System solar | | | | |
| automatic translation | | | | |
The solar systems | | | | category : solar system |
| | | | |
Our planetary system possesses only a single star, the Sun. However thanks to the spatial telescope Spitzer, the astronomers observed that the multiple planetary systems, with two, three stars or more, are numerous. Such systems tend to form a central pair, the other constituents playing troublemaker's role with regard to the orbital movement of the group. More of half of the systems with stars are exactly binary, it is completely likely that the universe is constituted by planets revolving around two stars.
" There is nothing which prevents the formation of a planetary system in the binary systems ", indicates David Trilling of the university of Tucson in Arizona. " He could exist of uncountable planets with two suns or more.
" The astronomers knew that planets could form in the strongly separated binary systems, among which stars are 1000 times as distant some of others than distance between the Earth and the Sun, that is 1000 astronomical units (UA).
On 200 planets discovered except our Solar system, approximately 50 revolve around one of the stars of a very vast binary system. | |  The star the closest to the Sun, Proxima Centauri, in 1,3 parsec, is a triple star. The most brilliant both constituents have a maximal separation of 35", corresponding to a half-main line centre of 23.5 UA and a period of revolution of 80 years. The movement of the third constituent is not known with a sufficient precision to end definitively, but we think that it is physically associated with two others, because it shares the same parallax and appropriate movement. it is situated in 2.2° two other, with period orbital of at least 250 000 years...
The solar system is the name given to the planetary system consisted of the Sun and the heavenly objects revolving around him. By extension, the term solar system can be sometimes employed to indicate the other planetary systems. | | 
|
| | | | | |
| Our solar system and its planets | | | | category : solar system |
| | | | |
Our solar system is constituted by the Sun, by eight planets, by three dwarfish planets, as well as the small bodies as asteroids and comets, with their satellites. In the center is situated the Sun, our star which contains 99,86 % of the mass of all the system. The inside of the Sun has a density and a temperature such as thermonuclear reactions occur, loosening enormous quantities of energy. The biggest part of this energy is freed in the space in the form of electromagnetic radiations, mainly in the form of visible light. The Sun also emits a stream of charged particles called the solar wind. This solar wind interacts strongly with the magnetosphere of planets and contribute to eject gases and dusts except the solar system.
Planets the most close to the Sun are the telluric, small, rocky and dense planets, with a slow rotation, a solid surface, no rings and few satellites. By leaving the Sun, we find Mercury, Venus, Earth and Mars. Beyond Mars there is a belt of asteroids Of numerous small rocky bodies called asteroids are present in the solar system, an important part of them circulate in a ring, between the orbit of Mars and that of Jupiter (2 - 4 UA (symbol : UA) The distance averages of the Earth in the Sun. An UA is worth 149 597 871 km. It is a unity often used for the distances in the solar system, or for the space of two stars in a double system. ), in what the astronomers call the belt of asteroids, otherwise called main belt.
Beyond, still opens the domain of the huge, gaseous and little dense planets, with a nucleus of weak dimension: Jupiter, Saturn, Uranus and Neptune. Beyond, Pluto, Eris and the other objects of the belt of Kuiper.
Pluto is the second dwarfish planet of the solar system by the size. It belongs to the belt of Kuiper. | | The solar system, which counted nine planets since 1930, contains no more than eight since August, 2006 (Pluto was added to the list of the minor objects of the solar system and saw attributing the number 134340 in the catalog of the minor objects). | | This belt, populated with thousand asteroids, is the reservoir of comets in short period. |
| |   The planets of the solar system are not obviously represented to the scale
see the real orbits of the planets of the solar system
|
| | | | | |
| The solar system and its objects | | | | category : solar system |
| | | | |
The solar system is really much more complex than it appears to it, if we consider all its objects. A considerable number of objects is in the belt of Kuiper and still beyond in the cloud of Oort.
On the image below, the Belt of Kuiper and the Cloud of Oort, are represented to the scale, the small blue task in the center is the space occupied by the solar system such as we are in the habit of seeing it, that is constituted by its 8 planets.
The Belt of Kuiper in a very widely superior diameter (5 - 10 times) that of the "classic" solar system.
The Cloud of Oort is one diameter 1000 time superior in that of the classic solar system. | | 
|
| | | | | |
| Birth of the solar system | | | | category : solar system |
| | | | |
The event takes place there is 4,5 billion years in the neighborhood of a spiral arm of the Galaxy. In a nebula of opaque rotating gas, of small heap constitute. Among them, our future Sun escapes from it.
Its companions scatter in the Milky Way.
In the center of this future still gaseous system, a star forms, helped by the force of gravity it contracts. The solar system belongs to a galaxy among the billion galaxies constituting the universe. | | 
|
| | | | | |
During this young period the central temperature increases. This cloud is going to contract still until reach temperatures of some million degrees.
This heating of the heart is going to engage the started of the thermonuclear reactor.
In this phase protons join freeing from the energy under the influence of the nuclear strength.
It is the fusion of the hydrogen in helium which stops the contraction of the star and which stabilizes its volume. The rising solar system | | 
|
| | | | | |
| Our Sun is is born | | | | category : solar system |
| | | | |
Let us remind that our Sun got 99,8 % of the total mass of its system. The rest of the warm gaseous nebula of the departure, the composition of which is identical to that of the Sun, continues to lose some heat.
It arrives one moment when we reach the temperature which certain chemical compounds are not stable any more in the gaseous state.
These compounds are thus going to condense, not in liquids but in solids, because the pressure is very weak. The nebula thus takes care of solid grains, dusts which we thus call condensats Solid grains of condensed chemical and mineralogical compounds be born in nebulas, following that we call: the sequence of condensation. The first compounds which condense in 1300°C, are oxides rich in titanium, aluminum and calcium. Towards 1050°C condenses massively the metal iron, then towards 950°C, the first silicate in this particular case the silicate of magnesium and iron. Towards 800°C, form silicates with more cowardly structures, feldspars and iron sulphide. In even lower temperatures condenses a silicate containing some water and in 0°C the water condenses icy..
It is these grains which, by accumulating under the influence of the gravitation, are going to give birth to more and more big solid objects; at first, in meteorites, then later, in planets. The solar system is is born | | 
|
| | | | | |
| Life cycle of the Sun | | | | category : solar system |
| | | | |
In 5 billion years our Sun will have transformed all its hydrogen into helium.
A new period of contraction is going to warm the nuclei of helium which combined 3 by 3 will give some carbon and 4 by 4 of the oxygen. The outside layers are going to swell and to cool and our celestial body will become a giant red as, Arcturus, Betelgeuse, Antares and many others at present. During this time its heart continues to contract until reach the temperature which is going to light the thermonuclear reactor with fusion of helium to make some carbon. | | This phase will last hardly a million years. All the matter of the close planets is vaporized.
The successive fusion of the carbon and the oxygen will give birth to nuclei precious as the magnesium, the aluminum, the silicon which constitute our ground rocks, as the phosphor and suffers it the main part in the elaboration of the life.
These phases of fusion will be more and more short, we shall arrive at the end of the reserves of matter.
The Sun will die and returning its matter to the distant space. | | It will not be more that a white dwarf so the buckle closes. Every star contributes to enrich the middle, of absent heavy elements at the beginning. 10 % of stars are dwarfs. These stars at the end of life have already lived our time and enriched the matter which allowed us to live. The death of the Sun will sow the germs of the other forms of life...
SOMEWHERE ELSE ! |
| | | | | |
Distances with regard to the Sun | | | | category : solar system |
| | | | |
| Objects | Distance of the Sun (millions Km) | Sidereal revolution in years | Speed orbital average in Km/s | Equatorial diameter in Km | Albedo (coefficient of reflection) | | Mercury | 57,9 | 0,241 | 47,9 | 4880 | 0,055 | | Venus | 108,2 | 0,615 | 35 | 13004 | 0,61 | | Terre | 149,6 | 1 | 29,8 | 12756 | 0,34 | | Mars | 227,9 | 1,881 | 24,1 | 6796 | 0,15 | | Jupiter | 778,412027 | 11,317 | 13,0572 | 142984 | 0,52 | | Saturn | 1427 | 29,458 | 9,6 | 120536 | 0,42 | | Uranus | 2870 | 84,015 | 6,8 | 51118 | 0,45 | | Neptune | 4496 | 164,788 | 5,4 | 49528 | 0,54 | | Pluto | 5946 | 247,7 | 4,7 | 2390 | 0,60 | | Moon | | | | 3476 | 0,073 |
|
| Objects | Density in g / cm ² | mass in earth mass | Escape speed in km/s | Duration of rotation (equator) | Inclination (equator) | | Mercury | 5,3 | 0,0553 | 4,3 | 58,646 j | 0° | | Venus | 4,95 | 0,815 | 10,4 | 243,019j | 178° | | Terre | 5,52 | 1 | 11,2 | 23H56 | 23,5° | | Mars | 3,95 | 0,1074 | 5,1 | 24H37 | 24° | | Jupiter | 1,33 | 317,833 | 61 | 9H50 | 3° | | Saturn | 0,69 | 95,159 | 36,7 | 10H14 | 27° | | Uranus | 1,56 | 14,499 | 22,4 | 10H49 | 98° | | Neptune | 2,27 | 17,204 | 25,5 | 15H40 | 30° | | Pluto | 4 | 0,0025 | 4 | 153H17 | 99° | | Moon | | | 2,37 | | |
|
| Objects | Magnitude | Color | Temperature | Reflection of the receive light (Albedo) | Size apparent | | Sun | - 26,86 | | 6000° | | 16' | | Moon | - 12,5 | | | 7,3% | | | Mercury | - 1,9 | | + 425° to -273° | 5,5% | 4,8" to 13,3" | | Venus | - 4,4 | | 100° | 61% | 10" to 64" | | Terre | | | +50° to -50° | 34% | | | Mars | - 2,8 | Orange | + 24° to -130° | 15% | | | Jupiter | - 2,5 | | 150° to -145° | 41% | | | Saturn | - 0,4 | | -150° | 42% | | | Uranus | + 5,6 | Green | -170° | 45% | | | Neptune | + 7,3 | | -150° | 54% | | | Pluto | + 14,5 | | -230° | 40% | 0,04" |
|
