The only sources?Rare lunar meteorites, soil from Soviet probes, and the 842 pounds of rubble carted back by Apollo astronauts from 1969 to 1972.

• 仅有的资源包括稀少的月岩，苏联探测器传回的月球土壤和1969-1972年阿波罗宇航员带回的842磅重的的碎石。