Dear readers, thank you for reading my article in your busy schedule, this is an affirmation of my efforts, but also the motivation to continue to create, I would like to extend my most sincere respect to you, I hope to get one of you"Attention"Thank you!Swiss astronomers discovered the first exoplanet in 1995. Since then, the number of identified exoplanets has increased rapidly and now exceeds six thousand, but we can only find them near the solar system. Throughout our galaxy, there are between 100 billion and a trillion stars, according to various estimates, and the visible universe contains more than 200 billion galaxies, many of which are much larger than ours. As a result, there may be a huge number of exoplanets in the universe, many of which are similar in size and chemical composition to Earth, but not all terrestrial planets can support life. Why is this so? Let's figure it out.
We know that the development and existence of life requires at least two conditions: compounds that are the material basis of life, and energy that can continue to support life. Of course, the organism must adapt to the presence of its surroundings. On our planet, it's a water-filled ocean and an atmosphere containing oxygen and nitrogen, as well as temperatures where water remains liquid and organic compounds don't break down in most of the planet. If the basic conditions of survival were very different from those on Earth, then life itself would not be similar to life on Earth. The issue of carbon chauvinism is the subject of another article, which I will try to write in the near future.
In order for life to develop on terrestrial planets, certain celestial physical environments must also be consistent. First of all, the star around which the planet revolves must be similar to the sun, i.e. it must change its size and temperature steadily, and also have a moderate amount of radiation. There should be no variable stars or supernovae near the exoplanet's parent star, and their eruptions produce radiation that can kill living organisms. The orbit of the planet where life is capable must have a low eccentricity, i.e. it must be close to circularity. Only under these conditions can the planet receive light and heat from the parent star evenly. Otherwise, too much temperature change will kill life on Earth.
Also, terrestrial planets should not be very far from the star, and at the same time not too close, i.e. in a region suitable for the existence of life, where the temperature is conducive to the presence of liquid water. In addition, a stellar system should not consist of two or more stars, because in such a system, planets can orbit in very complex, constantly changing curved orbits, which is why they can sometimes overheat or overcool. The rotation period of the planets around the Earth's axis in which life is capable should guarantee its diurnal variation, so that the planet's surface does not overheat during the day and cool at night.
Therefore, if the planet always turns to the star on one side, then half of it will be frozen, the other half will be scorched, and in the thin layer between these two halves, a constant storm will rage, which will not allow the development of life.
The mass of the exoplanet should not be too large or too small. A planet with a mass comparable to the Moon or Mercury will not be able to retain its atmosphere, and there will be no liquid water on it. Conversely, a planet with too much mass will be surrounded by a huge gas shell that will not allow light or heat from the parent star to enter its surface.
The existence of highly developed life is possible only on terrestrial planets orbiting fairly old stars, which can age billions of years. After all, life takes a lot of time to evolve into complex organisms; On Earth, it took nearly 4 billion years. Depending on the gravity of a particular planet, a particular atmosphere, and other conditions, these intelligent beings can have a completely different appearance and perceive the outside world in a completely different way.
At the moment, we are not aware of any planet other than ours that hosts intelligent life or at least some kind of life. But the search continues. NASA astronomers estimate that there are at least 8.8 billion stars in our Milky Way galaxy alone, with Earth-sized planets orbiting their stars within their habitable zone.