SOLAR
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AND METEORITES
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NEBULAE
GLOSSARY
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Saturn:The Ringed
World
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Name of
the Planet |
Saturn |
Position
in Solar System |
Saturn
is named after the Roman god of agriculture. Sixth planet in
the Solar System. Ringed Planet |
Constituents |
hydrogen,
helium |
Atmosphere |
hydrogen
|
Average
Distance from Sun |
1,427,000,000
km/886,000,000 mi |
Orbit
Time |
29.46 Earth
years |
Diameter |
120,000
km/74,560 mi |
Average
Density (water=1) |
0.7 |
Satellites |
Pan, Atlas,
Prometheus, Pandora, Epimetheus, Janus, Mimas, Enceladus, Tethys,
Telesto, Calypso, Dione, Helene, Rhea, Titan, Hyperion, Iapetus,
Phoebe |
Average
Surface Temp |
{msp} |
Rotational
Period |
10.23 hours |
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Description:
Saturn is the second largest planet of the
Solar System. It can easily accommodate 755 Earths inside its volume.
It has a beautiful ring system. While Galileo studied Saturn, with
his small telescope in 1610, he was surprised to see the rings as
two knob shapes, and called them as ears. But now when we look at
Saturn through bigger telescopes, we can see it as a huge, misty,
yellowish globe, with fabulous rings around it. This giant system
of hundreds of rings makes the planet one of the splendid signets
in our Solar System.
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Saturn rotates on its own axis
in just 10 hrs 14 mins and revolves around the Sun in about 29 years.
About nine Earths could be lined up along Saturn's diameter. Saturn's
average density is very low, only 70% of that of water. Like Jupiter,
Saturn is also a gaseous giant, with an atmosphere of hydrogen and
helium. However, these clouds of gas are not as turbulent and mobile
as those found on Jupiter.
The surface temperature of Saturn is around - 180 degrees C which
is too cold for ammonia to exist as a gas. So we find ammonia ice
crystals there. Saturn receives only a hundredth of the heat and
light that we receive on Earth from the Sun. Though Saturn's surface
temperature is low, at the core, the temperature soars high. The
visible features on Saturn consist of bands and other cloud patterns-
ovals, eddies and interaction spots. The image of Saturn's northern
hemisphere, taken by Voyager 1 in 1980 at a range of 9 million km,
shows an isolated convective cloud.
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Image :Rings of Saturn(False Color)
Source: NASA/NSSDC
PRESS
RELEASE TEXT
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Saturn's Rings System:
Saturn's rings are no more than 1,000 m thick.
How the rings were first formed is something of a mystery. There are
two competing theories. The first is that they are the debris left
behind after a satellite was torn apart by the gravitational forces
of Saturn. The second is that they consist of material that failed
to coalesce into a satellite at the time that planet was forming.
The second theory is now thought to be more likely. Saturn and its
magnificent ring system seem open aspect by Voyager 2's cameras. The
picture was taken four and half days after the spacecraft made its
closest approach to the planet. Dark radial markings resembling spokes
constantly dissolve and reappear, revolving with Saturn's rings.
Saturn has the larges number of satellites numbering 23. The biggest
of them is Titan. |
Interesting Facts:
-From Saturn, the Sun appears 1% as bright
as from the Earth.
-Saturn is 95 times as massive as the Earth.
-The diameter of the rings of Saturn is 225% that of the equatorial
diameter of the planet
-Saturn is the only major body in the Solar System whose density
is less than water.
-Saturn's polar diameter is only 89% of its equatorial diameter.
-With respect to the orbit of saturn, the rings are tiltes 27.3
degrees.
-844 Earths could fit inside Saturn, if Saturn were spherical.
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Historical Events
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29 July, 1027 |
The Chinese observed and
recorded an occultation of Saturn by Mars. |
1610 |
Galileo Galilei became the
first to observe Saturn's rings. |
25 March, 1655 |
Using a refractor which
provided a magnification of 50, Huygens discovered first, the
moon of Saturn - Titan. |
1672 |
Cassini discovered Rhea.
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1684 |
Cassini discovered two more
moons - Tethya and Dione. |
1790 |
Herschel determined the
rotation period of Saturn's ring to be 10 hours and 32 mins. |
1876 |
Spectacular
white spots were observed on Saturn by US astronomer Asalph
Hall. |
1 September,
1979 |
US space probe
Pioneer 11 flew by Saturn, 3500 km from the outer edge. |
15 October,
1997 |
At 8 hours 43
mins UT, as seven-year journey to Saturn began with the lift-off
of a Titan IVB/Centaur carrying the US-European-Italian Cassini
space probe. |
4 September,
2009 |
At 10 hours
19 mins UT, the Earth will pass through the ring plane of Saturn. |
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