The moon is generally thought to be a dry place, and the discovery of water on its surface comes as an unexpected — and exciting — surprise for researchers. Carolina K. Smith/ hide caption

toggle caption Carolina K. Smith/

This radar image taken by Cassini in July 2006 of Titan, one of Saturn's moons, provides convincing evidence that it is covered by large bodies of liquid. NASA/JPL/Space Science Institute hide caption

toggle caption NASA/JPL/Space Science Institute

This 'butterfly' nebula was captured with Hubble's newly updated imaging. NASA hide caption

toggle caption NASA

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