A new study focusing on the inside of Saturn's
icy moon Mimas suggests that its cratered
surfaces hide one of two intriguing possibilities.
Either the moon's frozen core is shaped a
bit like a rugby ball, or it contains a liquid
water ocean.
Researchers used a number of images of Mimas
taken by NASA's Cassini mission to determine
how much the moon wobbles as it orbits Saturn.
They later came to the conclusion that the
data suggests that something "isn't right".
An underground ocean is one of two explanations
for why the 400-mile diameter moon wobbles.
The other possibility is that Mimas has an
oblong or rugby ball-shaped core.
Whilst scientists believe the ocean idea sounds
quite unlikely, a closer look at the moon's
eccentric orbit suggests gravitational tugging
by Saturn as the moon circles closer and then
further away could cause enough frictional
heating to melt ice and form an ocean.
