Saturn. Hubble Space Telescope image of the planet Saturn, showing the varying cloud levels in its atmosphere. Blue areas show a clear atmosphere down to the main cloud layer, whilst green and yellow areas show atmospheric haze above the cloud. Red and orange areas represent clouds reaching high into the atmosphere, whilst the dark region around the south pole is a hole in the cloud layer. The equatorial rings are composed of chunks of ice. Two moons are also visible: Dione (yellow, lower left), and Tethys (green, upper right). Image taken by the Near Infrared Camera and Multi-object Spectrometer (NICMOS).