The structure of the solar system
Scientists believe that the formation of the solar systembegan about five billion years ago. According to the generally accepted theory, the Earth and the surrounding planets were formed from cosmic dust located in the vicinity of the Sun. According to the assumptions, the dust particles consisted of iron and nickel atoms, as well as silicates. Condensation was also exposed to dust near the dust, which formed carbonaceous organic compounds. Later, nitrogenous substances and hydrocarbons appeared.
The structure of the solar system: hypotheses
A well-known hypothesis of the emergence of our solarsystem is an electromagnetic theory that proceeds from the assumption of scientists that the Sun once had a powerful electromagnetic field, and the nebula surrounding the star consisted of neutrally charged atoms. As a result of radiation and collisions ionization of particles occurred, which fell into traps from magnetic lines of force and were sent after the star. After many years, the Sun began to lose momentum, passing it to a cloud of gas, from which the planets began to form.
However, this theory is unlikely. Essentially, the atoms of light substances should have been ionized closer to the Sun, and heavy metals - further. And the result would be that the nearest to the star of the planet would have to consist of the lightest chemical elements - helium and hydrogen, and distant - from nickel and iron. However, today you can see the opposite picture.
To get rid of the contradiction, was createda new hypothesis, indicating that the Sun began to germinate in the depths of the nebula. The light turned very quickly, and the nebula gradually became flater until it turned into a disk. After a certain period, he acquired acceleration, and the sun - on the contrary, stalled. After this, processes began in the disk, as a result of which the formation of the solar system began.
A well-known hypothesis of the origin of planets is the theory of the appearance of the solar system from the gas-dust cold cloud surrounding the Sun.
The structure of the solar system: planets
Today it is believed that the solar system isfrom the star of the Sun and eight planets. According to physical characteristics, celestial objects can be attributed to two species. One group includes the Earth and planets that have similarity to it - Mars, Venus, Mercury. The second includes such giant planets of the solar system as Neptune, Uranus, Saturn, Jupiter.
The division of the planets is done in threecharacteristics: mass, density and size. The average density of planets belonging to the terrestrial group is five times larger than the same index of giant planets. The structure of the solar system indicates that the objects of the terrestrial group nearest to the Sun have in their composition oxides and heavy compounds of chemical elements: aluminum, magnesium, iron, silicon, and also nonmetals. The low density of giants is due to their structure. They are in a liquid or gaseous state and have hydrogen or helium in the bulk.
However, the structure of the solar system shows thatany of the giant planets by mass exceeds all the celestial objects of the terrestrial group taken together. All giants have extended powerful atmospheres, which consist of molecular hydrogen, and contain ammonia, methane, helium and water. The remaining substances are not more than one percent of their mass. By their composition, the giant planets are similar to other stars, and in the first place - to the Sun.
Atmospheric hydrogen can pass from gaseous form to liquid, and even into solid. The compression of giants is due to the rapidity of their rotation around the axis.
The giant planets have many satellites: Jupiter has more than 60, Uranus has 27, Saturn has 62, and Neptune has 13, as well as orbital rings, which, according to scientists, are from the substance of the collapsed satellites.
Over the giant planets is relativelya small space object - Pluto. It was opened in 1930 and has not been studied well enough. Until 2006, it was believed that our solar system includes nine planets, and Pluto was the last of them. At the present time he is ranked among dwarf planets.
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