ALL THESE WORLDS ARE YOURS, EXCEPT EUROPA. ATTEMPT NO LANDING THERE. Ice blades threaten Europa landing. “Jupiter’s icy moon Europa is a prime target for future space missions as it harbours a buried ocean that could have the right conditions for life. But attempts to land may face a major hazard: jagged “blades” of ice up to 10m long.”

Arthur C. Clarke reference courtesy of Matt Hurley.