What is the solar system? This is our common home. What does it consist of? How and when did it form? It is important for everyone to know more about the corner of the Galaxy in which we live.
From bigger to smaller
The Solar System lesson is worth starting with the fact that the latter is part of a vast and limitless Universe. The scale of her human mind is not able to comprehend. The stronger our telescopes become, the deeper we look into space, the more stars and galaxies we see there. According to modern concepts, the Universe has a certain structure. And it consists of galaxies and their clusters. The place where the solar system is located is the Milky Way galaxy. It consists of one hundred billion stars, many of which are similar to the Sun. Our luminary is a rather ordinary yellow dwarf. But largely thanks to the modest size and stable temperature in his system, life was born.
Occurrence
Modern theories of the appearance of the solar system are inextricably linked with hypotheses about the evolution of the universe. Its appearance is still a mystery. There are only various mathematical models. According to the most common of them, our Universe arose seventeen billion years ago as a result of the Big Bang. It is believed that our star is 4.7 billion years old. The solar system is about the same age. How long did she have to live? In a billion years, the Sun will move into the next cycle of its development and turn into a red giant. According to the calculations of most scientists, the upper boundary of its atmosphere will be located just at the distance of the Earth’s orbit. And if, after such a huge period of time, mankind will still exist, then for people it will become a catastrophe of a truly universal scale. But all this in the distant future. What is the current situation?
Bodies of the solar system
So, first of all, this, of course, is our star. People from ancient times gave her a name and called the Sun. Ninety-nine percent of the mass of all systems is concentrated in it. And only one falls on the planets, their satellites, meteorites, asteroids, comets and bodies of the Kuiper belt. So what is the solar system? This is the Sun and all that revolves around it. But first things first.
The sun
As mentioned above, a star is the center of our system. Its dimensions are amazing. The sun is three hundred thirty thousand times heavier than the Earth! And its diameter exceeds the earth one hundred and nine times. The average density of the Sun's matter is only 1.4 times higher than the density of water. But this should not be misleading. Indeed, in the central regions of the star, the density is one hundred and fifty times higher; there, thanks to the colossal pressure, nuclear reactions begin. Here helium is formed from hydrogen.
Then, the energy released as a result of this is transferred by convection to the outer layers and dissipated in outer space. According to scientists, our Sun now consists of hydrogen for seventy-five percent, and about 25% of helium, the remaining elements no more than 1%. First of all, this suggests that the Sun is in full bloom, because there is still a lot of fuel. Typically, the lifetime for a star of this class (yellow dwarf) is ten billion years. It is impossible not to say a few words about the structure of the Sun. In the center of it is a massive core, followed by zones of radiant energy transfer, convection, photosphere and chromosphere. Prominences often arise on the latter. Sunspots are areas on the surface of a star where the temperature is noticeably lower, which is why they look darker. Our luminary rotates on its axis with a period of twenty-five earthly days. It is unlikely to be an exaggeration to say that the entire solar system depends on the state of this star. Photo labs for studying processes on it are created even in orbit.
Mercury
This is the first cosmic body that we will meet, moving away from the Sun. And as a result of its proximity, the surface is very hot and almost no atmosphere. It belongs to the so-called planets of the earth group. Their general characteristics: rather high density, the presence of a gas-water atmosphere, a small number of satellites, the presence of a core, mantle and crust. However, as mentioned above, the atmosphere of Mercury is almost deprived - it blows off the solar wind. Recall that the Earth is protected from it by a strong magnetic field and distance. But despite this, the gas shell on Mercury can still be detected, it consists of metal ions that evaporate from the surface of the planet. There is (in small quantities) oxygen, nitrogen and inert gases.
Around the Sun, Mercury moves in an elongated orbit. The circulation period is 88 earth days. But to turn around the axis of the planet it takes almost 59 days. Largely due to this, there is a big temperature difference on Mercury: from minus 183 0 to plus 427 0 Celsius.
The surface of the planet is covered with craters, low mountains and valleys. There are also traces of compression of Mercury (due to cooling of the metal core) - in the form of extended ledges). Scientists suggest the presence of water ice in some shaded areas of the planet.
Venus
The second Earth-type planet from the Sun. It is much larger in size than Mercury, but slightly smaller than the Earth both in mass and in diameter. There are no satellites. But there is a dense atmosphere that almost completely hides the surface of Venus from our eyes . Thanks to it, the temperature on the surface is much higher than that on Mercury: average values reach +475 0 Celsius, without serious daily drops. Another feature of the atmosphere is the strongest winds at an altitude of several kilometers (up to one hundred and fifty meters per second), real hurricanes. What causes them is not yet clear. The atmosphere is ninety-six percent carbon dioxide. Oxygen and water vapor are negligible. Thanks to flights to the planet of several spacecraft, scientists were able to compile a fairly detailed map of Venus. The surface of the planet is divided into plains and elevations. Two major continents can be distinguished. There are many impact craters.
Land
We will not dwell on our planet in detail, since it is nevertheless the most studied and known to the reader. But what is the solar system without the Earth? .. I must say that our house is still fraught with many mysteries. In addition, the Earth is the planet of the solar system, which is second only to the gas giants in mass, and the only one that has a water shell. The period of revolution around the star is 365 days, and the distance to it - 150 million kilometers - is taken as an astronomical unit. We also say that the Earth is the planet of the solar system, which has a significant single satellite, and we will go further.
Mars
And here we have the red planet - the dream of all science fiction writers and a celestial body that people never stop to think about. Now a spacecraft is operating on the surface of Mars. And ten years later they are planning to send a manned ship there. Why are people so interested in Mars? Yes, because under the conditions this planet is closest to the Earth. Astronomers of the past generally assumed that there are water channels and plant life on Mars. The search for the latter, by the way, continues to this day. Perhaps this will be the first planet with which man begins to study the solar system.
By mass, Mars is half the size of Earth. Its atmosphere is quite rarefied and consists mainly of carbon dioxide. The average surface temperature is minus 60 degrees Celsius. True, in some areas of the equator, it can rise to zero. The Martian year lasts six hundred eighty-seven earthly days. And since the planet’s orbit is quite elongated, the seasons on it are different in duration. The poles of the planet are covered with thin caps of ice. The surface of Mars is rich in craters and hills. On the Red Planet is the highest mountain in the solar system - Olympus. Its height is approximately 12 kilometers. And Mars has two small satellites - Phobos and Deimos.
Asteroid belt
It is located between the orbits of Mars and Jupiter. In fact, this is a very vast and interesting area. In it you can find a million different objects, mostly small - up to several hundred meters. But there are also giants, such as Ceres (diameter - 950 km), Vesta or Pallas. At first they were also considered asteroids, but in 2006 they were recognized as dwarf planets, like Pluto. All these objects were formed at the time of the formation of the solar system. Perhaps all asteroids are what never became a planet due to the strong influence of the rapidly forming Jupiter. There are many different types and families of asteroids. Among them are those consisting of various metals, so that in the distant future they can be used in industry.
Giant planets
In contrast to such a cosmic body as the Earth, the planets of the solar system located behind the asteroid belt have a much larger mass. And first of all, it is, of course, Jupiter and Saturn. These giants have many satellites, some of which generally resemble the size of the planet of the earth group. Saturn is famous for its rings, which are actually made up of many small objects. The density of these planets is much less than the earth. Saturn's substance is generally lighter than water. Almost all giants have a solid core. Their atmosphere consists of hydrogen, helium, ammonia, methane and a small amount of other gases. Moreover, the composition of Jupiter and Saturn is in many respects similar to the composition of our Sun.
Therefore, it is not surprising that they are considered unformed stars. They simply did not have enough mass.
The true gas giants Uranus and Neptune can only be considered conditionally, since they have a powerful atmosphere. However, apparently, they still have a solid surface. But where it starts at Jupiter is hard to say. It is believed that the core of the largest planet in the solar system consists of metallic hydrogen. Almost all giants emit their own energy (heat), and in quantities greater than those received from the Sun. All have rings and many satellites. Hurricanes of unprecedented power are raging in their atmospheres (the farther the planet is from the Sun, the stronger).
Kuiper Belt
Quite already the backyard of the solar system. Here is the former planet Pluto (in 2006 it was deprived of this status), as well as Makemake, Eris, and Huamea, comparable in mass and size to it. These are the so-called new planets of the solar system. And also thousands, if not millions, of other smaller bodies. Apparently, the Kuiper belt does not extend beyond 100 astronomical units. According to scientists, short-period comets come from here. The Oort Cloud ends the solar system. It is quite possible that we will soon receive a photo report from these places from the New Horizons spacecraft.
So, in short, we showed what the solar system is and what elements it consists of. Now it includes five large planets, our star, and many smaller objects. However, modern science is actively developing. And probably tomorrow we will be able to find out that new planets of the solar system are discovered.