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Titan et Dione, Saturn's moons

Titan et Dione seen by Cassini

 Automatic translation  Automatic translation Updated June 01, 2013

The Cassini-Huygens The Cassini-Huygens is a joint mission of NASA, the European Space Agency and the Italian Space Agency whose main purpose is to explore Saturn and its moons, particularly Titan. The idea of this mission was in 1982. The total duration of the mission is estimated at 11 years, launched 15 October 1997 until 2008. The Cassini-Huygens is composed of the Cassini orbiter, equipped with a total of 12 instruments, and the Huygens probe, equipped with six instruments. In early 2004, the spacecraft went into orbit around Saturn and 14 January 2005, the orbiter landed on Titan. space mission is a mission automatic made ​​in collaboration by the Jet Propulsion Laboratory (JPL), the European Space Agency (ESA) and the Italian Space Agency (ASI).
Its objective is to study the planet Saturn and several of its satellites, including Titan.
The Cassini-Huygens space probe, composed of the Cassini Huygens orbiter and Huygens module is orbiting around the planet.
Huygens was objective to land on the moon Titan.
The name of the mission is a tribute to Jean-Dominique Cassini, French astronomer of the seventeenth century to the origin of fundamental observations concerning Saturn, and Christian Huygens, Dutch astronomer of the same century, who discovered Titan.
The Cassini-Huygens mission has allowed to have many detailed images of Phoebe, to study in detail the structure of Saturn's rings, to study Titan thoroughly and discover the many moons of Saturn.


After a journey of nearly seven years and 3.5 billion km traveled in the solar system on the back of Cassini, Huygens landed on Titan, with its heat shields, January 14, 2005 returning to Earth, a distance of 1.2 billion km, information and spectacular images.

Image:  Titan is one of the largest moons in the solar system and its surface is constantly obscured by a thick atmosphere.
In 2005, the European Huygens probe landed on Titan, offering humanity a first glimpse of its unusual surface.
Dione, on the right, far less than a quarter of the diameter of Titan and has virtually no atmosphere.
This image was taken by Cassini on 10 April 2010.
Credit: NASA / JPL / SSI Composite color: Emily Lakdawalla

 Titan and Saturn's moons Dione, taken by cassini

Titan, Saturn's moon


Titan, Saturn's largest moon, is the second largest satellite in the Solar System.
The diameter of Titan is 5150 km, in comparison, the Earth is 12 756.28 km. In its thick atmosphere, the Cassini infrared spectrometer observed a huge cloud system covering the north pole of Titan.
Titan is the only satellite in the Solar System to possess a thick atmosphere of nitrogen (nitrogen) and methane clouds, in which one can observe a very active weather (evaporation, cloud formation, precipitation of methane).
Its atmosphere is 10 times denser than Earth's atmosphere and receives 100 times less solar energy, its average temperature is about -180 ° C.
Titan has, like the Earth, seasons very marked because of the high inclination of its axis of rotation.
Ten times farther from the Sun than the Earth, Titan takes 29 years to go around the Sun.
Its seasons last about 7 years.
The study of Titan in the coming years, we could reveal surprises concerning unimaginable ways, that life can take.

 Titan moon of Saturn 
Titan moon of Saturn
Diameter 5 151 km ±4,0 km
Mass 1,346×1023 kg
discovered in   25 mars 1655
discovered by Christian Huygens
Temperature 94 K (-180 °C)
distance of Sun 10 UA
Inclination 0,28° relative to Saturn
Atmosphere 98,4% dinitrogen
1,6% of methane
atmospheric pressure 146,7 kPa

Image: View of Titan by Cassini, October 26, 2004.
This mosaic of nine images shows the brightness variations of Titan's surface and bright clouds of methane, near the south pole.
The brightest region on the right side and equatorial region are called Xanadu.

Dione, Saturn's moon


Dione was discovered in 1672 by Giovanni Domenico Cassini. Dione is composed primarily of water as ice, but, given its higher density than the other moons of Saturn (outside of Titan, whose density is increased by gravitational compression), it probably contains a quantity large enough to more dense material, such as silicate rocks. The shots taken at 500 km away by the Cassini spacecraft, used to confirm that the plumes observed are huge white cliffs of ice that crisscross Dione.
Dione is in synchronous rotation with Saturn, it made ​​a revolution in itself for a spin around Saturn in about 66 hours.

Image: Dione, a moon among the sixty moons of Saturn

 Dione moon of Saturn 
Dione moon of Saturn
Diameter 1118 km
Mass 1,096×1021 kg
discovered in  March 21, 1684
discovered by Jean-Dominique Cassini
Density 1,44g/cm3
Temperature 87 K or -186°C
Albedo 0,55
orbital velocity 10,03 km/s
Semi-major axis 377 396 km
orbital period 66 H or 2,736915 days

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