 Enceladus ( pronounced / ɛnˈsɛlədəs / ) is the sixth @-@ largest moon of Saturn . It is approximately 500 kilometers ( 310 mi ) in diameter , about a tenth of that of Saturn 's largest moon , Titan . Enceladus is mostly covered by fresh , clean ice , reflecting almost all the sunlight that strikes it , making its surface temperature near -200 ° C (-328 ° F) . Enceladus is one of the brightest objects in the solar system, reflecting about 90% of the light that hits it. nobody knows the exact number of satellites that orbit Saturn, but there are at least