New simulations suggest Europa’s massive ice shell may seal its hidden ocean off far more completely than scientists ever realized. New simulations suggest that Europa’s ice shell may not be a cracked doorway into its hidden ocean, but an imposing barrier that rapidly freezes water trying to escape. Simulations Challenge a Promising ShortcutIn a study published in Nature Astronomy, Ojha and his colleagues modeled how ocean water might move through narrow fractures in Europa’s ice shell. “Can liquid water rise from Europa’s deep ocean toward the surface without freezing along the way?” “Our work suggests that Europa’s ice shell may be a stronger barrier between the ocean and the surface than previously assumed,” Ojha said.