Saturn, Cassini image. A section of the planet's rings are visible at left. They are casting shadows over Saturn's northern hemisphere. The varying densities are responsible for the varying darkness of the shadows. Dione, one of Saturn's moons is at top. This image was taken in visible light with the wide-angle camera onboard the Cassini spacecraft. It was obtained at a distance of approximately 1.2 million kilometres from Saturn, on February 4th 2007.