planets  8 planets of the solar system (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) and their satellites. sun The Sun is in 2/3 of the galactic center towards the edge, at a distance of 30 000 light years of the center. The Sun moves in a speed of 230 km/s around this galactic center during its revolution which it makes in 250 million years. galaxies The Galaxy, it is the name datum in our galaxy, it is an enormous spiral wheel of stars, a diameter of 100 000 light years. What appears of the Earth, it is a white continuous band called the Milky Way. bigbang There is 15 billion years a tremendous explosion of light gives birth to the space, in time, in the matter, a chaos burning with an inconceivable heat, a formless porridge which is going to swell, to extend in all the directions and to cool quite slowly. quotations Some quotations of big men (Aristote, Galilee, Newton, Platon, Laplace, Einstein). links Some external links concerning the astronomy.

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dwarf planets According to the definition which was approved on August 24th, 2006, during the 26th General assembly of the UAI ( International Astronomical Union), three bodies reach the status of dwarfish planet: Pluto, eris, and Ceres. Others objets should soon join this nomenclature. solar system The solar system is really much more complex if we take into account all the objects being a part of the system. A considerable number of objects is in the belt of Kuiper and still beyond in the cloud of Oort. galaxy groups Heap of galaxies are the biggest structures of the Universe. They are constituted by hundreds of galaxies connected together by their own gravitational attraction. Between the galaxies we find some material constituted by warm gas there, forming a plasma, the temperature of which reaches 10 to 100 million degrees. comets Besides planets, satellites and asteroids, the solar system contains comets (hair in Greek). The roaming comets originate in the depths of the space in several lights years. The number of periodic comets is of the order of 2000. biographies Some biographies, Einstein, Baade, Lyot, Hale, Hubble, Shapley, Laplace, Maxwell, Newton, Herschel, Kepler, Galilee, Aristotle... glossary Definition of certain words or expressions used on this site in link with the astronomy.

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| articles Christian's articles in link with the astronomy (history of the Earth, the electron, the neutrons stars, the rings of Saturn, the particles, the threat of asteroids, journey in the universe up to the atom)... exoplanets Exoplanets are situated by definition outside our solar system. Seen the large number of existing galaxies and the large number of stars which they contain, the search for these exo-planets or extra solar planets, is unlimited. constellations A constellation is a group of stars of the sky which enough close relations looked the appearance imagination of a figure onto the sky. nebulas Of the Latin 'nebula' which wants to say cloud, clouds of gas and dusts in the middle of stars, nebulas are at the same moment active crèches and cemeteries of stars. These magnificence of the sky are lit by the stars which they contain or by stars situated behind them. telescopes A telescope is constituted by a mirror which concentrates the light resulting from the observed celestial body and from the objective which supplies an enlarged image with it. The increase and the luminosity are proportional on the surface of the mirror. The presence of the ground atmosphere limits the performances of a telescope. It is to mitigate this inconvenience that spatial telescopes were placed in the space. bibliographies Some interesting books in link with the astronomy. faq Some simple answers concerning the universe which surrounds us.

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| asteroids Numerous small rocky called bodies 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 in 2 to 4 UA.

rings The rings of Saturn are one of more beautiful and of the most surprising spectacles of the solar system. That is why on July 1st, 2004, the spaceship Cassini-Huygens reduced its speed to be captured by the gravity of Saturn to enter in orbit with this one. stars A star is a celestial body similar to the Sun, which shines thanks to nuclear reactions which occur in its center. multiverse The universe is an expanding cosmic bubble. This bubble creates a new bubble which produces it the others etc.... Quantities of the other universes which give birth to the other universes, it is an interesting idea but which remain at the moment very speculative. space probes These instruments that are space probes, perceive in the detail the forms and the composition of objects of the distant regions and offer us exceptional sights of an unequalled precision. elements The most usual and practical presentation of the diverse chemical elements is the periodic board of elements also called Table of Mendeleyev. The atoms which have the same number of protons but a number different from neutrons are called isotopes. aurora A polar aurora called aurora borealis in the north hemisphere and the aurora australis in the southern hemisphere, is a brilliant phenomenon characterized by sorts of veils extremely colored in the night-sky.

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 The universe is all worked up Imprimer cette page


Saturn

     

         

Mercury Mercury the first planet of the solar system in 57,9 million km of the sun is, its diameter is 4880 km.  Venus Venus the second planet of the solar system in 108,2 million km of the sun is, its diameter is 13000 km.  Earth Earth the third planet of the solar system in 149,6 million km of the sun is, its diameter is 12756 km.  Mars Mars the fourth planet of the solar system in 227,9 million km of the sun is, its diameter is 6800 km.  Jupiter Jupiter the fifth planet of the solar system in 778 million km of the sun is, its diameter is 143000 km.  Saturn Saturn the sixth planet of the solar system in 1427 million km of the sun is, its diameter is 120500 km.  Uranus Uranus the seventh planet of the solar system in 2870 million km of the sun is, its diameter is 51120 km.   Neptune Neptune the eighth planet of the solar system in 4496 million km of the sun is, its diameter is 49530 km. 
Moon Earth possess that a single natural satellite, the Moon which orbits in 160000 km of the earth.   satellites of Mars Mars possess 2 known natural satellites, Phobos and Deimos. They orbit near the planet, in some thousand kilometres of this one.   satellites of Jupiter Jupiter possess more than 60 known natural satellites, among which Ganymede, Io, Callisto, Europe and the others... 
  satellites of Saturn Saturn possess 59 known natural satellites, of which Titan, Rhea, Japet, Dioné, Thetys, Enceladus, Mimas, Hyperion, Phoebe, Janus, Epimethea, Promethea, Pandore and the others...  satellites of Uranus Uranus possess at least 27 known natural satellites, among which Titania, Oberon, Umbriel, Ariel...  satellites of Neptune Neptune possess tens of known natural satellites, of which Triton, Proteus, Larissa, Galatea, Despina, Nereid, Thalassa, Naiad...
 

automatic translator

       
The god Chronos      

category: planets


       

Saturn In the Roman mythology, Saturn is the God of the agriculture. In the Greek mythology Saturn is associated with the God Cronos son of Uranus and Gaia and father of Zeus (Jupiter).  is warm (12000 °C in the nucleus) and irradiate more energy in the space which it receives from it of the Sun. Most of this supplementary energy are generated by the mechanism Kelvin-Helmholtz Mechanism of Kelvin-Helmholzt: in astrophysics it is the proposed mechanism by Lord Kelvin and Helmholzt who takes place when the surface of a star or a planet cools. This cooling pulls a decline of pressure and the celestial body compensates for it by contracting. This compression pulls then a reheating of the celestial body (observable mechanism on Jupiter and Saturn). , quite as for Jupiter. However it is not sufficient to explain the luminosity of Saturn. Galilee was the first one to observe it through a telescope of its fabrication in 1610. It was diverted by the appearance of Saturn. It was necessary to wait for 1659 so that Christian Huygens interprets correctly the geometry of the rings of Saturn. These rings remained a unique fact in the solar system until 1977 when a slender ring was discovered around Uranus and a little later around Jupiter and around Neptune. 2 important rings (In and B) and a weaker ring ( C ) can be observed by the Earth. The interval between rings A and B is called division of Cassini. The less visible hole in the ring A is called division of Encke.

 

The images sent to Travel revealed four weak supplementary rings (D, E, F and G). The rings of Saturn, contrary to those the other gaseous giants, are very brilliant and although they seem solid seen by the Earth, rings are constituted in fact by thousand small elements of a size varying from a centimeter to some kilometers. The rings of Saturn are extraordinarily thin. Their diameter of more than 250 000 km, does not exceed 200 meters in thickness. In spite of their impressive appearance, there is little matter in rings: if they were concentrated in a single homogeneous body, rings would form a body of hundred of kilometers. Rings seem to be mainly constituted by ice but they could also contain silicates (rocks) covered with ice. Saturn consists of hydrogen and helium which diffuses in the ultraviolet ray and the blue.

 
Saturn   characteristics
equatorial diameter   120 536 km
polar diameter   108 718 km
mass   5,6846×1026 kg
volume   827 130 milliards de km3
gravity   8,96 m/s2
escape speed   35,5 km/s
distance of the Sun   1 421 179 772 km
9,5 ua
period of revolution   10 757,7365 days
29 years et 165 days
inclination   2,484 46°
discovered in   antic
discovered by   Philolaos de Crotone
temperature   -191°C - 130°C
number of satellites   56 in 2006
         

Rings of Saturn

     

category: planets


       

 

Photo of Saturn in true colors taken on March 27th, 2004 by Cassini in 300 million kilometers of Saturn. The globe seems orange-colored revealing an atmosphere loaded with methane, these rings seem this afternoon transparent as the ring C (ring close to the planet). Rings seem to throw a blue light on the globe of Saturn, the solar light passes through rings and the small particles contained in rings diffuse strongly the blue light, thrown so on the globe of Saturn.

 

It is on the photo, the summer in the southern hemisphere while the north hemisphere is in winter. The violent winds of the planet are owed at the speed of rotation of Saturn. Saturn turns so fast in 10 hours only that the centrifugal force obliges winds to blow at the same time as the equator what gives this effect of streak horizontal that we observe.

         

 

 

         

This photo of planet Saturn in true colors, taken in October, 2004 by Cassini in 800 thousand kilometers of Saturn, shows the structure in long-playing records of rings consisted in abundance of ice and silicates. Rings and satellites form quite coherent one influencing mutually and respecting a balance operated by the flight mechanics. This balance is however fragile and will have a short duration of life (some hundreds of million years).

 

This surprising photo of the ring F taken by the probe Cassini at the end of 2004, show the deformation of the ring F in the passage of Prometheus, satellite of Saturn. Prometheus touches of if near the ring that he perturbs it in the point to create a bridge of matter between him and the ring. These particles attracted by the strength of gravitation of Prometheus go out of the ring and come to gather together on the satellite. The loss of matter of the ring provokes then a point of cut as a wound which is going to heal automatically within three months, called phenomenon ' self healing boxing ring ' (capacity to repair alone).

 

Photography taken by the Voyager probe 2, on August 22nd, 1981.
Particles situated between rings A and B look like outstandingly what was observed on Phoebe, one of the moons of Saturn. These black particles relaunch the theory according to which rings would be the rests of the split moon. The Cassini probe detected big quantities of oxygen around rings. This phenomenon could explain by a collision which would have provoked this substantial separation of oxygen.

         

Remarkable photos

     

category: planets


       

 

 

         

This photo taken by the probe Cassini in December, 2004, shows the satellite Dione, walking past the magnificent huge planet, the Saturn. Dione, discovered in 1672 by Giovanni Domenico Cassini, is one diameter 1118 kilometers and its color of grey surface, contrasts with the color yellow pastel orange of Saturn.

 

This high resolution photo, shows in detail a piece of the satellite Phoebe. We see a crater of huge impact (with regard to 220 km of Phoebe) in the indented edges there. Collapsed custard tarts are smoothed by a coat of ice.

 

This image taken by means of the red, green and blue filters was combined to produce this sight in natural color. Pictures were realized with the camera wide-angle lens of the space probe Cassini on February 4th, 2007 at a distance of 1,2 million kilometers of Saturn and at 679 000 kilometers of Rhea. The resolution is 68 kilometers by pixel on Saturn and about 40 kilometers by pixel on Rhea.

         

The hexagon of the north pole of Saturn

     

category: planets


       

A surprising hexagonal image of the set which surrounds the North Pole of Saturn in approximately 78 degrees of north latitude, was sent to us by the infrared spectrometer of the space probe Cassini. Initially discovered and observed for last time by a spatial machine during the flying over Voyager probes at the beginning of the 80s, this polar hexagon observed here at the end of 2006 seems to be a phenomenon of an exceptional longevity. The previous images of Voyager and ground telescopes suffered from their line of vision, which placed the just hexagonal structure on the limb of the planet.
" It is a really very strange phenomenon ", declares Kevin Baines, member of the team Cassini and the specialist of the instrument VIMS (visual and infrared mapping spectrometer) in the JPL (Jet Propulsion Laboratory), Pasadena, California. " We ever examined nothing of such on any other planet. Saturn is surrounded with a thick atmosphere where the currents of convection and the cellular formations dominate, and it is indeed the last place where we could expect to discover a hexagonal geometrical figure so perfect. And nevertheless, it is there ".

 

This hexagon is relatively similar to the polar whirlpool of the Earth, winds of which blow in a circular configuration around the pole. But the comparison stops there, because on our planet its shape is perfectly rounded off while on Saturn, the same whirlpool represents a perfect hexagon. The structure sinks profoundly inside the atmosphere of Saturn and a whole system of clouds circulate under the hexagon and seem to cross it.
" The differences between the aspect of both poles of Saturn are really stunning ", announces Bob Brown, the other specialist of the instrument VIMS at the university of Arizona, Tucson. " In the south pole we have a sort of hurricane with a huge eye, and in the north pole we discover this completely different geometrical structure ".
Until now, Cassini was still able to observe the hexagon of Saturn only by means of its instruments sensitive to the infrared, because the north pole is plunged at night polar, which lasts about fifteen years. The passed on images were recorded in a 5 micron wavelength during a period of 12 days beginning October 30th, 2006. In coming two years, the structure will go out gradually of the shadow and can appear in visible light.

 

This detailed image of the boreal region of the planet Saturn is an infrared image of the hexagonal structure which was realized on October 29th, 2006 at a distance of 902 000 km (image). In this hexagon, four objects of the size of the Earth could return there.
To sound the deep atmosphere, the infrared instruments of Cassini detect the thermal light which shines with depths of Saturn. Situated clouds approximately 75 kilometers lower than those visible in the normal wavelengths block this light, which seems dark. To show the brilliant or white clouds rather than sink, the contrast of the initial image was inverted to produce the image above.

         

The south pole of Saturn

     

category: planets


       

Sight taken by the probe Cassini, on a wide plan in the region of the south pole of Saturn, the shadow of the planet masks rings and Mimed icy, shine below to the left of the image. This sight showing a side enlightened by rings is taken under an angle about 28 degrees below rings. The use of the red, green and blue spectral filters were combined to create this colored sight. The image was acquired with the camera short lens on February 20th, 2007, at a distance of approximately 1 million kilometers of Saturn. The definition is 58 kilometers by pixel.

 

The mission Cassini-Huygens is a cooperative project of NASA, the European Space agency and the Italian Space agency. The Jet Propulsion Laboratory is a Californian division of the Institute of Technology in Pasadena which manages the mission for the Scientific Direction of the NASA. The space probe Cassini and its two cameras of edge were conceived, developed and assembled to JPL (Jet Propulsion Laboratory).

know more about it on the mission Cassini-Huygens

 

Credit : NASA/JPL/ Space Science Institute

         

Related subjects

     

category: planets


       

Mercury

 

Jupiter

   

Venus

 

Saturn

   

Terre

 

Uranus

   

Mars

 

Neptune

   
         

planets  8 planets of the solar system (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) and their satellites. sun The Sun is in 2/3 of the galactic center towards the edge, at a distance of 30 000 light years of the center. The Sun moves in a speed of 230 km/s around this galactic center during its revolution which it makes in 250 million years. galaxies The Galaxy, it is the name datum in our galaxy, it is an enormous spiral wheel of stars, a diameter of 100 000 light years. What appears of the Earth, it is a white continuous band called the Milky Way. bigbang There is 15 billion years a tremendous explosion of light gives birth to the space, in time, in the matter, a chaos burning with an inconceivable heat, a formless porridge which is going to swell, to extend in all the directions and to cool quite slowly. quotations Some quotations of big men (Aristote, Galilee, Newton, Platon, Laplace, Einstein). links Some external links concerning the astronomy.

|

dwarf planets According to the definition which was approved on August 24th, 2006, during the 26th General assembly of the UAI ( International Astronomical Union), three bodies reach the status of dwarfish planet: Pluto, eris, and Ceres. Others objets should soon join this nomenclature. solar system The solar system is really much more complex if we take into account all the objects being a part of the system. A considerable number of objects is in the belt of Kuiper and still beyond in the cloud of Oort. galaxy groups Heap of galaxies are the biggest structures of the Universe. They are constituted by hundreds of galaxies connected together by their own gravitational attraction. Between the galaxies we find some material constituted by warm gas there, forming a plasma, the temperature of which reaches 10 to 100 million degrees. comets Besides planets, satellites and asteroids, the solar system contains comets (hair in Greek). The roaming comets originate in the depths of the space in several lights years. The number of periodic comets is of the order of 2000. biographies Some biographies, Einstein, Baade, Lyot, Hale, Hubble, Shapley, Laplace, Maxwell, Newton, Herschel, Kepler, Galilee, Aristotle... glossary Definition of certain words or expressions used on this site in link with the astronomy.

 |

| articles Christian's articles in link with the astronomy (history of the Earth, the electron, the neutrons stars, the rings of Saturn, the particles, the threat of asteroids, journey in the universe up to the atom)... exoplanets Exoplanets are situated by definition outside our solar system. Seen the large number of existing galaxies and the large number of stars which they contain, the search for these exo-planets or extra solar planets, is unlimited. constellations A constellation is a group of stars of the sky which enough close relations looked the appearance imagination of a figure onto the sky. nebulas Of the Latin 'nebula' which wants to say cloud, clouds of gas and dusts in the middle of stars, nebulas are at the same moment active crèches and cemeteries of stars. These magnificence of the sky are lit by the stars which they contain or by stars situated behind them. telescopes A telescope is constituted by a mirror which concentrates the light resulting from the observed celestial body and from the objective which supplies an enlarged image with it. The increase and the luminosity are proportional on the surface of the mirror. The presence of the ground atmosphere limits the performances of a telescope. It is to mitigate this inconvenience that spatial telescopes were placed in the space. bibliographies Some interesting books in link with the astronomy. faq Some simple answers concerning the universe which surrounds us.

 |

| asteroids Numerous small rocky called bodies 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 in 2 to 4 UA.

rings The rings of Saturn are one of more beautiful and of the most surprising spectacles of the solar system. That is why on July 1st, 2004, the spaceship Cassini-Huygens reduced its speed to be captured by the gravity of Saturn to enter in orbit with this one. stars A star is a celestial body similar to the Sun, which shines thanks to nuclear reactions which occur in its center. multiverse The universe is an expanding cosmic bubble. This bubble creates a new bubble which produces it the others etc.... Quantities of the other universes which give birth to the other universes, it is an interesting idea but which remain at the moment very speculative. space probes These instruments that are space probes, perceive in the detail the forms and the composition of objects of the distant regions and offer us exceptional sights of an unequalled precision. elements The most usual and practical presentation of the diverse chemical elements is the periodic board of elements also called Table of Mendeleyev. The atoms which have the same number of protons but a number different from neutrons are called isotopes. aurora A polar aurora called aurora borealis in the north hemisphere and the aurora australis in the southern hemisphere, is a brilliant phenomenon characterized by sorts of veils extremely colored in the night-sky.

|


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Astronomy - october 15th 2007