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 |  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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 The universe is all worked up Imprimer cette page


Satellites of Neptune

      

         

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

        

Moons of Neptune

       category : satellites of planets
       

Before the flying over Neptune by the American probe Voyager-2, in 1989, only two satellites, Triton and Nereid, were known. Since thanks to this flying unless 5000 km of distance to Travel 2, Neptune is much better known. It is surrounded with a thick atmosphere on base of hydrogen, with helium and with methane. The absorption of the red radiations, by the methane is responsible, some blue tint of the planet. As we presumed it since observations made from the Earth in 1984 and 1985, Neptune is surrounded with a system of rings formed by rocks and by dusts.

  

Five different rings were identified, among which very diffuse two, at distances included between 42900 and 62900 km of the planet. The most outside contain three regions of stronger density which correspond to bows observed since the Earth. In 1989, the images taken by Voyager-2 revealed new satellites which form a regular system turning on circular and little tilted orbits. The probe also showed that the planet was surrounded with a complete system of fine rings crimped by brilliant bows. In 2003 the number of satellites of Neptune was 13.

  
Name Diameter
km		 Mass
kg
Triton 2706,8 2,140×1022
Proteus 436×416×402 5 ×1019
Larissa 208×178 5 ×1018
Galatea 204×184×144 4 ×1018
Despina 180×148×128 2 ×1018
Nereid 170 2 ×1018
Thalassa 104×100×52 4 ×1017
Naiad 96×60×52 2 ×1017
         

Triton

      

category : satellites of planets
       

Triton is seventh and bigger of the satellites of Neptune. It carries the name of the god of the Greek mythology. Its orbit is reactionary that is that its sense of rotation is set against that of the rotation of Neptune, it supposes that Triton is an outside body which was captured. The moons which have a reactionary orbit cannot have been formed in the same region of the primitive solar nebula as the planets all around of which they turn: they are thus the captured moons. This scenario because of the mass of Triton, is exceptional in the solar system, the known cases have much smaller sizes.
[photography taker in 1989 by the probe Voyager 2]

  

 
Triton   Lune de Neptune
diameter   2706,8 km
mass   2,140 ×1019 kg
discovered in   October 10th 1846
discovered  by   William Lassell
         

Proteus

      

category : satellites of planets
       

Proteus of irregular shape, is the second biggest moon of Neptune. Protée is an object very dark, looking like the soot, he reflects only 10 % of the light which strikes it. It was discovered on May 24th, 1981 by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen during an eclipse of star. Its existence was confirmed in 1989 by Stephen p. Bradford A Synnott and. Smith during the passage of the Voyager probe 2 near Neptune. Proteus is a celestial body covered with craters of impact. Proteus is the name of a marine god of the Greek mythology who could change at will shape, son of Poseidon.
[photography taken in august 25th 1989 by the probe Voyager 2]

  

 
Proteus   Lune de Neptune
diameter   436×416×402 km
mass   5 ×1019 kg
discovered in   may 24th 1981
discovered  by   Harold J. Reitsema William B. Hubbard Larry A. Lebofsky David J. Tholen
         

Larissa

      

category : satellites of planets
       

Larissa of irregular shape, is the fifth moon of Neptune. It was discovered by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen during an eclipse of star by Neptune May 24th, 1981. Its existence was confirmed by Stephen p. Synnott during the passage of the Voyager probe 2 near Neptune in 1989. The orbit of Larissa, close to the planet, is unstable and declines towards Neptune. Larissa will form a new ring or will be absorbed by Neptune. In the Greek mythology, Larissa is a girl of Triopas, a king of Argos.
[photography taken in august 24th 1989 by the probe Voyager 2]

  

 
Larissa   Lune de Neptune
diameter   208×178 km
mass   5 ×1018 kg
discovered in   may 24th 1981
discovered  by   Harold J. Reitsema
William B. Hubbard
Larry A. Lebofsky
David J. Tholen
         

Galatea

      

category : satellites of planets
       

Galatea of irregular shape, is the fourth moon of Neptune. It was discovered during the passage of the Voyager probe 2 in 1989. its name comes from a Nereid (marine nymph) of the Greek mythology. The orbit of Galatea, close to the planet, is unstable and declines towards Neptune. Galatea will form a new ring or will be absorbed by Neptune.
[photography taken in 1989 by the probe Voyager 2]

  

 
Galatea   Lune de Neptune
diameter   204×184×144 km
mass   4 ×1018 kg
discovered in   1989
discovered  by   Stephen P. Synnott
         

Related subjects

      

category : satellites of planets
       

Satellites of Jupiter

        

Satellites of Saturn

        

Satellites of Mars

        

Satellites of Neptune

        

Satellites of Uranus

        
         

| 

 |  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.

|
 The universe is all worked up Imprimer cette page


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Astronomy - october 15th 2007