TRƯỜng thpt phan đĂng lưU

The white rings of Saturn, the second largest planet in the solar system and named for the ancient Roman god of agriculture, were first seen by the Italian astronomer Galileo in 1610. He interpreted the rings as being two smaller bodies, but in the late 1650s Huygens correctly theorized that there was indeed a ring. It was not until the mid-19^th century that J.C Maxell demonstrated mathematically that these rings were composed of minute and connected particles. In 1980, the Voyager I spacecraft showed that the ring system was highly structured.

This system is vast, some twenty one times the diameter of the Earth, but it has a maximum thickness of only two kilometers. Spectroscopy, the analysis of radiated light to determine the elements present, show that the particles in the system consist of water ice, which is likely to cover rocky silicate cores. The ring may have originated an debris from satellites or comets, though another theory holds that they may consist of material left over from the formation of the planet itself.

Apart from the myriad ring particles, themselves satellites of course, there are at least twenty-four larger satellites proper orbiting Saturn. This means that Saturn has the most extensive satellite system yet found among the nine planets of our solar system. More than one-third of Saturn's satellites have been discovered in the past twenty years. While in general less strikingly varied than the moons of Jupiter, those of Saturn do provide one notable exception. Titan. This satellite, second only in size to Jupiter's Ganymede, is unique in the solar system in having a substantial atmosphere.