This is a composite image of the small moons of Saturn.
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The Composition of Small Moons
What can be seen of the small moons may suggest a rocky composition because the surfaces seem to be covered with craters as if it were very hard. Composition is generally determined by detailed measurements of the spectra
of an object. But most of the small moons are too
small to be observed, so observations of this kind have yet to be made.
An idea of the general composition can be guessed, however, from the density. The density of typical terrestrial iron or silicate rock is between 3 and 5 g/cm3. The density of terrestrial water ice is 1.0 g/cm3. When Voyager flew by some of the small moons of the Saturnian system, it measured the mass, and so determined the densities to be about 1.2 (refer to the reference information for exact measurements of the small moons), which is closer to that of ice than rock, so most of these moons must be made out of ice, just as the icy moons are.
The fact that they are small and icy suggests a certain path for their evolution.
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