You are mixing ft and meters...Do not land on Mars or Europa. For concrete, ( that the mountain limestone is almost like..) is only 18 meters. "... analysts a

You are mixing ft and meters...Do not land on Mars or Europa. For concrete, ( that the mountain limestone is almost like..) is only 18 meters. "... analysts at Janes say the weapon can penetrate about 200 ft (60 m) of earth or 60 ft (18 m) of concrete.."