Editing Hyperion (moon) (section)

=== Composition ===
[[File:Hyperion in natural colours.jpg|195px|thumb|right|True-color image of Hyperion, taken by the [[Cassini spacecraft|''Cassini'' spacecraft]]]]
Like most of [[Saturn's natural satellites|Saturn's moons]], Hyperion's low [[density]] indicates that it is composed largely of water ice with only a small amount of rock. It is thought that Hyperion may be similar to a loosely accreted [[Rubble pile|pile of rubble]] in its physical composition. However, unlike most of Saturn's moons, Hyperion has a low [[albedo]] (0.2–0.3), indicating that it is covered by at least a thin layer of dark material. This may be material from [[Phoebe (moon)|Phoebe]] (which is much darker) that got past [[Iapetus (moon)|Iapetus]]. Hyperion is redder than Phoebe and closely matches the color of the dark material on Iapetus.

Hyperion has a [[porosity]] of about 0.46.<ref name="Thomas2007" /> Although Hyperion is the eighth-largest moon of Saturn, it is only the ninth-most massive. [[Phoebe (moon)|Phoebe]] has a smaller radius, but it is more massive than Hyperion and thus denser.<ref name="Thomas2010" />