Horizontal bands and puffy swirls can be seen in this image of Saturn captured by NASA's Cassini spacecraft. The features resemble those on the planet Jupiter, although they are not as brightly colored because the clouds are covered by a thick layer of haze. Saturn's atmosphere is composed mainly of hydrogen and helium with traces of other substances such as methane and water ice. The clouds are churned violently by high winds that can exceed 1,100 miler per hour (1,800 km per hour) at the equator. Dark bands near the bottom of the image are the shadows of Saturn's rings.