For the next four minutes they plummeted down, down, deep into the ice crust of Ganymede.

They return severely wounded and covered by ice crust.

A moment after the impact, the ice crust gave way, and the nearly-elemental water beneath the surface gushed out, carrying the wreckage with it.

By the time the capsule had returned and made its third descent, the whole party was together again deep inside the ice crust of Ganymede.

Its ice crust could be up to 8 or 10 miles thick.

But when the ice crust is firm above the twenty foot drifts, they range far and forage where they will.

The bluish glow wasn't hanging in the air- it came through the ice crust that covered the walls of the conduit.

Europa reveals more dynamic and recent movement of this nature, suggesting a thinner ice crust.

In Ganymede a thick and solid ice crust then formed.

But the ice crust had broken and fallen in, and the valley floor beneath was dry.