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| Sunday, 12 December 2004 |
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Junior Observer |  |
| News Business Features Editorial
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Saturn : Lord of the rings is still a mystery
In 1610, Galileo, through his telescope, saw some unusual rings around Saturn and thought the rings were two moons, one on each side of the planet. But many years later, Dutch astronomer, Christian Huygens solved this mystery and described Saturn as being surrounded by a thin flat ring. Even after hundreds of years of Saturn watching, there is so much that astronomers do not yet know about the planet and its rings. It has now been discovered that not only Saturn but planets such as Uranus, Jupiter and Neptune also have rings. But, Saturn's rings stand out because they are very bright and contain lots of material. According to experts, the brightness of Saturn's rings is due to their make-up. The rings are made of icy material which reflect sunlight, just as ice does on Earth. Though they look continuous from the Earth, the rings are actually composed of innumerable small particles, each in an independent orbit. They range in size from a centimetre or so to several metres. A few kilometre-sized objects are also likely. Saturn's rings are extraordinarily thin. Though they are 250,000 km or more in diameter they are less than one kilometre thick. Despite their impressive appearance, there is very little material in the rings. If the rings were compressed into a single body, it would be no more than 100 km across. Saturn's outermost ring is a complex structure made up of several smaller rings along which 'knots' are visible. Scientists speculate that the knots may be clumps of ring material or mini moons. There are many complexes between some of Saturn's moons and the ring system. Some of the moons are clearly important in keeping the rings in place. However, the whole system is very complex and as yet poorly understood. The rings are not made up of solid sheets of material, which range in size from dust grains to boulders. These particles gently collide with each other as they go around Saturn. The rings orbit Saturn just as our Moon goes around our planet. The collisions between the ring particles are what makes the ring system so thin. The origin of the rings of Saturn is unknown. Though it may have had rings since its formation, the ring systems are not stable and must be regenerated by ongoing processes. Saturn and its ring system is so special that three space craft have visited the planet over the past 30 years to take some close-up views. Saturn was first visited by NASA's Pioneer 11 in 1979 and later by Voyager 1 and Voyager 2. None of the spacecraft, however, has landed on the ringed planet. ***** Cassini's travels
Named Cassini, after the Italian astronomer who studied the planet in the 1600s, the spacecraft spent nearly seven years travelling to Saturn.The seasoned traveller finally arrived on July 1, 2004. The spacecraft flew through the faint, wispy outer rings and settled into orbit around Saturn. Scientists hope Cassini will help explain how and when Saturn's rings were formed, why there are gaps between the rings and even why Saturn has such a spectacular ring system.Cassini will orbit Saturn for at least four years. **** Saturn- fact file * Saturn is the sixth planet from the Sun and the second largest planet. This ringed planet is visibly flattened when viewed through a small telescope.This is due to its rapid rotation and fluid state. The other gas planets are also flattened but not as much as Saturn. * In the night sky, Saturn is easily visible to the naked eye. Though it is not as bright as Jupiter, it is easy to identify as a planet because it doesn't twinkle like the stars do. * Saturn is the least dense of the planets; its specific gravity is less than that of water. * Its interior is similar to Jupiter's, consisting of rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Traces of liquid ices are also present. * Saturn's interior is hot and it radiates more energy into space than it receives from the Sun. * It has 30 unnamed satellites plus one discovered in 2003 and two in 2004 that are yet unnamed. |
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| Politics | Produced by Lake House |
Many years ago, ancient sky watchers gazing into the night sky saw a
star that shone brighter than most of the other stars. They began to
investigate and many years later identified it as Saturn, the sixth planet
from the Sun and the second largest in the solar system.
Although astronomers have spent about 400 years studying Saturn, they
are yet to discover significant information about Saturn and its ring
system. A spacecraft designed to study Saturn, its moons and its complex
ring system has settled into orbit around the planet.
