What is the solar system? This is our common home. What does it consist of? How and when was it formed? It is important for everyone to know more about the corner of the Galaxy in which we live.
From largest to smallest
Lesson "The solar system" should start with the fact that the latter is part of a vast and boundless universe. The scale of its 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 its modest size and stable temperature, life was able to originate in its system.
Rise
Modern theories of the emergence of the solar system are inextricably linked with hypotheses about the evolution of the universe. Its origin is still a mystery. There are only various mathematicalmodels. 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 does 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 limit of its atmosphere will be just at the distance of the Earth's orbit. And if after such a huge period of time humanity still exists, then for people it will become a catastrophe of a truly universal scale. But all this is in the distant future. What is the current situation?
Solar system bodies
So, first of all, this is, of course, our star. Since ancient times, people have given her a name and called the Sun. Ninety-nine percent of the mass of the entire system is concentrated in it. And only one falls on the planets, their satellites, meteorites, asteroids, comets and Kuiper belt bodies. So what is the solar system? This is the Sun and everything that revolves around it. But first things first.
Sun
As mentioned above, the star is the center of our system. Its dimensions are amazing. The sun is 330,000 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 greater, and there, thanks to the colossal pressure, nuclear reactions begin. Here from hydrogenhelium is produced.
Then, the energy released as a result of this is transferred to the outer layers with the help of convection and dissipates in outer space. According to scientists, our Sun is now 75% hydrogen, and about 25% helium, the remaining elements are no more than 1%. First of all, this suggests that the Sun is in full bloom, because there is still a lot of fuel. The typical 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. At its center is a massive core, followed by radiant energy transfer zones, convection, photosphere and chromosphere. Prominences often appear on the latter. Sunspots are areas on the surface of a star where temperatures are noticeably cooler, which is why they appear darker. Our luminary rotates around its axis with a period of twenty-five Earth days. It is hardly an exaggeration to say that the entire solar system depends on the state of this star. Photolaboratories for studying the processes on it have been created even in orbit.
Mercury
This is the first cosmic body that we will meet, moving away from the Sun. And as a consequence of its proximity, it is very hot on the surface and there is practically no atmosphere. It belongs to the so-called terrestrial planets. Their common characteristics are: 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, Mercury is practically deprived of the atmosphere -blown away by the solar wind. Recall that the Earth is protected from it by a strong magnetic field and distance. But despite this, the gaseous shell on Mercury can still be detected, it consists of metal ions that evaporate from the surface of the planet. There are (in small amounts) oxygen, nitrogen and inert gases.
Around the Sun, Mercury moves in an elongated orbit. Its orbital period is 88 Earth days. But it takes almost 59 days for the planet to rotate around its axis. Largely due to this, there is a large temperature difference on Mercury: from minus 1830 to plus 4270 Celsius.
The surface of the planet is covered with craters, low mountains and valleys. There are also traces of the compression of Mercury (due to the 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 terrestrial planet from the Sun. It is much larger than Mercury, but slightly smaller than the Earth in both mass and diameter. There are no satellites. But there is a dense atmosphere, which almost completely hides the surface of Venus from our eyes. Thanks to it, the temperature on the surface is much higher than on Mercury: the average values reach +4750 Celsius, without serious daily fluctuations. Another feature of the atmosphere is the strongest winds at a height of several kilometers (up to one hundred and fifty meters per second), real hurricanes. What causes them is still unclear. Composedthe atmosphere is ninety-six percent carbon dioxide. Oxygen and water vapor are negligible. Thanks to the 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 uplands. There are two major continents. There are many impact craters.
Earth
We will not dwell on our planet in detail, since it is still 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 a planet in the solar system, which is second only to 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 - 150,000,000 kilometers - is taken as an astronomical unit. Let's also say that the Earth is a planet in the solar system, which has a single satellite of significant size, and let's move on.
Mars
And here we have the red planet - the dream of all science fiction writers and a celestial body that people never stop thinking about. A spacecraft is currently operating on the surface of Mars. And in ten years they are already going to send a manned spacecraft there. Why are people so interested in Mars? Yes, because according to 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 firstthe planet from which man will begin exploration of the solar system.
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 is six hundred and eighty-seven Earth days long. 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. The highest mountain in the solar system, Mount Olympus, is on the Red Planet. Its height is about 12 kilometers. Mars also has two small moons, 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. It can detect 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 something that 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 made of various metals, so that in the distant future they can be used in industry.
Planets-giants
Unlike 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 terrestrial planets. Saturn is famous for its rings, which are actually made up of many small objects. The density of these planets is much less than Earth's. The substance of Saturn is generally lighter than water. Almost all giants have a solid core. Their atmospheres are made up of hydrogen, helium, ammonia, methane and a small amount of other gases. Moreover, the composition of Jupiter and Saturn is in many ways similar to the composition of our Sun.
Therefore, it is not surprising that they are considered unformed stars. They just didn't have enough mass.
Uranus and Neptune can only be considered true gas giants, since they have a powerful atmosphere. However, apparently, they still have a hard surface. But where Jupiter begins is difficult to say. It is believed that the core of the largest planet in the solar system consists of metallic hydrogen. Almost all giants radiate their own energy (heat), and in quantities greater than they receive from the Sun. All have rings and many satellites. Hurricanes of unprecedented power rage 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 thisstatus), as well as Makemake, Eris, Huamea comparable to it in mass and size. These are the so-called new planets of the solar system. And 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. A photo report from these places, it is quite possible that we will soon receive 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 have been discovered.
