The problem is that the crystals may well be snowflake-size or smaller, and harvesting them from other lunar material would be more challenging and costly than excavating blocks of ice.

• 问题是，结晶也可能是像雪花般大小，甚至更小，如欲从月球其他成份中获得它们，将比挖掘冰块更具挑战性，花费也高得多。