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So far, 52 of Saturn's moons have been officially named. For the latest moons discovered visit the New Discoveries page.
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The dozens of moons orbiting Saturn vary drastically in shape, size, age and origin. Some of these moons have rocky surfaces, while others are porous, icy bodies. Many have craters, ridges and valleys, and some show evidence of tectonic activity. Some appear to have formed billions of years ago, while others appear to be pieces of a bigger, fragmented body. The most interesting one is Titan, the biggest of them all. Larger than Earth's Moon, Titan even has its own thick atmosphere -- the only natural satellite in the Solar System with such a luxury.
During its four-year mission in this immense region, the Cassini spacecraft will extensively photograph many of these moons and collect data that will increase our understanding of their composition.
To date, 52 moons have been officially named. In alphabetic order, they are: Aegir, Albiorix, Anthe, Atlas, Bebhionn, Bergelmir, Bestla, Calypso, Daphnis, Dione, Enceladus, Epimetheus, Erriapus, Farbauti, Fenrir, Fornjot, Greip, Hati, Helene, Hyperion, Hyrokkin, Iapetus, Ijiraq, Janus, Jarnsaxa, Kari, Kiviuq, Loge, Methone, Mimas, Mundilfari, Narvi, Paaliaq, Pallene, Pan, Pandora, Phoebe, Polydeuces, Prometheus, Rhea, Siarnaq, Skadi, Skoll, Surtur, Suttung, Tarqeq, Tarvos, Telesto, Tethys, Thrym, Titan and Ymir.
Astronomers keep finding new moons, both using ground-based observatories and cameras onboard Cassini. For more information on the latest moons discovered visit the New Discoveries page.
More resources are available in the Icy Satellites publications listing.
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Finding new moons orbiting a planet as distant as Saturn is a game of patience and details.
Whether they use ground-based instruments or the cameras onboard a spacecraft like Cassini, astronomers basically use the same technique: they painstakingly compare images of the sky taken at different times looking for anything that moved. Because stars are so far away, they occupy the same spots in an image -- but anything out of place could be the signature of a newly found object. If the position and orbit of a celestial body are unique, astronomers publish the findings. Later verifications will assure the moon-candidate a definitive name.
Cassini focuses its cameras mainly on objects relatively close to Saturn. The rings in particular offer a big challenge because they may "hide" moons in their midst. The rings are also very bright, complicating the discovery of moons. However, these moons are especially interesting to scientists studying the rings because they act on the ring particles. Earth-based observations, on the other hand, focus on the outer part of the Saturnian region.
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How do moons get their exotic names? Who makes the final decision? For practical reasons, a new moon is given a working title that astronomers use to identify it while waiting for the official name.
This temporary name usually consists of the year of discovery and a number indicating the order of discovery in that year. In the case of Saturn's moons, these provisory names follow the format S/2005-S1, S/2005-S2 etc.
Once the existence of the moon is confirmed and its orbit determined, the moon is given a final name by the International Astronomical Union, the organization that since 1919 assumed this task. While anybody can submit suggestions, the final decision is made by a committee within the organization called the Central Bureau for Astronomical Telegrams.
Names usually come from characters in Greek and Roman mythology. In the case of Saturn, moons are named after Saturn's brothers, the Titans, and Saturn's sisters, the Titanesses. These were mythological giants who were believed to rule in the heavens before Jupiter conquered them. So, 17 of the first discovered moons of Saturn bear those names. Titan was given its name because the moon is so much larger than the others.
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