Solar System - a tiny structure in the Universe.Moreover, its size for a man is truly daunting: each of us living on the fifth largest planet can hardly even estimate the magnitude of the Earth.The modest size of our house, probably be felt only when you look at it from the window of a spacecraft.A similar feeling arises while browsing images of the telescope "Hubble": The universe is huge and the solar system occupies only a small portion thereof.However, it was her we can learn and explore, using the data obtained for the interpretation of the phenomena of deep space.
Ecumenical coordinates
Location of the solar system, scientists determined by circumstantial evidence, because we can not see 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.Orion Arm, so named because it runs close to the constellation of the same name, is considered one of the main branch of the galactic arms.The sun is located closer to the edge of the disk, rather than to the center: Distance to the latter is about 26 thousand light years.
Scientists believe that the location of a piece of our universe has one advantage over the other.On the whole galaxy of the Solar System, the Milky Way has stars that because of the nature of their movement and interaction with other objects that are immersed in the spiral arms, it emerges from them.However, there is a small area called corotation Circle, where the speed of stars and spiral arms of the same.Placed here cosmic body is not exposed to violent processes characteristic of the sleeves.By corotation circle refers to the sun and planets.This situation is considered to be one of the conditions that contributed to the emergence of life on Earth.
scheme of the solar system
central body of any planetary community - is a star.The name of the solar system provides an exhaustive answer to the question of light moves around the Earth and its neighbors.Sun - the star of the third generation, located in the middle of its life cycle.It shines more than 4.5 billion years.Approximately the same number around the turn of the planet.
scheme of the solar system now has eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune (about what happened to Pluto, below).They are conventionally divided into two groups: terrestrial planets and gas giants.
«relatives»
first type planets, as the name implies, includes Earth.In addition to her belong to it Mercury, Venus and Mars.All of them have a set of similar characteristics.The terrestrial planets are composed mainly of silicates and metals.They are characterized by a high density.They all have a similar structure: an iron core wrapped with a mixture of nickel silicate mantle, the top layer - the cortex, including the compounds of silicon and incompatible elements.This structure is broken only by Mercury.The smallest and closest planet to the Sun does not have the crust: it is destroyed bombardment.
biggest planet of the group - is the Earth, followed by Venus, then Mars.There is a certain order of the solar system: terrestrial planets make up its interior and separated from the gas giants of the asteroid belt.
more planets
The number of gas giants include Jupiter, Saturn, Uranus and Neptune.They are all much larger than terrestrial objects.Giants have a lower density and, unlike previous planetary group consisting of hydrogen, helium, ammonia, and methane.The giant planets are not as such a surface, it is considered to be notional boundary of the lower layer of the atmosphere.All four objects very quickly rotate around its axis, possess rings and satellites.The most impressive on the size of the planet - Jupiter.It is accompanied by the largest number of satellites.At the same time the most impressive rings - Saturn.
Features gas giants are interrelated.If they were approaching the size of Earth, it would have a different composition.Easy hydrogen can keep only the planet, which has a relatively large mass.
Dwarf planet
It's time to examine what is the solar system - Grade 6.When today's adults were at this age, space picture looked to them somewhat differently.Diagram of the solar system at that time consisted of nine planets.The final list is Pluto.It was not until 2006, when the meeting IAU (International Astronomical Union) adopted the definition of a planet, and Pluto ceased to meet him.One of the points is: "The planet is dominant in its orbit."The trajectory of Pluto blocked by other objects, exceeding a total of the former ninth planet by weight.For Pluto and several other objects it introduced the concept of "dwarf planet."
After 2006, all the bodies in the solar system were thus divided into three groups:
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planets - objects large enough, managed to clear its orbit;
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small bodies of the solar system (asteroids) - objects with such a small size that they can not reach hydrostatic equilibrium, that is, take a round or close to it form;
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dwarf planet, occupying an intermediate position between the two previous types: they have achieved hydrostatic equilibrium, but not cleared orbit.
today officially last category includes five bodies: Pluto, Eris, Makemake, Haumea, and Ceres.The latter refers to the asteroid belt.Makemake, Haumea and Pluto belongs to the Kuiper belt and Eris - scattered disc.
Asteroid Belt
kind of boundary that separates the terrestrial planets of the gas giant, for its existence is exposed to Jupiter.Because of the presence of the huge planet's asteroid belt has a number of features.Thus, it creates the impression of an image, it is very dangerous for the spacecraft zone: the ship may be damaged asteroid.However, this is not quite true: the impact of Jupiter led to the fact that the belt is pretty sparse cluster of asteroids.And the body, its components are quite modest in size.In the process of forming a belt of Jupiter's gravity influenced the orbits of large space bodies that are stuck here.As a result of constant clashes that led to the appearance of small fragments.Much of this debris under the influence of the same Jupiter was expelled from the solar system.
total mass of the bodies that make up the Asteroid Belt, is only 4% of the mass of the Moon.They consist mainly of rock and metal.The largest body in this area is the dwarf planet Ceres, followed by the asteroid Pallas, Vesta, and the gig.
Kuiper Belt
scheme of the solar system includes another plot populated by asteroids.This Kuiper Belt is located beyond the orbit of Neptune.The objects are placed here, including Pluto, are called trans-Neptunian.In contrast to the asteroid belt lies between the orbits of Mars and Jupiter, they are composed of ice - water, ammonia and methane.The Kuiper Belt is 20 times wider than an asteroid and much more massive than it.
Pluto in its structure is a typical object of the Kuiper Belt.It is the largest area of the body.It also placed two more dwarf planets: Makemake and Haumea.
scattered disc
dimensions of the solar system are not limited to the Kuiper belt.Behind him is the so-called scattered disc and the hypothetical Oort cloud.The first overlaps with the Kuiper belt, but it goes much further in space.This is where the short-period comets originate solar system.They are characterized by an orbital period of less than 200 years.
scattered disk objects, including comets, as well as bodies of the Kuiper belt, composed mainly of ice.
Oort Cloud
space where long-period comets originate solar system (with a period of thousands of years), called the Oort cloud.To date, no direct evidence of its existence.Nevertheless, a lot of facts found, indirectly confirming the hypothesis.
Astronomers speculate that the external borders of the Oort cloud removed from the Sun at a distance of 50 to 100 thousand astronomical units.According to its size, it more than a thousand times the Kuiper belt and scattered disc together.The outer limit of the Oort cloud, and is considered to be the boundary of the solar system.Located objects are exposed to nearby stars.As a result, they formed comets with orbits that pass through the central part of the solar system.
unique structure
Today the Solar System - the only known part of the space, where there is life.Last but not least the possibility of its occurrence has influenced the structure of the planetary system and its placement in corotation circle.The land is located in the "habitable zone" where sunlight becomes less destructive, could be just as dead as its nearest neighbors.Comets originating in the Kuiper belt, the scattered disc and the Oort cloud, and large asteroids could destroy not only the dinosaurs, but even the very likelihood of living matter.From them we protect the huge Jupiter, attracting the similar objects or changing their orbit.
During the study of the structure of the solar system's hard not to be influenced by anthropocentrism: it seems as if the universe is made everything just so that people can come.Perhaps it is not so, but a huge number of conditions, the slightest breach of which would have led to the death of all living things, hard incline to such thoughts.
