthesized in its bowels into space. These elements become part of the gas-dust cloud, which moves in interstellar space.
Sometimes, if favorable conditions are formed, from such a cloud consisting of gas and dust, a new star with a planetary system may appear. The sun with its nine planets, including the Earth, was formed precisely from such a cloud. So the elements inside and around you - the iron in your blood, the calcium in your teeth and the nickel change in your pockets - are forged in the bowels of a distant star. Although this distant star provided life on Earth with the necessary chemical elements, the energy that made possible the birth of life on Earth is delivered by our star - the Sun.
The radiation of the young Sun permeated the Earth's atmosphere with its currents.The heat of the Sun formed clouds in the atmosphere, causing electrical atmospheric discharges - lightnings. According to scientists, such lightnings together with ultraviolet rays contributed to the formation of organic molecules, in particular amino acids, building blocks of proteins in the primary ocean. Proteins are the chemical basis of life. How exactly the first living organisms arose, no one still knows. But it is clear that protein molecules played a decisive role in this process.
The life and light of a star
Once, having arisen due to the energy of sunlight, life has developed and continues to exist, using solar energy, like a car that needs the energy of burning gasoline to move. Plants directly use the energy of sunlight photons to synthesize carbohydrates from water and carbon dioxide. People and animals, in turn, breathe oxygen, which is released by plants during photosynthesis (the so-called process of converting water and carbon dioxide into carbohydrates by plants), and eat plants to feed themselves with energy. Animals, in turn, eat other animals. The beginning of all this is laid by the stars.
