Explanation:
Each moon of Saturn seems to come with its own
mystery.
Rhea, Saturn's second largest moon behind
Titan, shows unusual wisps, visible above as light colored streaks.
Higher resolution images of similar wisps on Dione indicate that they
might be made of long braided fractures.
Rhea is composed mostly of
water ice,
but likely has a
small rocky core.
Rhea's rotation and orbit are locked together, just like
Earth's Moon, so that one
side always faces Saturn.
A consequence of this is that one side always leads the other.
Rhea's leading surface is much more heavily
cratered than the trailing surface, pictured above.
The above image in natural color was taken last month by the
Cassini robot spacecraft in orbit around Saturn.
