Saturn - HD 影片檔

Saturn and its rings, animated Cassini image. The planet and its rings are lit by the Sun, which is behind the planet in this view. This angle allows the study of features of the rings and atmosphere that are not visible in other views. There are also two moons at lower left: Enceladus (nearer rings) and Tethys (bottom left). This view, taken from a distance of around 800,000 kilometres, combines infrared, red and violet spectral filters. Saturn is a gas giant planet with an average radius about nine times that of Earth and a volume of over 800 Earths. Its large ring system consists of thousands of chunks of rock and ice. The image was obtained on 17th October 2012, with the wide-angle camera of Cassini's Imaging Science Subsystem (ISS). The Cassini spacecraft has been surveying the Saturnian system since 2004, with its mission scheduled to end in September 2017