The scheme of the solar system. Dimensions of the solar system

The solar system is a tiny structure on the scale of the universe. At the same time, its dimensions for a person are truly grandiose: each of us, living on the fifth largest planet, can hardly even estimate the scale of the Earth. Modest dimensions of our house, perhaps, are felt only when you look at it from the porthole of the spacecraft. A similar feeling arises during the viewing of the images of the Hubble telescope: The universe is huge and the solar system occupies only a small part of it. However, we can study and study it precisely, using the obtained data for interpreting the phenomena of deep space.

The Universal Coordinates

The location of the solar system, scientists determine by indirect signs, because we can not observe the structure of the galaxy from the side. Our piece of the universe is located in one of the spiral arms of the Milky Way. The Orion hose, named so because it passes near the same name constellation, is considered a branch of one of the main galactic sleeves. The sun is located closer to the edge of the disk than to its center: the distance to the latter is about 26 thousand light years.

Scientists suggest that the location of our piece of the universe has one advantage over the others. In general, the Galaxy of the Solar System, the Milky Way, possesses stars, which, due to the peculiarities of their movement and interaction with other objects, are then immersed in spiral arms, then emerge from them. However, there is a small area called the corotation circle, where the speed of stars and spiral arms coincides. The space bodies placed here are not affected by the violent processes characteristic of the sleeves. To the corotation circle is the Sun with the planets. Such a situation is considered one of the conditions that contributed to the emergence of life on Earth.

The scheme of the solar system

The central body of any planetary community is a star. The name of the solar system gives an exhaustive answer to the question about which earth the Earth and its neighbors are moving around. The sun is a star of the third generation, located in the middle of its life cycle. It has been shining for more than 4.5 billion years. Approximately the same number of planets around it.

The scheme of the solar system today includes eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune (about where Pluto went, just below). They are conditionally divided into two groups: planets of the terrestrial type and gas giants.

"Relatives"

The first type of planets, as the name implies, includes Earth. In addition to her belong to Mercury, Venus and Mars. All of them have a set of similar characteristics. The terrestrial planets consist mainly of silicates and metals. They are distinguished by high density. They all have a similar structure: an iron core with an admixture of nickel is wrapped with a silicate mantle, the top layer is a bark that includes silicon compounds and incompatible elements. This structure is broken only in Mercury. The smallest and nearest planet to the Sun does not have a crust: it is destroyed by meteoric bombardments.

The largest planet of the group is the Earth, followed by Venus, followed by Mars. There is a certain order of the solar system: the planets of the terrestrial group make up its internal part and are separated from the gas giants by the asteroid belt.

Major planets

Among the gas giants are Jupiter, Saturn, Uranus and Neptune. All of them are much larger than the objects of the terrestrial group. Giants have a lower density and, in contrast to the planets of the previous group, consist of hydrogen, helium, ammonia and methane. The giant planets do not have a surface as such, it is considered the conditional boundary of the lower atmosphere. All four objects rotate very fast on their axis, possess rings and satellites. The most impressive planet is Jupiter. It is accompanied by the largest number of satellites. The most impressive rings are in Saturn.

The characteristics of gas giants are interrelated. If they were close in size to the Earth, they would have a different composition. Light hydrogen can be retained only by a planet with a sufficiently large mass.

Dwarf planets

It's time to study what the solar system is - class 6. When today's adults were at this age, the cosmic picture looked a bit different for them. The scheme of the solar system at that time included nine planets. The last in the list was Pluto. So it was until 2006, when the meeting of the International Astronomical Union (IAU) adopted the definition of the planet and Pluto ceased to correspond to it. One of the points reads: "The planet dominates in its orbit." The trajectory of Pluto's motion is littered with other objects, which exceed the total former ninth planet by mass. For Pluto and several other objects, the concept of "dwarf planet" was introduced.

After 2006, all the bodies in the solar system were thus divided into three groups:

• Planets - large enough objects that managed to clear their orbit;

• Small bodies of the solar system (asteroids) - objects that are so small that they can not achieve hydrostatic equilibrium, that is, take a round or approximate form;

• Dwarf planets occupying an intermediate position between the two previous types: they reached hydrostatic equilibrium, but did not purify the orbit.

The last category today officially includes five bodies: Pluto, Eris, Makemake, Haumea and Ceres. The latter refers to the belt of asteroids. Makemake, Haumea and Pluto belong to the Kuiper belt, and Eris to the scattered disk.

Asteroid Belt

The peculiar boundary that separates the planets of the terrestrial group from the gas giants, throughout its existence, is exposed to the effect of Jupiter. Due to the presence of a huge planet, the asteroid belt has a number of characteristics. So, his images create an impression, this is a very dangerous zone for spacecraft: the ship can be damaged by an asteroid. However, this is not entirely true: the impact of Jupiter has led to the fact that the belt represents a rather sparse accumulation of asteroids. And the bodies that make it up are rather modest in size. During the formation of the belt, the gravity of Jupiter influenced the orbits of the large cosmic bodies that had accumulated here. As a result, there were constant clashes that led to the appearance of small fragments. A significant part of these debris under the influence of the same Jupiter was expelled from the solar system.

The total mass of bodies making up the Asteroid belt is only 4% of the mass of the Moon. They consist mainly of rocks and metals. The largest body on this site is the dwarf planet Ceres, followed by asteroids Pallas, Vesta and Gigeya.

Kuiper Belt

The scheme of the solar system includes one more site, inhabited by asteroids. This Kuiper belt, located beyond the orbit of Neptune. The objects located here, including Pluto, have received the name of the Trans-Neptunian. Unlike the asteroid belt, which lies between the orbits of Mars and Jupiter, they consist of ice - water, ammonia and methane. The Kuiper belt is 20 times wider than the asteroid belt and much more massive than it.

Pluto in its structure is a typical object of the Kuiper belt. He is the largest body of the region. Here are two more dwarf planets: Makemake and Haumea.

The scattered disk

The dimensions of the solar system are not limited to the Kuiper belt. Behind him is the so-called scattered disk and the hypothetical Oort cloud. The first partially intersects with the Kuiper belt, but lies much further in space. This is the place where the short-period comets of the solar system are born. For them, the orbital period is less than 200 years.

The objects of the scattered disk, including the comet, as well as bodies from the Kuiper belt, consist mainly of ice.

Oort Cloud

The space where the long-period comets of the solar system are born (with a period of thousands of years) is called the Oort cloud. To date, there is no direct evidence of its existence. Nevertheless, a lot of facts are found that indirectly confirm the hypothesis.

Astronomers suggest that the outer boundaries of the Oort cloud are remote from the Sun at a distance of 50 to 100 thousand astronomical units. In size, it is more than a thousand times the Kuiper belt and the scattered disk combined. The outer boundary of the Oort cloud is also considered the boundary of the solar system. The objects located here are exposed to the nearest stars. As a result, comets are formed, the orbits of which pass through the central parts of the solar system.

Unique structure

To date, the solar system is the only known part of the cosmos where there is life. Not least the possibility of its appearance was influenced by the structure of the planetary system and its location in the corotation circle. Earth, located in the "zone of life", where sunlight is not so destructive, could be as dead as its nearest neighbors. The comets that appear in the Kuiper belt, the scattered disk and the Oort cloud, and large asteroids could ruin not only dinosaurs, but even the very possibility of living matter. From them we are protected by a huge Jupiter, attracting to such objects or changing their orbit.

During the study of the structure of the solar system, it is difficult not to fall under the influence of anthropocentrism: it seems that the universe did everything just so that people could appear. It is probably not quite so, but a huge number of conditions, the slightest violation of which would lead to the death of all living things, are persistently inclined to such thoughts.