Explanation:
Eating surface ice from Enceladus might be healthier
than eating ice from Saturn's rings -- it certainly appears cleaner.
From their apparent densities and reflectance properties, both the
rings of Saturn and its shiniest moon,
Enceladus,
are thought to be composed predominantly of
water ice.
For reasons that are not yet understood, however, many of
Saturn's ring particles have become partly coated with some
sort of relatively dark dust, while the surface of
Enceladus appears comparatively bright and clean.
The contrast between the two can be seen in the
above image taken last month by the
robot Cassini spacecraft now in
orbit around
Saturn.
Bright Enceladus shines
in the background in contrast to the darker foreground rings.
The reason why Enceladus is so bright is currently
unknown but might involve bringing fresh water to its surface with
water volcanoes.