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Moons of Neptune

Satellites of Neptune

 Automatic translationAutomatic translation Category: moons
Updated June 01, 2013

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.

 
Moons of
Neptune
diameter
(km)
Semi-major
axis (km)
     
Triton ≈2 706 354 759
Proteus ≈420 117 646
Nereid ≈340 5 513 818
Larissa ≈194 73 548
Galatea ≈176 61 953
Despina ≈150 52 526
Thalassa ≈82 50 074
Naiad ≈66 48 227
Halimede ≈62 16 611 000
Neso ≈60 49 285 000
Sao ≈44 22 228 000
Laomedia ≈42 23 567 000
Psamathe ≈40 48 096 000
S/2004 N1 ≈18 105 283

Triton

    

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.

Image: photography taker in 1989 by the probe Voyager 2.

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

Proteus

    

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.

Image: photography taken in august 25th 1989 by the probe Voyager 2.

 Proteus  
Proteus Moon of 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

    

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.

Image: photography taken in august 24th 1989 by the probe Voyager 2.

 Larissa moon of Neptune 
Larissa Moon of 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

    

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.

Image: photography taken in 1989 by Voyager 2.

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

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