But as many new moons were discovered scientists began selecting names from more mythologies, including Gallic, Inuit and Norse stories. Over the decades, many informal names have been used on the Moon and some IAU-approved names have been officially changed.
Moons of Saturn were originally named for Greco-Roman Titans and descendants of the Titans. The lettered crater names included in the Gazetteer of Planetary Nomenclature, and therefore in this atlas, are found in the definitive source 'NASA Catalogue of Lunar Nomenclature' (NASA Reference Publication 1097).
Pan, like Saturn's moon Atlas, has a prominent equatorial ridge that gives it a distinctive flying saucer shape. These waves intersect downstream to create the wakes, places where ring material has bunched up in an orderly manner thanks to Pan's gravitational kick. This kick causes waves to develop in the gap and also throughout the ring, extending hundreds of miles into the rings. Since ring particles closer to Saturn than Pan move faster in their orbits, these particles pass the moon and receive a gravitational "kick" from Pan as they do. Pan creates stripes, called "wakes," in the ring material on either side of it. The gap is a 200 mile (325 kilometer) opening in Saturn's A ring. As it orbits Saturn every 13.8 hours, it acts as a shepherd moon and is responsible for keeping the Encke Gap open. Pan, the innermost of Saturn's known moons, has a mean radius of 8.8 miles (14.1 kilometers) and orbits 83,000 miles (134,000 kilometers) away from Saturn, within the Encke Gap of Saturn's A-ring. Showalter in 1990 using images taken by the Voyager 2 spacecraft nine years earlier.
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