Photograph Description

Saturn, a gas giant planet with an extensive ring system, is over 120,000 kilometres across. This sunlit equatorial view shows Saturn’s clouds and the ring system edge-on, as the dark band across centre. The moon Rhea (1528 kilometres across) is at far right. Rhea, the second-largest of Saturn’s moons, orbits outside the main ring structures, at a distance of around 470,000 kilometres from the planet’s equator. The shadow just seen at far left is from the moon Tethys. This mosaic of images was obtained on 4 November 2009, by the wide-angle camera on the orbiting Cassini spacecraft. (Photo by Science Photo Library)