| ||Automatic translation|| ||Category: Planets and dwarf planets|
Updated June 01, 2013
|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.
Two 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.
|Aphelion||1 513 325 783 km|
|Perihelion||1 353 572 956 km|
|Eccentricity||0.055 723 219|
|Orbital period||10 759.22 d or 29.4571 yr|
|Inclination||2.485 240° to Ecliptic|
|Equatorial diameter||120 536 km|
|Polar diameter||108 718 km|
|Mass||5,6846×1026 kg or 95,152 Earths|
|Synodic period||378.09 days|
|Escape velocity||35,5 km/s|
|Longitude of ascending node ||113.642811°|
|Argument of perihelion||336.013862°|
|Temperature||-191°C - 130°C|
|Number of satellites||62 only 13 of which have diameters larger than 50 km|
Rings of Saturn
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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. 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).
Image: 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.
Image: This amazing photo of the F ring taken by Cassini in June 2010, shows the deformation of the F ring, Prometheus the passage of every 15 hours. Prometheus comes very close to the ring if he disrupts the point of creating a bridge of matter between him and the ring. These particles attracted by the gravitational force of Prometheus out of the ring and just stick together on the satellite. The loss on the ring causes a cutoff point as an injury that will heal automatically in less than three months, a phenomenon called "self healing ring '(the ability to repair itself). The gravitational pull exerted on Prometheus particles of the ring closest to, and creates both a stream of ice particles, but also these amazing black ribbons hollow. Prometheus rotating faster than the particles of the ring, the small icy moon form a new notch on each pass. Prometheus shaped grain of rice, is visible in the last slot on the left. Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA
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Image: the photograph at right, taken by Voyager 2, August 22, 1981 shows the structure of rings composed phonograph abundance of ice and silicates.
The particles located between the rings A and B are remarkably similar to what has been observed Phoebe, a moon of Saturn.
These black particles revive the theory that the rings are the remnants of a moon disintegrated. The Cassini spacecraft has detected large amounts of oxygen around the rings.
This phenomenon could be explained by a collision that would have caused this substantial separation of oxygen.
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Image: 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.
Image: 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.
Image: 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.
Hexagon of the north pole of Saturn
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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.
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Image: 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.
South pole of Saturn
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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).
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Image: Credit: NASA/JPL/ Space Science Institute
Colors of Saturn
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The strange colors of the northern hemisphere of Saturn, taken by the Cassini space probe has changed since the arrival of the probe in its environment in July 2004.
The most likely explanation of its color changes is that the colors of Saturn vary with the seasons of the planet.
Above rings seen by the slice, we can see its main moon, Titan. Titan is the second largest satellite of the Solar System and the only satellite of the Solar System to possess an atmosphere.
On the magnified image of the giant planet, you can see 3 other moons, tiny dots on the edge of the rings
Image: Cassini image of splendid whose wire rings cut into two hemispheres the giant planet in our solar system. Titan flying here, like a sapphire, the disk of rings of Saturn. nota: Pour plus d'informations sur la mission Cassini-Huygens
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
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