Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. This picture gives an indication of Saturn's extensive ring system , which can be seen casting a shadow on the planet, as does Tethys. Saturn 's rings are composed of many chunks of ice ranging in size from a pebble to a car. The rings have several large gaps, the largest of which is clearly visible in the picture and is named the Cassini Division , after its discoverer . Saturn appears brighter than most stars in the sky, and its rings can be discerned with a small telescope.
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