Saturday, 5 November 2011

Saturn, the planet of the rings.





(Hello! We are Kimberly and Jose Maria and we are going to publish our work about Saturn in the blog!)

Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus (the Titan father of Zeus), the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol () represents the Roman god's sickle.

Now, we are going to explain Saturn characteristics:

On one hand, the diameter of Saturn described between two points on the equator is known as the equatorial diameter.

On the other hand, the diameter which goes from one pole to the other is known as polar diameter.

So, knowing that, Saturn equatorial and polar diameters are respectively 120,536 and 108,728 kilometers. In comparison with the Earth (Equatorial diameter: 6,378.1 km, Polar diameter: 6,356.8 km) Saturn is bigger than the Earth.


Saturn average distance from Sun is 1, 429,400,000 kilometers. Comparing that data with the average distance from Sun of the Earth (149.600.000 kilometers), that support that Earth is the third planet from the Sun, and Saturn the sixth planet.

Saturn mass is 5, 688·1026 kilograms while Earth mass is 5.9736×1024 kg. So, we can appreciate a big difference of masses.

-Surface Temperatures in Saturn are the following ones:

Temperature

Celsius (Cº)

Fahrenheit (Fº)

Kelvin (K)

Min.

-191

-311.8

82

Medium.

-130

-202

143

Max.

Unknown

Unknown

Unknown

Clouds

-177

-286.6

96

The time that Saturn uses to complete one rotation , which is the same as the length of a day is 10.233 hours.

The time that Saturn uses to complete one orbit, which is the same as the length of a year is 29,458 years. This planet lasts three times more to complete one orbit than Jupiter, which lasts approximately 11 years.

For each cubic meter, Saturn weights 690 kilograms.

Saturn composition:

Though there is no direct information about Saturn's composition, it is thought that its interior is similar to that of Jupiter, having a small rocky core surrounded mostly by hydrogen and helium. The rocky core is similar in composition to the Earth, but more dense. This is surrounded by a thicker liquid metallic hydrogen layer, followed by a liquid hydrogen/helium layer and a gaseous atmosphere in the outermost 1000 km.Traces of various volatiles are also present. The core region is estimated to be about 9–22 times the mass of the Earth. Saturn has a very hot interior, reaching 11,700 °C at the core, and it radiates 2.5 times more energy into space than it receives from the Sun. Most of this extra energy is generated by the Kelvin–Helmholtz mechanism (slow gravitational compression), but this alone may not be sufficient to explain Saturn's heat production.

Saturn has 200 observed satellites which at least 62 are moons, and 53 of which have formal names. Titan, the largest, comprises more than 90% of the mass in orbit around Saturn, including the rings. Saturn's second largest moon, Rhea, may have a tenuous ring system of its own, along with a tenuous atmosphere. Many of the other moons are very small: 34 are less than 10 km in diameter and another 14 less than 50 km. Titan is the only satellite in the Solar System with a major atmosphere in which a complex organic chemistry occurs. It is also the only satellite with hydrocarbon lakes.

The composition of Saturn atmosphere is:

Gases

Hydrogen

Helium

Methane

Ammonia

HD

Ethane

%

96

3

0.4

0.01

0.01

0.0007

The enormous weight of Saturn's atmosphere causes the atmospheric pressure to increase rapidly towards the interior, where the hydrogen gas condenses into a liquid.

-Other characteristics of Saturn are:

Saturn axial inclination is 26,73°

The visible rings stretch to a distance of 136,200 km (84,650 mi) from Saturn's centre, but in many regions they may be only 5 m (16.4 ft) thick. They are thought to consist of aggregates of rock, frozen gases, and water ice ranging in size from less than 0.0005 cm (0.0002 in) in diameter to about 10 m (33 ft) in diameter—from dust to boulder size. An instrument aboard Voyager 2 counted more than 100,000 thin rings in the Saturnian system.

Saturn have vast quantities of water in the atmosphere, as components, many of the great colored bands and "smaller" spiral storms of Saturnr are composed almost entirely of liquid water , but the processes of the gas giants' atmospheres are only partially understood at this time.

-Exploration missions

There are three main phases of observation and exploration of Saturn. The first era was ancient observations (such as with the naked eye), before the invention of the modern telescopes. Starting in the 17th century progressively more advanced telescopic observations from earth have been made. The other type is visitation by spacecraft, either by orbiting or flyby. In the 21st century observations continue from the earth (or earth orbiting observatories) and from the Cassini orbiter at Saturn.

In October 1997 the Cassini spacecraft bound launched for Saturn, which also included the Huygens probe to explore Titan, the largest and most interesting of the planet's moons. This is the latest big-budget project of NASA, in collaboration with the European Space Agency and the Italian Space Agency. After a journey of nearly seven years, Cassini was scheduled to collect data on Saturn and its moons for four years. In October 2002 the spaceship got his first photograph of the planet, taken from a distance of 285 million kilometers which also appears Titan. In June 2004, Cassini flew by Phoebe, another satellite of Saturn to obtain spectacular images of its surface full of craters. In July of that year, the spacecraft entered orbit around Saturn. In January 2005 the Huygens crossed the atmosphere of Titan and reached the surface, sending to Earth data and images from satellite great interest.

Cassini–Huygens spacecraft

Saturn eclipses the Sun, as seen from the Cassini–Huygens space probe.

On July 1, 2004, the Cassini–Huygens space probe performed the SOI (Saturn Orbit Insertion) maneuver and entered into orbit around Saturn. Before the SOI, Cassini had already studied the system extensively. In June 2004, it had conducted a close flyby of Phoebe, sending back high-resolution images and data.


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