Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. The largest moon of Saturn is a rare wonder. Because of its thick cloud cover, however, Titan's actual surface properties remain mysterious. Voyager 1 flew by in 1980 taking the above picture, and more recently much has been learned from observations by the Hubble Space Telescope . The Cassini mission launched in 1997 will map Titan's surface in 2004, helping to solve some of its mysteries.
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